This project will provide nitrate, pesticide and other water quality data for private wells and public water utilities across Iowa to use in modeling drinking water exposures for members of the Agricultural Health Study cohort.

Intensive private drinking water well sampling in Carroll County, Iowa, will be conducted in 2007 – 2008 as part of the Comprehensive Assessment of Rural Health in Iowa (CARHI) project. This sampling will be a cooperative effort with the ongoing Iowa Statewide Rural Well Water Survey Phase 2 (SWRL2), a three year project (2006-08) conducted by CHEEC in collaboration with the Iowa County Health Departments and County sanitarians, the Iowa Departments of Public Health and Natural Resources, and other agencies. The intensive sampling effort in Carroll County will include 50 wells for the entire suite of SWRL2 compounds (nutrients, bacteria, metals, pesticides and herbicide degradates). Research questions of interest for this set of wells include are there seasonal variation for certain analytes in a confined geographic area (county), and what are the risk factors related to well characteristics/proximate sources of contaminants for poor water quality? An additional 100 wells will sampled and analyzed for total coliform bacteria, E. coli, enterococci, somatic coliphage, and chloride, as part of a special microbial monitoring study conducted by the University Hygienic Laboratory. The research objectives of the microbial monitoring study are to determine the incidence of enterovirus in private drinking water wells, to determine the occurrence of traditional and non-traditional fecal indicators in groundwater (e.g. somatic coliphage, chloride, and enterococci), and to determine whether the source of fecal pollution is human (by utilizing a human specific molecular marker).

Research and database management on the Comprehensive Assessment of Rural Health in Iowa (CARHI) in collaboration with the UI Departments of Geography, Occupational and Environmental Health, and Family Medicine. Funding is provided by the CDC.

Comprehensive Assessment of Rural Health in Iowa (CARHI)—NCEH is funding and providing technical oversight to a 2- to 3-year cooperative surveillance activity that is generating baseline health data for selected rural communities in Iowa. With input from a CARHI committee of stakeholders, the Iowa Department of Public Health (IDPH) is linking environmental and health data from a rural community to allow investigation of health effects possibly associated with the environment, such as effects associated with agricultural exposures. The CARHI committee is developing a tool and process for collecting data and a CARHI database. The committee also is recruiting communities and health care practitioners to participate in the CARHI project. Public health officials will use CARHI data to monitor communities’ health, identify existing or emerging health problems that warrant further investigation, enhance or guide environmental sampling, conduct comprehensive health studies, or target important public health programs such as smoking cessation and safe farming practices.

Heartland Radon Research and Education Program (HRREP)

The Iowa Radon Lung Cancer Study

Phase I Completed

^a Field, R.W., ^aLynch, C.F., ^bSteck, D.J., ^aSmith, B.J., ^aBrus, C.P., ^cNeuberger, J.S.,
^aWoolson, R.F., ^aFisher, E.F., ^d Platz,C.E., ^d Robinson, R.A.

^aCollege of Public Health
University of Iowa

^b Physics Department
St. Johns University

^c Department of Preventive Medicine
University of Kansas School of Medicine

^dCollege of Medicine
University of Iowa

The Iowa Radon Lung Cancer Study was a large-scale epidemiology study initiated in 1993 and funded by the National Institute of Environmental Health Sciences (NIEHS). The study assessed the risk posed by residential radon exposure. The 5-year study was performed in Iowa and the participants were women throughout Iowa who lived in their current home for at least 20 years. Over a thousand Iowa women took part in the study. Four hundred and thirteen of the participants were women who had developed lung cancer, the remaining 614 participants were controls who did not have lung cancer. The study was limited to women, because they historically tend to spend more time at home and they have less occupational exposure to other lung carcinogens.

The epidemiologic study was performed in Iowa for several reasons. Iowa has the highest average radon concentrations in the United States. In addition, women in Iowa tend to move less than most other states, which makes calculation of their past radon exposure easier. Iowa was also selected because it has a quality National Cancer Institute SEER cancer registry, which helped us identify women who developed lung cancer. Close to 60% of the basement measurements for both cases (participants with lung cancer) and controls (participants without lung cancer) exceeded the EPA's action level. Twenty-eight percent of the living areas for the controls and 33% of the living areas for the cases exceeded the EPA's action level of 4 pCi/L.

The study used the most advanced radon exposure measurement techniques ever performed in a residential radon study. Numerous yearlong radon measurements were made in each participant's home. Outdoor radon measurements were also performed in addition to estimates of work place exposure. All these measurements were linked to where the participants spent the proceeding 20 years in order to get a cumulative radon exposure.

The major paper reporting the findings was published in volume 151 of the American Journal of Epidemiology (pages 1081-1101) in 2000. The American Journal of Epidemiology is the premier scientific journal devoted to the publication of empirical research findings and methodologic developments in the field of epidemiologic research. Findings of the study were released to the press on May 25, 2000.

Risk estimates for the Iowa Radon Lung Cancer Study were adjusted for age, active smoking, and education. For all lung cancer subtypes, there was a positive categorical trend (p = 0.05). Analyses restricted to the live cases and controls noted both a strong categorical (p = 0.01) and continuous trend (p = 0.03). The Iowa Radon Lung Cancer Study's estimated excess odds at 11 WLM5-19 (roughly equivalent to a 15-year exposure at an average radon exposure of 4 pCi/L) averaged 0.50 for both all cases and the live case subset. For the all-case category, large cell carcinoma exhibited a statistically significant trend for both the continuous (p = 0.04) and categorical (p = 0.03) risk estimates. However, the differences in the linear excess odds between histologic types was not statistically significant (continuous p = 0.58, categorical p = 0.65). Overall, these results suggest that cumulative radon exposure is a significant risk factor for lung cancer in women.

The Iowa Radon Lung Cancer Study had several strengths. First, independent pathologic review was performed for 96 percent of the cases. Second, the study was carried out in Iowa, which has the highest mean radon concentrations in the United States. Third, the high radon concentrations in conjunction with a strict quality assurance protocol contributed to accurate and precise radon measurements. Fourth, the IRLCS criteria requiring occupancy in the current home for at least the last 20 years eliminated the need to impute radon measurements from missing homes. Fifth, the linkage between radon measurements and retrospective participant mobility allowed for a refined exposure estimate. The IRLCS risk estimates are in general agreement with the National Research Council's predicted cancer risk associated with indoor radon exposure. Overall, the risk estimates obtained in this study suggest that cumulative radon exposure in the residential environment is significantly associated with lung cancer risk.

THE IOWA and MISSOURI RESIDENTIAL RADON STUDIES

Phase II – Currently Underway

RW Field, Ph.D. ^a, DJ Steck, Ph.D. ^b, BJ Smith, Ph.D.^a, CF Lynch, M.D. Ph.D.^a,
JH Lubin, Ph.D.^c, MA Parkhurst, Ph.D.^d, MCR Alavanja, Dr. PH ^c

^aCollege of Public Health
University of Iowa

^bPhysics Department
St. John's University

^c National Cancer Institute
Rockville, MD

^d Pacific Northwest National Laboratory
Richland, WA

Purpose

The specific aims of the 5-year Iowa and Missouri Residential Radon Studies (Phase-II), which initiated in 2000 are to: 1) further refine the estimated lung cancer risk posed by residential radon-222 (radon) decay product exposure using a novel glass-based retrospective radon decay product (progeny) reconstruction detector; 2) determine the shape (linear, quadratic, etc.) of the dose-response curve relating radon progeny exposure and lung cancer; 3) determine the lung cancer risk posed by radon progeny exposure for the various histologic types; and 4) examine the association between radon progeny and other lung cancer risk factors on the lung cancer incidence. The study, using state-of-the-art methods to measure retrospective radon progeny exposure, focuses on the association between residential radon progeny exposure and lung cancer.

Glass surfaces exposed to radon gas over an extended period of time are convenient radon progeny reservoirs that allow retrospective estimates of radon exposure. The novel glass-based detectors measure ²¹⁰Pb previously embedded in glass through residual nuclei recoil implantation following alpha decay. Glass provides a stable matrix for the ²¹⁰Pb deposit. The 22-year half-life of ²¹⁰Pbmeans that it takes decades before the activity achieves an equilibrium value and the activity persists for years after exposure. This predictable temporal behavior provides a long-lasting marker for past radon and radon progeny concentrations in a home. Therefore, one can measure glass items that have been carried from home to home over long periods of time to estimate past residential radon progeny exposure. Because the radon progeny deliver the actual radiation dose to the lung tissues, rather than the radon gas itself, better residential radon progeny dose estimates require the reconstruction of actual airborne radon progeny concentrations. Pooling of data between two large-scale epidemiologic studies from a similar geographic area that used the glass-based detectors in addition to the contemporary radon gas detectors increases the power of the overall analyses. We anticipate the research will significantly reduce radon (more precisely radon progeny) exposure misclassification, which will enhance our ability to address the Specific Aims above.

Study Design

The study design has three major components: 1) field calibration and laboratory validation of the retrospective radon detectors, 2) reanalysis of the risk estimates from the Iowa Radon Lung Cancer Study incorporating radon progeny exposure estimates obtained from retrospective radon detector (RRD) measurements, rather than radon gas measurements; 3) calculation of risk estimates from a pooled analyses of retrospective radon detectors exposure results for the previous National Institutes of Environmental Health Sciences (NIEHS) funded Iowa Radon Lung Cancer Study (IRLCS) and the National Cancer Institute (NCI) funded Missouri Radon Lung Cancer Study II (MRLCS-II).

Selected Findings

Findings from the Iowa and Missouri Residential Studies have been published in over 25 peer-reviewed scientific journals. A few examples of some of the major findings follow.

Risk Estimates for Prolonged Residential Radon Exposure Risk estimates for the Iowa Radon Lung Cancer Study using estimates of retrospective gas exposure were adjusted for age, active smoking, and education. For all lung cancer subtypes, there was a positive categorical trend (p = 0.05). Analyses restricted to the live cases and controls noted both a strong categorical (p = 0.01) and continuous trend (p = 0.03). The Iowa Radon Lung Cancer Study's estimated excess odds at 11 WLM5-19 (roughly equivalent to a 15-year exposure at an average radon exposure of 4 pCi/L) averaged 0.50 for both all cases and the live case subset. Large cell carcinoma exhibited a statistically significant trend for both the continuous (p = 0.04) and categorical (p = 0.03) risk estimates, but the differences in the linear excess odds between histologic types was not statistically significant. These results suggest that cumulative radon exposure is a significant risk factor for lung cancer in women.

Improved Residential Radon Study Methodology – The a priori defined IRLCS radon-exposure model produced higher odds ratios than those methodologies that did not link the subject's retrospective mobility with multiple, spatially diverse radon concentrations. In addition, the smallest measurement errors were noted for the IRLCS exposure model. Risk estimates based solely on basement radon measurements generally exhibited the lowest risk estimates and the greatest measurement error. The findings indicate that the power of an epidemiologic study to detect an excess risk from residential radon exposure is enhanced by linking spatially disparate radon concentrations with the subject's retrospective mobility and that previous epidemiologic investigations likely underestimated the risk posed by residential radon exposure.

State of the Art Radon and Radon Progeny Dosimetry - Radon progeny, rather than radon, deliver dose to the lungs during decade’s long exposures. The study has made advances in estimating contemporary and past radon progeny dose using passive integrating alpha detectors. Contemporary airborne radon and progeny activities are reconstructed from direct radon and surface deposited progeny measurements. Track registration material, with selected energy removing filters, detects the individual alpha emitting isotopic concentrations. These concentrations are used in a fate and transport model to calculate the available airborne dose rate. Retrospective radon progeny concentrations can be reconstructed from glass-implanted ²¹⁰Po activity and the relationship between airborne and deposited activities determined from contemporary activities. Using a regression analysis of the IRLCS retrospective detector data to identify the important environmental variables, new detector modules, as well as the old, have been calibrated in controlled exposures. Active airborne progeny detectors are being developed and calibrated to directly sample the important environmental conditions and activities in a select group of homes to improve and validate the dose estimates.

Diet and Lung Cancer - When comparing the fifth (highest) to the first (lowest) quintile of consumption of total fat, saturated fat and cholesterol in the IRLCS, we obtained odds ratios of 2.0 (1.3-3.1), 3.0 (1.9-4.7), and 2.0 (1.3-3.0), respectively for lung cancer. However, when red meat was entered into the model along with total fat, saturated fat or cholesterol, the excess risk for the macronutrients disappeared while an odds ratio of 3.3 (1.7-7.6) was obtained for red meat. The odds ratios for red meat consumption were similar among adenocarcinoma cases, OR=3.0 (1.1-7.9) and non-adenocarcinoma cases, OR=3.2 (1.3-8.3) and among life-time nonsmokers and ex-smokers OR=2.8 (1.4-5.4), and current smokers, OR=4.9 (1.1-22.3). Yellow-green vegetables were protective with an odds ratio of 0.4 (0.2-0.7). We concluded that consumption of red meat was associated with an increased risk of lung cancer even after controlling for total fat, saturated fat, cholesterol, fruit, yellow-green vegetable consumption and smoking history, while yellow-green vegetables are associated with a decreased risk of lung cancer.

Gene Environment Interactions – Recent work with collaborators at the NCI and City of Hope (Los Angeles) have explored gene-environment interactions between residential radon, environmental tobacco smoke (ETS), and the GSTM1 null genotype. The sample series included lung cancer cases pooled from three previously completed case-control studies. Recent results show a statistically significant 3-fold increase in the interaction OR for GSTM1 null cases compared with GSTM1 present cases. In addition, the ETS and GSTM1 interaction OR was significantly elevated over two-fold. This is the first study to provide evidence of a radon and GSTM1 interaction in risk of lung cancer and supports the hypothesis that radon and ETS may promote neoplasia by damaging genetic pathways that include GSTM1. These findings have just been submitted for publication.

Future Plans

Laboratory calibration of the retrospective radon progeny detector is nearing completion and field validation studies are planned for fall of 2004. As soon as this work is complete, we will perform a reanalysis of the IRLCS data using the glass-based retrospective radon progeny data. Next, we will pool the glass-based retrospective radon progeny data from both the IRLCS and MRLCS. The pooled data should allow more power to examine the lung cancer risk posed by residential radon decay product exposure and determine whether the risk varies by histologic type. We are also continuing our collaboration with European investigators pooling the findings from all the residential radon studies that have used standard radon gas measurements and plan an eventual pooling of residential radon studies that incorporated the use of the more advanced glass-based measurements. Further collaborations are also underway with researchers at NCI and City of Hope (Los Angeles) to explore additional studies examining gene-environment interactions and lung cancer. We have archived paraffin fixed tumor specimens from the Iowa Radon Lung Cancer Study and welcome the opportunity of additional collaborations using these materials. We are also interested in performing future studies in Iowa, with the cooperation of the NCI SEER Iowa Cancer Registry, examining the impact of environmental causes of lung cancer in relation to energy balance in never-smoking individuals.

Selected Peer-Reviewed Scientific Publications from the Iowa Residential Radon Study and On-going NCI-Sponsored Iowa and Missouri Residential Radon Studies

1. Field RW, Steck DJ, Lynch CF, Brus CP, Neuberger JS, Kross BC. Residential Radon-222 Exposure and Lung Cancer: Exposure Assessment Methodology. Journal of Exposure Analysis and Environmental Epidemiology 6(2):181-195, 1996.

2. Field RW, Smith BJ, Brus CP, Lynch CF, Neuberger JS, Steck DJ. Retrospective Temporal and Spatial Mobility of Adult Iowa Women, Risk Analysis: An International Journal 18(5):575-584, 1998.

3. Fisher EF, Field RW, Smith BJ, Lynch CF, Steck DJ, Neuberger JS. Spatial Variation of Residential Radon Concentrations: The Iowa Radon Lung Cancer Study, Health Physics 75(5):506-513, 1998.

4. Field RW, Lynch CF, Steck DJ, Fisher EF. Dosimetry Quality Assurance: The Iowa Residential Radon Lung Cancer Study, Radiation Protection Dosimetry 78(4):295-303, 1998.

5. Steck DJ, Field RW, and Lynch CF. Exposure to Atmospheric Radon (²²²Rn) in Central North America, Environmental Health Perspectives 107(2):123-127, 1999.

6. Field RW, Lynch CF, Steck DJ, Smith BJ, Brus CP, Neuberger JS, Woolson RF, Fisher EF, Platz CE, Robinson RA. Iowa Radon Lung Cancer Study, Radiation Research 151:101-103, 1999.

7. Field RW, Steck DJ, Smith BJ, Brus CP, Neuberger JS, Fisher EF, Platz CE, Robinson RA, Woolson RF, Lynch CF. Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study, American Journal of Epidemiology 151(11):1091-1102, 2000.

8. Field RW, Steck DJ, Smith BJ, Brus CP, Neuberger JS, Fisher EF, Lynch CF. The Iowa Radon Lung Cancer Study Phase I: Residential Radon Gas Exposure and Lung Cancer, The Science of the Total Environment 272:367-72, 2001.

9. Steck DJ, Field RW. The Use of Track Registration Detectors To Reconstruct Contemporary and Historical Airborne Radon (²²²Rn) and Radon Progeny Concentrations for a Radon-Lung Cancer Epidemiologic Study, Radiation Measurements 31(1-6):401-412, 1999.

10. Field RW, Steck DJ, Parkhurst MA, Hahaffey JA, Alavanja MCR. Intercomparison of Retrospective Radon Progeny Measurement Devices, Environmental Health Perspectives 107:905-910, 1999.

11. Alavanja MCR, Field RW, Sinha R, Brus CP, Shavers VL, Fisher EL, Curtain J, Lynch CF. Lung Cancer Risk and Red Meat Consumption Among Iowa Women, Lung Cancer 34 (1):37 - 46, 2001.

12. Field RW, Smith BJ, Lynch CF, Steck DJ. Intercomparison of Radon Exposure Assessment Methods: Implications for Residential Radon Risk Assessment, Journal of Exposure Analysis and Environmental Epidemiology 12(3):197-203, 2002.

13. Steck DJ, Alavanja MCR, Field RW, Parkhurst MA, Bates DJ, Mahaffey JA. ²¹⁰Po Implanted in Glass Surfaces by Long Term Exposure to Indoor Radon, Health Physics 83(2):261-271, 2002.

14. Krewski D, Lubin J, Zielinski J, Alavanja M, Catalan V, Field RW, Klotz J, Létourneau E, Lynch C, Lyon J, Sandler D, Schoenberg J, Steck D, Stolwijk J, Weinberg C, Wilcox H A. A Combined Analysis of North American Case control Studies of Residential Radon and Lung Cancer: An Update. Radiation Research 158(6):785-790, 2002.

15. Field RW. (Invited paper): A Review of Residential Radon Case-Control Epidemiologic studies Performed in the United States, Reviews on Environmental Health 16 (3), 2001.

16. Field RW, Smith BJ, Platz CE, Robinson RA, Brus CP, Lynch CF. Agreement Between SEER Reported Versus Independently Reviewed Lung Cancer Morphologies: A Quality Assurance Analysis, Journal of the National Cancer Institute 96(14):1105-7, 2004.

17. Krewski D, Lubin J, Zielinski J, Alavanja M, Catalan V, Field RW, Klotz J, Létourneau E, Lynch C, Lyon J, Sandler D, Schoenberg J, Steck D, Stolwijk J, Weinberg C, Wilcox HA. North American Case-Control Studies of Residential Radon and Lung Cancer, Journal of Toxicology and Environmental Health, In Press.

18. Krewski D, Lubin J, Zielinski JM, Alavanja M, Field RW, Letourneau EG, Sandler DP, Schoenberg JB, Weinberg C, Wilcox S, Catalan V. Risk of Lung Cancer in North America Associated with Residential Radon, Epidemiology, In Press.

For additional information on these studies contact:

R. William Field, M.S., Ph.D.
The University of Iowa
College of Public Health
Department of Occupational
and Environmental Health
Department of Epidemiology
104 IREH
Iowa City, Iowa 52242
Phone: 319-335-4413
Fax: 319-335-4225
Email: bill-field@uiowa.edu

**********************************************

GENERAL RADON INFORMATION

• An overview of radon occurrence and health risk downloaded in PDF file format.

• Information on radon testing and mitigation is available toll free from the National Safety Council at 1-800-SOS-RADON, or by visiting the EPA Web site.

• Maps of indoor and outdoor radon concentrations in the upper Midwest can be found at the Minnesota Radon Project map web pages.

• American Association of Radon Scientists and Technologists

• Conference of Radiation Control Program Directors

• National Environmental Health Association

• R.William Field's keynote address titled Current National and International Scientific Radon-Related Activities and Educational Initiatives given at the Fifteenth National Radon Meeting in 2005. Download the PowerPoint presentation.

  Notes: This will download the powerpoint presentation to your computer. You will need Microsoft powerpoint to open/see the presentation. If you are having trouble, sometimes it is best to select the option 'Save file' when prompted, open powerpoint, and then open the downloaded file (CRCPDweb.ppt). In our tests, both Firefox and MS Internet Explorer browsers running on a Windows XP machine and the latest version of Microsoft office had no problem downloading and viewing the file. The file size is 2.14 MB. The full file path is http://cheec.uiowa.edu/sites/cheec.uiowa.edu/files/CRCPDweb.ppt.

• RADON: Top 10 Reasons for Action. The following is a powerpoint presentation created by Dr. Field that may serve as a template for radon outreach presentations. The presentation builds in part on previous slides presented by the U.S. EPA for outreach purposes. Please feel free to use for your outreach activities, but acknowledgement of source of materials would be appreciated. Some of the slides in the presentation contain speaking notes under the slides. Download the PowerPoint presentation.

  Notes: This will download the PowerPoint presentation to your computer. You will need Microsoft PowerPoint to open/see the presentation. If you are having trouble, sometimes it is best to select the option 'Save file' when prompted, open powerpoint, and then open the downloaded file (Webtop10.ppt). In our tests, both Firefox and MS Internet Explorer browsers running on a Windows XP machine and the latest version of Microsoft Office had no problem downloading and viewing the file. The file size is 2.78 MB. The full file path is http://cheec.uiowa.edu//sites/cheec.uiowa.edu/files/Webtop10.ppt.

• Radon: What you can't see can hurt you. An article appearing in the fall 2005 edition of Spectator, a University of Iowa Publication. The link will download a PDF document.

Acknowledgements: We thank the National Institutes of Health: National Cancer Institute and National Institute of Environmental Health Sciences , Center for Health Effects of Environmental Contamination at the University of Iowa, Iowa Cancer Registry, and the participants and their caring families that made these studies possible.

In 1986 the Iowa General Assembly passed House File 2303. This legislation mandated that the Iowa Department of Natural Resources (IDNR) must develop and implement a one-time analytical testing of the finished water from Iowa's publicly and privately owned water systems for 35 pesticide compounds and 35 volatile organic contaminants (VOC). The University Hygienic Laboratory (UHL) provided all analytical services to this program which ran from November 1986 to November 1987.

Eight hundred and fifty-six public water systems were tested. One hundred and twenty-five tested positive for one or more pesticides. Five hundred and fifty tested positive for one or more synthetic organic compounds. No measurable concentrations of pesticides or volatile organic chemicals were found in 279 systems. A few water systems had pesticides or volatile organic chemical levels that exceeded U.S. Environmental Protection Agency health advisories or maximum contaminant levels, but contaminant levels high enough to cause an acute health risk were not observed in this study.

The pesticides most commonly found were atrazine, cyanazine (Bladex), alachlor (Lasso), metolachlor (Dual), and 2,4-D. The most frequently found volatile organic chemicals belong to a group called trihalomethanes (THMs). THMs are formed during disinfection when chlorine reacts with organic matter in the water. Para- and meta-xylene, measured as a single compound, was the second most abundant VOC observed.

The following are the most significant findings of this one time testing:

• Surface water systems have the greatest potential for pesticide contamination.
• The shallower ground water sources have a greater potential for contamination by pesticides and VOCs.
• A seasonal trend in pesticide occurrences in water sources was not observed, with the exception of 2,4-D found at low levels.
• The frequency of appearance and concentration of trihalomethanes in ground water systems serving small municipalities was unexpected.

For a copy of this report, contact the University Hygienic Laboratory at (319) 335-4500.

Breast and thyroid cancers pose an increasing health threat to young adult women ages 20-39 years in the United States (U.S.). Analysis of cancer surveillance data for the years 1992-2011 from 13 U.S. Surveillance, Epidemiology, and End Results (SEER) Cancer Registries identified that the annual incidence of Stage I-III hormone receptor-positive breast cancer among women ages 20-29 years and 30-39 years in Iowa, ranked second and fourth, respectively among the 13 registries. A recent review of Iowa SEER Cancer Registry data identified that the incidence of thyroid cancer has increased markedly from 1974-1983 to 2004-2013 among Iowa women ages 25-39 years. Even with this changing epidemiology, risk factors that contribute to these premenopausal malignancies are not well studied. Moreover, factors examined for postmenopausal breast and thyroid cancers do not seem to explain their increased incidence among premenopausal women. Because premenopausal breast and thyroid cancers are often hormonally mediated, their onset may be influenced by exposure to endocrine disrupting chemicals (EDCs), and such exposure could begin prenatally. To date, investigation of prenatal exposures and premenopausal breast and thyroid cancers is limited, and investigation of both prenatal and postnatal exposures is largely unexplored. As such, we propose to take full advantage of the high-quality, population-based cancer surveillance data collected by the Iowa SEER Cancer Registry and the multi-decade repository of population-based birth and death data maintained by the Iowa Registry for Congenital and Inherited Disorders to examine prenatal and postnatal exposures in the etiology of breast and thyroid cancers among a cohort of young adult Iowa women. We hypothesize that breast cancer and thyroid cancer in young adult Iowa women have geospatial predilections, suggesting estrogenic environmental risks from birth to diagnosis. For breast cancer, we also hypothesize that differences in endogenous hormone exposure are positively associated with increased incidence and worse outcomes for young adult women with hormone receptor-positive than those with hormone receptor-negative disease. To test these hypotheses, we aim to: 1) link cancer surveillance data with birth and death data to establish and describe a cohort of young adult Iowa women with breast or thyroid cancer; 2) conduct individual-level geospatial surveillance for young adult Iowa women with breast or thyroid cancer; and 3) examine associations between selected environmental exposures at birth and at diagnosis and development of breast or thyroid cancer in young adult Iowa women. In conducting these aims, we will eschew more traditional study designs, and instead, implement a population-based, life course, household-level design. Our proposed design also will allow us to easily incorporate annual updates of cancer surveillance and birth and death data to monitor future patterns of cancer occurrence and emerging exposures in this cohort. Elucidating etiologies of breast and thyroid cancers in young adult women is critical due to the prevalence of these diseases, as well as the marked personal and societal impacts of cancer diagnosis at a young age. Our study can help provide insights into these etiologies, an important step to developing interventions to reduce the incidence of these malignancies in young adult women.

Naturally-occurring radioactive material can be a substantial source of radiation exposure to the public, especially in ground-derived drinking water. Two radionuclides from the uranium decay series (lead-210; Pb-210 and polonium-210; Po-210) are of particular concern because their characteristic properties combine to present potential carcinogenic risks to human. These radionuclides are present in subsurface geological deposits where a great deal of drinking water in the state of Iowa is derived. While the potential carcinogenicities are known, concentrations of Pb-210 and Po-210 are not well characterized in Iowa aquifers. This study proposes to determine the concentrations of Pb-210 and Po-210 in 50 privately-owned wells across the state to develop an understanding of the potential contribution to increased lifetime cancer risk to Iowans.It is expected that success in these studies will result in a more detailed understanding of the biogeochemical relationship of increased levels of Po-210 and Pb-210 to other natural radionuclides found in Iowa's well water, and will provide preliminary data for understanding potential risk of natural radioactivity in Iowa's well water.

Approximately 1/3 of the world’s population lacks access to safe drinking water. Human exposures to drinking water contaminants, such as arsenic, have been linked to cancer, neurological, cardiovascular and pulmonary health problems. In a recent survey of private wells in Iowa, 48% were found to contain arsenic and 8% were determined to have arsenic levels greater than the EPA’s drinking water standard of 10 ppb. It is critical, both globally and locally, to develop improved methods for removing groundwater contaminants. Investigators in this study will design, fabricate and evaluate mesoporous silica-coated electrospun iron oxide nanofibers for arsenic adsorption from water. The Larsen Lab is developing functionalized mesoporous silica materials for adsorption of radioactive contaminants; these materials are also promising for application as arsenic adsorbents. The Cwiertny/Parkin Lab is developing electrospun nanofibers for use as chemically active filtration materials. CHEEC funds will allow the two Labs to work collaboratively to develop and evaluate these novel composite adsorbents.

Wireless telephone use, caller ID, and call blocking pose challenges to telephone-based data collection for epidemiological studies; smartphones, tablets, and increased access to the internet have removed both time and place demands of home-based communications. Telephone-based data collection in Iowa for the NBDPS has indicated a steady decline in participation rates. This case-control study will evaluate a web-based approach for molecular environmental epidemiological studies of adverse pregnancy outcomes. 240 infants with selected birth defects and 240 infants without defects will be selected and equally assigned to a web-based or a telephone-based group. They will be administered a questionnaire for maternal environmental exposures; mothers in the web-based group will electronically sign a consent form to use residual newborn bloodspots for biomonitoring; for the telephone-based group, the U.S. Postal Service will be used for hand-signed informed consents. Participation rates, sample representativeness, exposure reporting, and costs between the web-based and telephone-based groups will be compared. Investigators hypothesize that improved participation rates will be seen in the web-based group, which will permit increased generalization of study results and increased statistical power for studies.

Arsenic is an emerging water quality issue in Iowa’s groundwater. According to the Iowa Department of Natural Resources, there are 69 public water supplies that utilize groundwater with arsenic concentrations greater than the recommended limit and in as recent survey of 473 private wells in Iowa, 48% were found to contain arsenic. This study will help address the issue of arsenic in groundwater by conducting laboratory experiments to better understand the geochemical processes controlling the release of arsenic from soils to groundwater. This project will build on previous work that developed analytical methods for measuring arsenic and investigating the reduction of arsenic by common soil minerals. The objectives of this study are to 1) determine the extent of arsenic incorporation and release from iron minerals commonly found in Iowa aquifers, and 2) measure the release of iron and arsenic from Iowa aquifer materials where arsenic has been identified in the groundwater.

Biosolids are generally defined as the end-product of production and treatment of sludges generated during wastewater treatment. Beneficial uses of biosolids (e.g., land application, landfill covers, etc.) are expected to increase in the coming years. Wastewaters from domestic and industrial sources are known to contain relatively low concentrations of endocrine disruptors, antibiotics and pharmaceuticals. Most of what is known about the fate of these compounds comes from measurements taken before and after treatment of the liquid component of the wastewater. Very little is known about the fate of these compounds during processing of the solids generated during wastewater treatment. Many of these compounds are likely to partition onto particulate matter due to their hydrophobic nature. Thus, it is important to understand the fate of these compounds during the production and use of biosolids. Aqueous samples collected at points throughout a wastewater treatment plant were processed and analyzed for acetaminophen, caffeine, cotinine, ibuprofen, 4-nonylphenol, sulfamethoxazole, triclosan, and trimethoprim. Most aqueous phase removal occurred during primary clarification and/or activated sludge treatment while little or no aqueous phase removal resulted from secondary clarification or chlorination/dechlorination. Sorption isotherms determined for each compound on biosolids from the plant indicated compound specific sorption behavior. Caffeine, cotinine and acetaminophen were significantly removed from the aqueous phase during activated sludge treatment. This implicates biotransformation as a primary removal process given the low sorption potential of these chemicals. Sulfamethoxazole and trimethoprim also have low sorption potential, but are more chemically stabile such that only a small quantity of each was removed during activated sludge treatment. Ibuprofen, 4-nonylphenol and triclosan were significantly removed from the aqueous phase during activated sludge treatment, likely as a result of sorption processes as evidenced by high log Kow values and high concentrations of triclosan and 4-nonylphenol in analyzed biosolids.

Conducted from June 2002-January 2003, the study aimed to achieve a better understanding of private drinking water wells in incorporated Iowa towns not served by a public water supply system. Water samples were analyzed by the University of Iowa Hygienic Laboratory (duplicate samples analyzed at USGS laboratories) for common use pesticides, nitrogen compounds, inorganics, bacteria, and VOCs. The study design contained a random and focused component. * Random Study Methodology: Approximately 103 drinking water wells from towns that did not have a public water supply were selected. A weighted distribution of households from US Census data was employed to select wells (i.e.- towns with a higher number of households stood a greater chance of having a well selected). County environmental health specialists visited these towns, located randomly generated points on maps, and found the nearest building to draw a water sample. Fifty distinct towns had one or more wells sampled. * Focus Study Methodology: The focus study employed the use of existing databases of potential contamination sources to intensively sample 15 communities. Selection criteria for these towns considered: towns utilizing private septic systems, existence of underground storage tanks, location of agricultural grain and chemical storage dealerships, regional hydrogeology, active and closed landfills, feedlots, railroad systems, industries in violation of wastewater permit applications (including stormwater permits), nearby uncontrolled sites identified by the Iowa Department of Natural Resources (IDNR), and Resource Conservation and Recovery Act (RCRA)/Superfund sites. 

Researcher teams at IIHR – Hydroscience & Engineering propose to develop new drone-based technology for water quality measurements, in collaboration with Iowa Lakeside Laboratory, to provide rapid and high-resolution detection of potentially harmful algal blooms (HABs) in Iowa lakes and reservoirs. We will develop a tool that combines remote sensing cameras and unmanned aircraft systems (UAS) to conduct on-demand and rapid sampling of water quality without the need for chemical water testing. This pilot study will utilize infrared and multispectral camera instruments mounted on a heavy payload octocopter UAS or drone, which was developed and operated by Markfort's Environmental Fluid Mechanics and Renewable Energy lab to characterize atmospheric boundary layer winds and terrestrial surface properties including vegetation, to detect HABs.

Harmful algal blooms (HABs) caused by cyanobacteria are a serious environmental problem in natural water. Exposure to cyanobacteria metabolites can lead to human poisoning and animal mortality. The proposed study will focus on investigating the major HAB species in Iowa by analyzing samples from the current State Beach Monitoring Program. Microcystin positive environmental samples will be used for isolate cultivation and strain library construction. A unique mass spectrometry platform, so called Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS), will be used to develop a rapid strain identification assay. This integrated approach will help determine the major cyanobacteria species that lead to algal blooms in Iowa and establish a cyanobacteria library for rapid species identification. The constructed cyanobacterial library will be shared resources for the research community. Findings from this study will help facilitate environmental risk management and develop mitigation strategies to reduce human and animal health risk.

Neonicotinoids represent one of the most heavily used pesticide classes, particularly for corn and soy production. Despite their ubiquity in Midwestern water resources, little is known about their fate in the environment, particularly engineered treatment systems intended to mitigate risk their exposure. This work is motivated by our overriding hypothesis that chemical and biological processes used in conventional treatment alter the structure of neonicotinoids so as to remove their specificity to invertebrates, thereby exposing non-target organisms, including humans, to unanticipated risks arising from their bioactive transformation products in finished water and effluent. Our research plan integrates laboratory studies simulating conventional water and wastewater treatment processes with monitoring of neonicotinoid removal and transformation at the University of Iowa Water Treatment Plant. Outcomes will provide the first insights into best practices for neonicotinoid removal during treatment and better understanding of the risks associated with their formation of unintended transformation byproducts.

The aquatic environment can act as a reservoir for antibiotic resistance genes (ARGs) and therefore contribute to human health risk. Effluent discharges from wastewater treatment plants (WWTPs) provide a constant and significant point source of environmental ARGs even in agricultural areas like Iowa. As the first step towards accurate risk assessment of the environmental dissemination of antibiotic resistance, a predictive and quantitative model of ARG persistence in Iowa rivers will be constructed and evaluated. The tasks of the proposed work involve constructing and evaluating a model that accounts for physical, chemical, and biological mechanisms of fate and transport of ARGs. Modeling will start with mass balances applied to the water column, suspended particles, sediment bed, and biofilms. The model will be evaluated by comparing with measurements in controlled laboratory microcosms and field measurements in the Ames, IA WWTP and its receiving river.

Antimicrobial resistance is a serious threat to both animals and humans. The large number of farm animals receiving antibiotics and their close contact with soil and water resources pose a public threat to the increasing emergence of antimicrobial resistance and ineffective drug treatments. Consequently, methods to mitigate the transport and spread of antimicrobial resistance are critically needed. Prairie strips are a conservation practice that uses strategically placed native prairie plantings in crop fields and have been shown to reduce the movement of soil and water from the agricultural environment. The study hypothesis is that prairie strips can also mitigate the spread of antimicrobial resistance genes and bacteria to the environment. This project develops a pilot system to test the retention of manure-associated resistance genes and bacteria in installed prairie strips and evaluates its benefits for surrounding soils and   waters. 

Photocatalysts, such as TiO2, can be used to degrade a wide range of organic contaminants found in polluted air. TiO2 photocatalysts are active at ambient temperatures and pressures in the presence of UV irradiation and oxygen and have been shown to oxidize toluene, trichloroethylene (TCE), methanol/ethanol and many other organic compounds. In this proposal, solid state MAS NMR (magic angle spinning nuclear magnetic resonance) techniques will be utilized to identify surface species formed during heterogeneous photocatalytic oxidation reactions on TiO2. These surface species may be reaction intermediates, surface poisons or partial oxidation products. Spectroscopic studies of TCE enhancement of toluene photooxidation will be conducted to determine the origin of the enhancement for deactivation. The proposed research will provide insight into the role of surface species in photocatalytic oxidation reactions on TiO2 that could lead to the development of improved photocatalysts.

This seed project spans two interdisciplinary collaborations across the College of Engineering, and College of Public Health that harness the power of information science and signal processing towards better understanding of contaminant fingerprints in the environment. In particular, the PI will investigate data-driven associations linking contaminant clusters to environmental, geographic and social drivers. This project will develop a data-driven infrastructure towards robust interpretation of raw signal and processed field  data, along with prediction models for success of intervention methods. While the focus of the work is chemical contaminants, the methods here apply equally to biological contaminants, e.g. water-borne fecal pathogens in soil and water. 

Neonicotinoids represent one of the most heavily used pesticide classes, particularly for corn and soy production. Despite their ubiquity in Midwestern water resources, little is known about their fate in the environment, particularly engineered treatment systems intended to mitigate risks of their exposure. This work is motivated by an overriding hypothesis that chemical and biological processes used in conventional treatment alter the structure of neonicotinoids so as to remove their specificity to invertebrates, thereby exposing non-target organisms, including humans, to unanticipated risks arising from their bioactive transformation products in finished water and effluent. Theresearch plan integrates  laboratory studies  simulating conventional  water and wastewater treatment processes with monitoring of neonicotinoid removal and transformation at the University of Iowa Water Treatment Plant. Outcomes will provide the first insights into best practices for neonicotinoid removal during treatment and better understanding of the risks associated with their formation of unintended transformation byproducts.

Increasing levels of antibiotic resistance in clinical settings has led many to believe that animal agriculture antibiotic use is contributing to the global resistance problem; however, that connection is unclear given the limited understanding of antibiotic resistant bacteria (ARB) and resistant genes (ARG) in the soil and water environment. Our previous work has documented differences in ARG concentrations in drainage when compared to measured concentrations of U.S. EPA recommended indicator bacteria. Here, we propose laboratory experiments in a controlled column environment, representative of an agroecosystem, to (1) identify the diversity and quantify the abundance of ARGs and their hosts in manure, soils with varying management histories, and simulated subsurface drainage; and (2) identify the diversity and quantify the abundance of mobile genetic elements and their linkages to ARGs. Results will provide valuable insight into i) the microbial community harboring ARGs and ii) horizontal gene transfer processes occurring in agricultural systems.

Fresh water cyanobacteria harmful algal blooms (HABs) are increasing in frequency and severity in the U.S. and globally. Blooms produce potent and lethal cyanotoxins which poison people and animals. This is a serious emerging “One Health” problem. Among the many cyanotoxins produced by HABs are hepatotoxic and carcinogenic microcystins. Currently, the state-of-the-art diagnostic approach for microcystin intoxications in people is measuring elevated blood serum liver enzymes as biomarkers of effect. Unfortunately, elevated liver enzymes are late biomarkers of microcystin effects. The objective of this study is to identify and characterize early biomarkers of microcystin exposure and effects in humans using the mouse model. These early biomarkers will be used for diagnosis in populations exposed to contaminated water in order to mount early intervention procedures to protect individual and public health.

Organophosphate (OP) and carbamate pesticides are widely used in agriculture. Acute exposure to high doses may cause cholinergic toxicity; however, recent work demonstrates that exposure to low levels causes adverse effects in humans from neurological deficits to oxidative stress/reactive oxygen species (ROS). The mechanism for this “non-canonical” toxicity is unknown but concerning given the ubiquitous nature of OP and carbamates in the environment and significant human exposure. Such adverse consequences are likely due to effects of these pesticides on cell types found in the brain other than cholinergic neurons, such as other neurons or glial cells (non-neuronal). The goal of this project is to determine which neuron types (i.e., cholinergic, glutamatergic, dopaminergic) or non-neuronal cells (i.e., astrocyte) are most sensitive to OP and carbamate pesticides, yielding toxicity and/or oxidative stress/ROS. In addition, the investigator seeks to identify the insulting species of the OP agent, i.e., phosphorothioate or bioactive oxon metabolite.

Contaminants of emerging concern (CECs, unregulated compounds including pharmaceuticals and personal care products) are ubiquitous in environmental and drinking waters, posing potential risks to human and ecosystem health. This proof-of-concept study will characterize the transport and fate of CECs in a stream reach using a suite of tracers with well-characterized, complementary reactivities. Specific research tasks include quantifying reaction pathways within the environmental system, laboratory experiments linking tracer and CEC reaction rates, and numerical modeling to predict transport and fate of CECs. The overall goal of this research is to quantify reaction pathways in the environment and successfully predict the transport and fate of CECs. A major outcome will be a mechanistic understanding of transport and fate processes that can be applied to any CEC in the system; this will enable prediction of the spatial extent and temporal persistence of CECs in streams.

While glyphosate, the ingredient present in the widely used RoundUp® family of herbicides, has an excellent safety profile following topical and oral exposure, it presents a potential CNS exposure risk if it is able to access the olfactory transfer pathways within the nasal mucosa. These pathways afford the opportunity for molecules to access the brain without needing to cross the blood-brain barrier. This pilot study will evaluate whether glyphosate and several commercial glyphosate herbicide formulations are able to permeate through the olfactory mucosa into the olfactory bulb and nearby brain regions following direct nasal instillation and aerosol exposure. Preliminary results will provide initial quantitative evidence regarding the risk of CNS glyphosate exposure following nasal inhalation and will support further investigations to evaluate the exposure risk along with identifying methods to limit inhalation exposure to herbicide applicators or those in close proximity to spraying operations.     

Carbon nanotubes (CNTs) are engineered nanoparticles (<100 nm) that have been shown to cause adverse pulmonary outcomes in test animals. As such, the National Institute for Occupational Safety and Health (NIOSH) is considering a recommended exposure level (REL) for CNTs of 7 µg/m3, which is the limit of quantification (LOQ) of a method used to measure elemental carbon (EC) in diesel particles. Such a limit presents either an under- or over-exposure scenario with no information to determine actual conditions when below the LOQ. This pilot project will seek to establish a relationship between CNT particle count concentrations given known size distributions and EC mass concentrations to guide the interpretation of environments that may become contaminated with CNTs below the LOQ. A secondary objective will be to compare EC concentrations measured using the NIOSH method with those obtained from a hand-held device suitable for personal exposure assessments.

The attachment of agricultural Escherichia coli isolates to environmental particles is significantly associated with multi-drug resistance. This association motivates our hypothesis that the genes responsible for bacterial attachment are encoded on a mobile genetic element that also encodes resistance and virulence. These mobile genetic elements are a group of transferable genes that can pass from one bacterium to another; plasmids are the most common form. Here, gene transfer confers not only resistance but possibly virulence. Thus, these genes are a possible environmental contaminant that could threaten human health. In this pilot-scale work we will first confirm that the genes encoding resistance and attachment can be co-transferred between bacteria. This would validate these genes as environmental contaminants. We will then sequence any plasmids transferred between bacteria during the transference of resistance and attachment. This would identify any virulence-associated genes, providing information about the threat that these plasmids present to human health.

The  pesticide  chlordane  is  a  mixture  of  structurally  related,  highly chlorinated hydrocarbons and is a persistent environmental contaminant linked to a range of adverse health effects in animals. Most of the isomers are chiral, and may be metabolized in an enantiospecific manner. This type of metabolism has been shown for other chiral pollutants. We hypothesize that chiral chlordane isomers are metabolized enantioselectively by cytochrome P450 enzymes. To test this hypothesis we will take advantage of  a knockout mouse model lacking the  NADPH-dependent cytochrome P450 reductase, a critical enzyme in the catalytic cycle of P450 oxidation, and measure levels and enantiomeric fractions of chlordane and its metabolites in tissue from wild- type and knockout mice. This research will provide key mechanistic information about enantiospecific metabolism of chlordane, and can be extended to other pesticides commonly found in Iowa.

Endometriosis is a chronic disease affecting ~15% of US reproductive-aged women, and is a significant cause of infertility. One suggested risk factor is exposure to organochlorines (OC). Diagnosed cases of endometriosis have been detected with longer exposure or higher serum concentrations than controls for OCs (PCDD, PCDF, and PCB/dioxin); however, study results have been inconsistent due partly to small numbers of cases/controls and limited exposure history. Analyses using the Agricultural Health Study will provide a significantly larger sample size for a case-control study and detailed measures of pesticide and environmental exposure to common agricultural pesticides and to these OCs. Study results will be used as pilot data for an National Institute of Child Health & Human Development (NICHD) proposal of clinic-based case-control study. In 2010, an NICHD Fertility Preservation Research Program, sought grants to characterize occupational and environmental exposures that may be associated with risks of infertility. This exposure and infertility issue continues to be of interest to NICHD. 

This pilot project will analyze the growth inhibiting effects of the herbicide metolachlor on non-target, human HepG2 cells. Metolachlor, a very commonly used herbicide in the United States, especially in the Midwest corn-belt, functions by inhibiting chlorophyll and protein synthesis in target plants. Herbicide exposure has led to detrimental effects in several organisms, notably affecting their growth and behavior, however, its mechanism of action in non-target organisms is not yet clear. The EPA does not currently have specific regulations for maximal limits allowed in drinking water. Growth studies from our lab demonstrate that increasing metolachlor concentrations and increasing time of exposure results in decreased growth of liver cells. The objective of this study is to elucidate a mechanism for decreased HepG2 cell growth after metolachlor exposure. Analyses will include assessing toxicity effects leading to necrosis, effects of apoptosis induction and alterations in cell cycle progression

A large amount of epidemiological and experimental studies indicate that particulate matter (PM), including, ultrafine particles, have close association with many respiratory and cardiovascular diseases. PM is a complex mixture of organic and inorganic airborne substance, generally composed of a core of ash or carbon, which is coated with organic molecules and transition metals of a broad size range. Between all the transition metals in PM composition, iron is almost always the most abundant in urban and rural areas. As a transition metal, iron is capable of generating reactive oxygen species (ROS) and contributing to oxidative stress, especially in the alveolar epithelium. Oxidative damage and cell death in the alveolar epithelium are the principal mechanisms attributed to PM and asbestos-induced lung injury. We hypothesize that iron content increases the expression of ferritin in alveolar epithelial cells (AEC), which in turn activates p53- dependent cell death pathway.

Environmental toxins, such as the herbicide paraquat, can cause damage to cells by inducing oxidative stress. 4-hydroxynonenal (4HNE) is the major lipid peroxidation product of oxidative stress and is highly reactive toward protein cysteine residues. RGS4 is a member of the Regulator of G protein signaling (RGS) protein family, and contains a cysteine residue (Cys148) that is sensitive to covalent modification, which irreversibly inhibits its function. RGS proteins are signaling checkpoints downstream of G protein coupled receptor (GPCR) activation and are critical for regulating the magnitude and duration of GPCR-mediated cell signaling events. We hypothesize that this sensitive site on RGS4 (Cys148) is modified during oxidative stress by 4HNE, thus inhibiting RGS4 function. As alterations in GPCR signaling and RGS protein function are evident in neurodegenerative diseases such as Parkinson’s, this proposal seeks to define the role of oxidative stress and 4HNE in RGS4 inhibition and subsequent cellular signaling dysfunction.

Polychlorinated biphenyls (PCBs) are a group of industrial chemicals that persist in the environment and cause adverse neurodevelopmental effects (such as altered brain ryanodine binding) in laboratory animals and in humans. Several neurotoxic PCB congeners, such as PCB 136, are chiral and, as we have shown recently, sensitize ryanodine receptors in an enantiospecific manner in vitro. We hypothesize that exposure to PCB 136 during gestation and lactation causes long-term neurodevelopmental effects in an enantiomer specific manner, with (-)-PCB 136 being more potent and efficacious than (+)-PCB 136. This hypothesis will be tested by investigating enantiomer specific differences (1) in the profile of PCB 136 and its metabolites and (2) brain ryanodine binding in mice exposed during gestation and lactation to (+)- and (-)-PCB 136.

Polychlorinated biphenyls (PCBs) are toxic, carcinogenic, and bioaccumulative compounds that are often found in lake and river soils and sediments. PCBs in soils and sediments represent a human health risk, especially if natural processes promote PCB volatilization and subsequent exposure to humans. Biodegradation of PCBs would reduce the risk of adverse human health effects, but this process is poorly understood in sediments. The objective of this research is to test the hypothesis that aerobic, PCB-degrading bacteria are present and active in PCB-contaminated sediments from Indiana Harbor. Preliminary studies revealed aerobic PCB biodegradation potential, but additional experiments are needed to determine if PCB-degraders are active in these sediments. An array of experimental approaches, some of which are innovative, involving reverse-transcription (RT)-PCR, real-time RT-PCR, proteomics, and metabolite analysis are proposed.

Fecal contamination of water is a significant public health concern. The primary objective of this proposal is to determine the usefulness of adenovirus as an indicator of fecal contamination and its potential for fecal sourcetracking. This objective will be addressed by the following aims: (1) to improve upon and validate a PCR algorithm to detect human and animal adenoviruses in fecal waste and water, (2) to conduct surveys of adenoviruses in cattle and swine stool in order to determine the usefulness of adenovirus as a source-tracking organism, and (3) to estimate the prevalence of human and animal adenoviruses at impaired and transitional Iowa beaches and to identify parameters associated with adenovirus in surface water. Results from this study will be used to further develop rapid methods to detect adenoviruses in water and accurately identify sources of contamination which would be informative to risk assessment and risk management practices. Technical Report Available.

The Agricultural Health Study (AHS) associated exposure to certain pesticides with increased prostate cancer risk in individuals with a first-degree family history of prostate cancer. These findings indicate that exposure to these environmental contaminants may interact with a genetic predisposition toward prostate cancer, but the biologic mechanism(s) by which this might occur remain unclear. This information is critical not only for better defining the risks posed by these pesticides for farm workers and others exposed to these chemicals, but also may advance our understanding of prostate cancer progression in the general population. Experimental exploration of the mechanistic links between pesticide exposure and prostate cancer progression will be difficult in humans. Therefore, the objective of this proposal is to test whether exposure to organophosphorothioates accelerates prostate cancer progression in a mouse model genetically predisposed to develop premalignant prostate lesions (B6:PTEN/luc) in order to establish an experimental platform for exploring these links.

The rapid growth and development in the synthesis of nanomaterials with carefully controlled properties, such as size and shape, surface area and composition has led to a burgeoning of potential applications for these nanomaterials. However, the toxicological effects of these materials such as nanocrystalline zeolites have not yet been systematically investigated and assessed with respect to their properties. In this proposal, the impact of size, surface chemistry, composition and porosity of nanocrystalline zeolites on the mechanism of death in lung epithelial cells will be investigated.

It is hypothesized that metal oxides may exist in some drinking water distribution systems capable of oxidizing iodide and possibly bromide producing species that can react with natural organic to form halo-organic compounds of possible health concerns. This hypothesis is based on recently obtained experimental evidence indicating that lead oxide (PbO2), an oxide that can accumulate in distribution systems and on household plumbing fixtures, has the capacity to oxidize iodide. The primary objectives of this research are to demonstrate proof-of-concept of this novel reaction pathway, and to investigate factors that influence the extent and rates of the reactions. Studies will initially focus on the lead oxide-iodide-NOM system and measurement of selected iodo-organic compounds. Additional studies will be conducted using several other oxides. If iodide is found reactive, then oxidation of bromide will also be evaluated to determine if formation of bromo-organic compounds is also possible at environmentally relevant conditions.

The purpose of this pilot project is to evaluate the effectiveness of water treatment in removing fragrance compounds from drinking water. Synthetic musk fragrances are common additives to many household products. They have been found in wastewater effluent discharge and are considered to be common contaminants in surface waters. The effectiveness of conventional water treatment at removing synthetic fragrances is not well known. Some evidence suggests that removal efficiencies are very poor. This is of concern because many synthetic musk fragrances are endocrine disruptors and may present a health risk to humans. The objectives of this pilot project include: 1) Weekly monitoring at the University of Iowa Water Plant: 2) Determination of removal efficiency; and 3) Evaluation of specific treatment processes.

We propose to develop an advanced instrument capable of determining the aerodynamic size, approximate shape, and detailed chemical composition of single bioaerosol particles sampled directly from the ambient atmosphere. The correlated data will be used to classify individual particles and provide a detailed characterization of diverse aerosol populations. Sample preparation will be minimal and the analysis sufficiently rapid that identification can be achieved in near real-time. The experimental methodology will integrate advanced solid-state laser sources and mass spectrometric techniques to fashion a powerful and unique instrument. The resultant device will be used in projects to characterize bioaerosols present in the environment, such as in agricultural workplaces, provide a sensitive detection capability for possible biohazards, and monitor bioaerosol transformations induced by chemical processing in the atmosphere. The capabilities of the proposed instrumentation would greatly facilitate epidemiological studies which seek to correlate bioaerosol exposure with deleterious health effects. Technical Report Available.

This proposal describes the development of a personal exposure screening tool for prediction of gas- and aerosol-phase vehicular air toxics. The tool will marry existing approaches for gaseous pollutants together with emerging techniques and data for size-resolved fine, ultrafine, and nanoscale particulate matter (mainly from diesel exhaust). Including size-resolved particulate matter in a screening model is a significant challenge, made necessary because of the recent focus on the relationships between traffic, health effects, and ultrafine/nanoparticle toxicity. Further rationale for including size resolution comes from upcoming EPA-mandated changes to diesel sources. Emphasis will be placed on creating an efficient model for general and screening use, rather than a highly detailed model for application to a specific location or exposure setting. It is anticipated that the work product will be well received by funding agencies, public health researchers, and transportation planners.

Adverse health outcomes have been associated with exposure to atmospheric particulate matter (PM). National Ambient Air Quality Standards aim to protect Americans from these exposures through state-run monitoring networks; states must reduce particle concentrations when they exceed national standards. Costs associated with traditional samplers severely limit the number of monitoring sites, which hampers efforts to identify and control key sources of particles. The work proposed here will adapt a new passive sampler for its use in PM networks via three tasks: [i] design an outdoor housing for the new sampler; [ii] assess its precision and accuracy for concentrations typical of the atmosphere; and [iii] use these samplers to identify any key sources of particulate within Iowa City. Passive samplers are substantially more economical than traditional samplers; thus, this work will enable more observations so that actions taken by states to reduce particle concentrations will have a greater likelihood of success.  

Zeolites are crystalline, aluminosilicate molecular sieves with pores of molecular dimensions that are widely used as catalysts, adsorbents and ion exchangers. Nanocrystalline zeolites are synthetic zeolites with discrete, uniform crystals of less than 100 nm in size. Nanocrystalline zeolites have increased surface areas relative to commercial, micron-sized zeolites. In our laboratory, we have synthesized several different zeolites (ZSM-5, Y and silicalite) with crystal sizes of approximately 20 nm. These materials have enhanced adsorption capacities due to the increased surface areas relative to micron-sized zeolites. The nanocrystalline zeolite external surface can be functionalized to tailor its properties for adsorption of pollutants in different environments. The hypothesis of the proposed study is that nanocrystalline zeolites will be effective adsorbents for volatile organic compounds (formaldehyde, benzene and trichloroethylene) and inorganic oxyanions (chromate, arsenate, selenate). These environmental pollutants have been linked to many health problems due to their toxicity.   

Perchlorate has been linked with thyroid dysfunction in humans and thus represents a serious potential health risk. Prior research on perchlorate remediation has shown that (1) perchlorate-degrading bacteria are present in nature but are often electron donor limited; (2) plants release electron donors and carbon sources into soil; (3) perchlorate-degrading bacteria require low redox potential to reduce perchlorate; and (4) plants raise redox potential in the subsurface. These findings are somewhat contradictory and may impact perchlorate remediation schemes. We propose to study the relationship between plants and bacteria to determine whether the integrated effect of plants on bacteria is synergistic or antagonistic, whether the release of electron donor and carbon by plants is sufficient to overcome the inhibition to bacterial perchlorate reduction caused by the higher redox potential. Our focus is on higher concentrations of perchlorate (>25mg/L) because we believe it is important to control contamination at its source to effectively reduce health risks.

The recent explosive epidemic of avian influenza in Asia has many public health officials concerned. Iowans have numerous occupational and recreational exposures to avian species that might cause them to be infected with avian influenza viruses, yet they have never been studied. We propose a pilot seroprevalence study of 250 Iowans with exposure to ducks, geese, and game birds to investigate such transmission. After informed consent is obtained, DNR workers, hunters, and others with game bird exposure will be asked to complete a risk factor questionnaire, and to permit the collection of at least one serum sample. We will also collect cloacal or tracheal samples from 390 of their birds. Human serological testing and bird viral cultures will be performed to document Iowans at high risk of avian influenza virus infection. Identifying high-risk individuals and their exposures is a first step towards developing public health interventions to protect against such future infections.

Meat processing workers are often exposed to various avian, swine, and bovine tissues. It is hypothesized that due to these exposures meat processing workers may have elevated risks for acquiring a number of zoonotic infections. This pilot investigation will focus upon three organisms: West Nile virus, influenza A virus, and avian pneumovirus. The study design involves the collaboration of two meat (pork, turkey, chicken, and beef) processing plants in Iowa. One hundred meat processing employees from each site along with their spouses (n~400 subjects) will be enrolled. Serum would be studied for evidence of infection with the three viral agents of interest. Seroprevalence data from the workers at the two plants will be compared with their spouses to discern evidence of occupational risk. This pilot study may shed significant light upon previously unexamined environmental health risks for meat processing workers in Iowa and throughout the United States.

Perfluorinated surfactants such as N-methyl perfluorooctane sulfonamidoethanol (NMeFOSE) are produced for a large number of applications such as fire fighting foams and furniture coatings. These chemicals are emerging as an important class of environmentally persistent chemicals. Our knowledge of their metabolism, distribution, disposition and, ultimately, mechanisms of toxicity is very limited. Exposure to these chemicals has been associated with developmental toxicity in several animal models. This research hypothesizes is that after uptake with the diet, NMeFOSE is metabolized in vivo to perfluorooctane sulfonic acid. Studies aims are (1) to synthesize putative perfluorooctane sulfonyl metabolites (2) establish analytical assays to measure NMeFOSE and its metabolites in biological samples, (3) study the in vitro metabolism of NMeFOSE with rat liver microsomes, and (4) measure the distribution of NMeFOSE and its metabolites in female rats.

Tylosin is a veterinary antibiotic commonly used in swine production for growth promotion and disease prevention. Swine excrete this drug in urine and feces, and tylosin enters the environment via manure application. This study proposes to investigate the mobility and degradation of tylosin, as well as the survival and movement of microorganisms in the presence of tylosin. Waters leaching from intact soil columns will be examined for tylosin, for total Escherichia coli and for tylosin-resistant E. coli. Following the completion of the study, soil will be evaluated for the mobility of tylosin and presence of metabolites, as well as for survival and movement of microorganisms. The experimental design will allow us to determine if tylosin causes increased levels of tylosin-resistant E. coli in soil or if tylosin increases survival and movement of tylosin-resistant E. coli in manure.

Until recently it was believed that the occurrence of nitroso compounds in drinking water and wastewater was due to contamination of the source water. Recent observations indicate that N-nitrosodimethylamine (NDMA), a particularly potent carcinogen, can be produced during water and wastewater treatment. Studies at Iowa have recently elucidated a novel formation pathway that involves reactions of chlorine, ammonia, and dimethylamine that support the hypothesis that NDMA is a new disinfectant by-product (DBP). We propose that NDMA is but one representative of a new class of disinfectant by-products, the nitroso compounds, many of which are of health concern. We hypothesize that other types of nitroso compounds are also formed by a similar mechanism in chlorinated and chloraminated drinking and waster. This project will investigate the formation mechanism and occurrence of several nitroso compounds (not NDMA). This information is important in making comprehensive risk assessments of disinfection practices.

Prairie grasses are currently being used as biofiltration agents in removing pesticides from surface runoff and have been proposed as possible agents useful for phytoremediation of pesticide-contaminated soil. However, little research has been conducted on the fate of herbicides in prairie grass-soil environments. This study proposes to investigate the fate of metolachlor, atrazine, and pendimethalin in soil that has been planted with prairie grasses. Grasses grown in soil fortified with a radiolabeled herbicide will be placed in a sealed acrylic chamber. Volatile organic metabolites and CO2 will be analyzed throughout the experiment. In addition, plant and soil will be analyzed for total radioactivity, parent compounds and major metabolites after a remediation period. The proposed study will enhance our knowledge of the likelihood of the release of herbicides or possible bioactive metabolites back into the environment during and after biofiltration or phytoremediation. Additionally, insight will be obtained into the mechanisms of remediation, including the role of the plant.

Hydrogen sulfide (H2S) is a toxic gas generated in significant quantities from a variety of industrial processes, including wastewater treatment. Acute exposures to high levels of H2S (> 1000 ppm) have been fatal in many instances. Conflicting and sometimes inconclusive studies regarding the health effects associated with low level (<20 ppm) chronic exposure to H2S have led to increased interest in H2S both as an occupational and an ambient air pollutant. Very limited quantitative data exist on the longer-term low-level H2S exposures likely to be encountered everyday by workers in the wastewater treatment industry. By characterizing H2S exposures during specific tasks in four large and four smaller waste treatment facilities over an extended period, the study will collect information needed to conduct future risk assessments or epidemiological studies in order to characterize the health risks, if any, that may be involved in exposure to low concentrations of hydrogen sulfide. The study will also identify factors associated with potential high-level exposures.

This project will investigate reactions that could potentially reduce Disinfection By-Products (DBPs) in distribution systems. The researchers hypothesize that the dominant abiotic loss pathways involve reactions with pipe deposit material and with nascent cast iron, especially under reduced conditions. The objective of this research is to characterize the reactivity of selected DBPs with model and collected pipe deposit material, and with cast iron. A special emphasis will be on reactions with unidentified organic halide containing compounds, referred to as unidentified Total Organic Halogen uTOX. This material generally accounts for over 75% of the total halogen incorporated into organic matter.

Recent work on remediation of oxidized chemicals with permeable reactive barriers (PRBs) containing iron metal (Fe0) has shown that remediation performance is strongly affected by the layers of precipitates that form on the iron surface over time, and that the quantity and composition of these precipitates vary greatly depending on the composition of the groundwater. Despite the enormous success of Fe0 PRBs, the identity and significance of this surface precipitate is still unclear. This research proposes to develop a series of experimental protocols to characterize the composition of the surface precipitates forming in the Fe0 PRBs and evaluate how variations in solution chemistry are linked to changes in the precipitate coatings, which then enhance or inhibit PRB performance.

Currently there are no definitions of acceptable exposure or enforceable standards to hazardous bioaerosols that are associated with a high burden of morbidity and mortality. Emerging airborne diseases intensifies the importance of improving methodology for bioaerosol exposure assessment. Improvements will require characterizing the capabilities and limitations of existing methodology and the development of new techniques. Impinger samplers hold promise for current assessments, as they possess high collection efficiency and sample analysis flexibility. The study seeks to characterize the collection efficiencies of three commercially available impinger samplers using culture based and non-culture based methods of analysis. Information and data generated is intended to advance bioaerosol assessment in the present and improve methodology in the future.

Groundwater contamination by petroleum product releases is a common threat to public health. Contaminant plume dimensions and stability are important to characterize for risk management because they determine the area of influence and the potential duration of exposure. This project will analyze data from about 600 sites to identify central tendencies, variability, and regional trends of hydrocarbon plume characteristics. The data will be obtained from the Iowa Department of Natural Resources electronic database. Statistical analysis will be conducted to answer important questions, such as: What is a typical 'safe' distance down gradient of the source, beyond the reach of the plume? Technical Report Available.

This study will evaluate the quality of self-reports of pregnancy history information provided by female spouses enrolled in the Agricultural Health Study (AHS), a prospective cohort study of the occurrence of chronic disease among pesticide applicators and their spouses. Spouse self reports of pregnancy history information will be compared to those constructed from vital record data. Findings from this study will provide insights into the quality of pregnancy history information available in the AHS and preliminary data for future proposals.

Radon decay product (progeny) produces lung cancer in underground miners, yet epidemiologic studies examining residential radon gas exposure and lung cancer has yielded inconclusive results, raising the issue of whether residential radon progeny exposure poses a significant health risk. Radon decay products and not the radon gas itself deliver the radiological significant doses to the lungs, thus exposure risks need to measure actual radon progeny concentrations. This study proposes to update lung cancer risk estimates previously used in the Iowa Radon Lung Cancer Study using radon progeny dose measurement.

Bronchial asthma is a common clinical problem in the United States, affecting about 10 million people, or about 4% of the population. The occurrence of childhood asthma has increased in frequency, severity and rate of admisssion to hospitals in the U.S. This is in part due to greater recognition of asthma by families and health care professionals, but also appears to represent a true increase in disease, likely due to increased environmental pollution and allergens. This proposal outlines the first effort to identify prevalence, geographic distribution and seasonal patterns of childhood asthma using an asthma registry which is being initiated in Iowa. Rates of specific treatments will be calculated, based upon health care claims from three major insurers in Iowa. Secondary data representing environmental, climatological, socioeconomic and other patient factors will be analyzed to characterize their influence upon the prevalence and severity of childhood asthma in Iowa communities.

The goal of these studies is to determine the role of bacterial DNA in the development of Hypersensitivity Pneumonitis (HP), an environmental lung disease caused by contamination of hay by thermophilic bacteria. Previous studies have shown that Th1 responses with activation of Interleukin-12 are important in HP. Studies have shown that bacterial DNA is a powerful inducer of IL-12. The role of bacterial DNA in triggering the inflammatory response of HP is not known. To study this, a murine model of HP will be used, where mice will be intranasally installed with thermophilic bacteria. Groups of mice will be treated with thermophilic bacteria that have had the DNA destroyed and compared to groups treated with bacteria with intact DNA. The inflammatory response will be evaluated with histopathology, lung lavage cellarity and lung index. Cytokine responses will be evaluated in lung preparations. Less inflammatory and cytokine responses are expected in mice where DNA has been destroyed.

Exposures to grain dust aerosols in agricultural work environments have been linked to a variety of respiratory diseases, including occupational asthma, chronic bronchitis, and hypersensitivity pneumonitis. Agricultural workers are exposed daily to grain dust through combining, grain handling, mixing of feeds, or grain processing operations. Soybeans, which account for 1/4 of the crop value in Iowa, have been damaged increasingly by Sclerotinia sclerotiorum or "white mold", a fungal pathogen. There has been an increase in health complaints of Iowa soybean farmers following exposure to white mold as the proportion of the soybean crop infected with the mold has increased. Yang (1997) reported a doubling in the extent of white mold infestation since 1995. This project will investigate the respiratory health effects of exposure to S. Sclerotiorum and other soybean bioaerosols through inhalation toxicology studies using established animal models.

Advances in technology have created a multitude of airborne hazards that can affect the health and welfare of the population. Airborne toxic releases occur rapidly and the dispersed hazardous chemicals often present immediate acute health effects. The objective of this research is to develop a practical, workable approach for assessing the population at risk to accidents involving airborne toxic hazards. Methods based on the application of geographic information system (GIS) technology will be developed to achieve this goal. A particular emphasis will be placed on the identification of vulnerable population groups, including institutions (e.g., schools and hospitals) and their relationship to locations of potential hazardous material generation sites. In addition to integrating the key components of hazard analysis, the study will also extend and implement a new approach, known as geographic plume analysis, that accounts for directional biases in the distribution of hazards by using a chemical dispersion model to identify the area that is likely to be exposed to airborne toxic releases. Cedar Rapids, IA, will be used as a test-bed for developing these procedures.

The presence of aflatoxin B1 in agricultural soil poses a potential health risk to farmers from exposure to aerosolized soil dust during plowing and cultivation activities. In addition, aflatoxin B1 may constitute a health risk through contamination of surface water or groundwater. The primary purpose of this project is to investigate the presence and concentrations of aflatoxin B1 in Iowa. Supercritical fluid extraction (SFE), flow injection renewable surface immunoassay (FIRSI) with fluorescence detection, and HPLC/ES/MS methods will be developed and used for the determination of aflatoxin B1 and its transformation products in soil. This study will provide needed data to support external funding of a more detailed regional investigation of the fate and potential health risk of aflatoxin B1, as well as potential control and detoxification mechanisms.

Phytoremediation, the use of plants to remove environmental pollutants, holds great promise to reduce health risks associated with groundwater and soil contamination. Poplar trees can enhance site remediation by vegetative uptake of the contaminant or by enhancing its microbial degradation in the rhizosphere. This latter mechanism is not very effective for removing nitroaromatic contaminants. This project will evaluate the potential for a nitroaromatic-degrading, genetically-engineered microorganism (E. Coli DH5 [pDTG800]) to enhance bioremediation of 2,4,6-trinitrotoluene (TNT) in the poplar rhizosphere. The fate of both 14C-labeled TNT and E. Coli DH5 [pDTG800] will be studied in soil and plant bioreactors. The hypotheses are that 1) bioaugmentation of the poplar rhizosphere with this clone will enhance the mineralization of TNT; and 2) the added clone will maintain its nitroaromatic degradation activity and survive for a longer period of time in soil rhizosphere compared to background (control) soil. This research may lead to a better understanding and a more widespread acceptance of bioremediation in the rhizosphere as an additional tool for reducing health risks associated with environmental pollution.

Exposure to lead is now being recognized as a primary health hazard facing construction workers. Of particular concern are those activities that involve the demolition, repair and reconditioning of lead-based painted surfaces, such as bridge repair work, which generate significant airborne lead concentrations. Recently, several workers on a local bridge renovation project were diagnosed as having medical problems associated with overexposure to airborne lead. This overexposure was determined to result from lead dust generated during the operations necessary for bridge renovation: cutting, blasting, scraping, and hammering of painted metal surfaces. More information is needed concerning the fate of lead dust generated during bridge renovation and repair activities. This study will establish baseline data on the lead concentrations found at bridge repair sites, and use this data in exposure assessment and characterization by personal exposure monitoring and sampling during each of the activities involved in bridge repair operations.

In the United States, hardness (mostly magnesium and calcium) is removed from drinking water to prevent scaling of pipes and consumption of soap. Several studies indicate magnesium and calcium may be protective against heart disease. Removing hardness by ion exchange results in an increase in sodium concentration. Sodium is a well established risk factor for hypertension and resulting ischemic heart disease. An ecologic trends study of community mortality rates of heart disease in Iowa will be conducted to test three hypotheses: 1) mortality rates of heart disease are elevated in communities using ion exchange softening treatment; 2) communities using lime softening treatment have lower mortality rates of heart disease compared to communities using ion exchange; and 3) drinking water hardness may be protective against heart disease. Linkage of existing health outcome and municipal water quality databases maintained by the State Health Registry of Iowa and CHEEC will be a main component of this study. Significant differences in mortality rates of heart disease by type of softening treatments would indicate that more in-depth studies are warranted. Technical Report Available.

Atmospheric transport and deposition of pesticides are issues of significant concern. The presence of pesticides in rain implicates their presence in air, yet few, if any studies have analyzed ambient air for multiple residues of pesticides currently used. Atmospheric transport may be another important route of exposure to the general public and to sensitive, non-target ecosystems. This study will concurrently determine pesticides in air and rainfall at three sites - one farm, one urban, and one - to initially characterize agricultural and urban effects, and local and regional transport effects. Analytes include the pesticides commonly used in Iowa. A staggered sampling interval will characterize seasonal and temporal changes related to application periods. This project will develop some of the first data on year round ambient air pesticide concentrations. The findings will be the basis for expanded studies of exposure assessment, fate and transport, and non-target ecosystem effects.

The increasing contamination of groundwater by nitrate, primarily from the widespread use of commercial fertilizers, is an evolving public health concern in agricultural states. Nitrate can undergo endogenous reduction to nitrite, and nitrosation of nitrites can form N-nitroso compounds, which are potent carcinogens. There are few epidemiologic data, and no prospective cohort data, on whether nitrate exposure from drinking water increases the risk of cancer, in particular cancers of the digestive tract, the urinary tract, and non-Hodgkinlymphoma. This study proposes linking the Iowa WomenHealth Study, a prospective cohort study of cancer in women aged 55 to 69 years in 1986, to historical water quality databases available from CHEEC. Average nitrate exposure from drinking water over a 10 to 20 year window will be related to cancer risk, after adjustment for age, dietary nitrate intake, factors which impact endogenous nitrosation (vitamin C and E intake and smoking), and other site-specific confounders.

Fecal contamination of water supplies is a major cause of infectious disease with consequences ranging from minor illness to patient death. Current culture-based detection methods are decades old and take days to complete. Once identified, the presence of specific pathogens can take additional time. Clearly, the development of modern methods of detection are imperative. Automated polymerase chain reaction (PCR)-based methods would have major advantages over current procedures. The automation (1) minimizes risks of amplicon contamination and (2) allows for reliable, high throughput analysis. The PCR methodology (1) allows rapid turnaround time of hours instead of days, (2) permits adjustable sensitivity and specificity, (3) enables rapid subsequent analysis of positives samples to identify specific pathogens, and (4) identifies hard to culture pathogens. Such a system would help to minimize exposure to contaminated water sources and, when exposure has occurred, to rapidly guide appropriate antimicrobial chemotherapy, thus reducing morbidity and mortality.

Nitrate is the most common chemical contaminant in groundwater and drinking water in Iowa. This study will provide a cost-effective method for surveillance of nitrate contamination of private drinking-water supplies that can be used for exposure assessment, epidemiological studies, and monitoring of nitrate contamination over time. The University Hygienic Laboratory database of private well-water analyses (approximately 10,000 nitrate analyses/year) will be related to the Iowa Groundwater Vulnerability Regions (GVR) using the IDNR Geographic Information System. Zip-code areas will be spatially related to the GVR units and then the UHL water-quality data will be summarized by zip-codes, by GVR unit, by well depth, and by year. This will provide a sensitive analytical tool to assess spatial and temporal differences in water quality. It is proposed that this approach be used to develop an annual report of water-quality trends in Iowa, summarizing exposure and resource implications.

Strategies used to control lead and copper corrosion often produce insoluble surface coatings on distribution system pipes. Changes in overall water chemistry resulting from treatment alterations could have a major impact on the nature of distribution system deposits. Increased incorporation of radium could occur resulting in an increase in radon in the distribution system. This study explored the incorporation of radium into and radon release from deposit material formed when several corrosion control strategies used in water distribution systems are implemented. Phosphate containing coatings and deposits are a concern because phosphate bearing minerals can accumulate large amounts of radium. Of particular interest is determining the radium content of deposits under experimentally difficult conditions where small amounts of deposits are formed and little radium is actually removed from the water, but where the amount of radium per unit mass of deposits could be very high. Experimental results conclude: 1) Radium activity of pure calcium carbonate was much lower than the solid produced when either iron or zinc phosphate was added. The removal mechanism appears to be surface adsorption; 2) Addition of zinc phosphate greatly reduced the quantity of solids produced in the presence of calcium; 3) Radium removed from water when iron was added with zinc phosphate was significantly greater than that obtained with iron only; 4) Presence of calcium reduced radium removal from solution in the presence of iron and greatly increased the mass of deposit formed when phosphate was no present; 5) Percentage of radium removed from solution using orthophosphate in the presence of iron was approximately the same as that obtained using zinc phosphate at comparable dosages as phosphate; 6) Contrary to what might be expected from a cation sorption mechanism, the radium activity per unit mass of solid actually decreased as the pH increased; and 7) Results indicate zinc phosphate in the presence of 160 mg Ca/L and phosphate significantly increased radium accumulation.

Numerous climatic conditions and individual management aspects potentially effect bioaerosol concentrations in agricultural confinement buildings. The unprecedented flooding and heavy summer rainfall of 63.0 cm during 1993 in the state of Iowa provided the opportunity to compare bioaerosol concentrations in dairy barns that used hay and feed grown under wet conditions with bioaerosol concentrations in dairy barns that used hay and feed grown with a normal rainfall of 25.5 cm. Geometric mean time-weighted average viable bioaerosol concentrations in all 40 stanchion dairy barns sampled with an all-glass impinger (AGI) were 2 x 104 cfu/m3 for yeast, 0.9 x 104 cfu/m3 for molds, 80 x 104 cfu/m3 for mesophilic bacteria, and 0.3 x 104 cfu/m3 for thermophilic bacteria. Microorganism concentrations ranged 2-3 orders of magnitude between different barns. Correlation between the variance in microorganism concentrations and climate at time of sampling, ventilation systems, individual management practices, feed type, bed materials, and barn characteristics was assessed. The proportion of variance in microorganism concentrations associated with these variables, as determined by the squared multiple correlation coefficient ranged from 31% to 45%. Important individual variables that correlated with high bioaerosol concentrations were sampling during the distribution of bedding, the use of low storage moisture feeds, and mixing fan type ventilation. Variables that were correlated with low bioaerosol concentrations were tunnel ventilation and the use of high storage moisture feeds. For the 4 classes of microorganisms studied, no correlation (all p0.20) was found with rainfall. Thus, these data refute the common assumption that in-barn use of hay and feed grown under wet conditions leads to significantly higher bioaerosol concentrations. Additional funding to continue research has been provided by the Center for Disease Control, National Institute of Occupational Safety and Health.

This project will provide information on environmental health issues concerning air quality in the vicinity of swine confinement operations in Iowa. The investigation utilizes a questionnaire distributed to residents who live near hog production facilities. The questionnaire measures physical or psychological symptoms associated with nearby hog confinements. Site selection of hog facilities included non-confined hog lots, lagoon/large hog confinements (1000 plus hogs), and medium sized hog confinements with open lagoons. Air samples were taken upwind, downwind, and next to each facility to determine the levels of dust, hydrogen sulfide, and ammonia concentrations present.

Seasonal and short-term temporal variations of radon suggest that one-time sampling of water supplies may not produce a representative sample of well water. Obtaining concentration levels of water supplies at or near the proposed U.S. EPA Maximum Contaminant Level is complicated by these variations. The aims of this research are to determine temporal variations in ²²²Radon in community water supplies looking specifically at water use, temperature, precipitation, and barometric pressure; determine the relationship between raw and finished water ²²²Radon concentrations over time in water supplies where ²²²Radon in finished water exceeds that in raw water; and propose a sampling scheme which will provide a representative ²²²Radon water concentration.

The purpose of this study was to assess exposure of four trihalomethanes (THMs-chloroform, dichlorobromomethane, dibromochloromethane, and bromoform) in tap water and indoor air. Measurements of tap water and indoor air during and after showering were taken in residential homes. Houses using private well water (non-chlorinated), public groundwater supply (chlorinated), and public surface water sources (chlorinated) were all evaluated in the study. Water and air samples were collected for each event. THM concentration was taken in the tap water during showering, air samples were collected in the bathroom prior to shower, during showering, and a third air sample was collected in the living room area 30 minutes after showering. Results showed highest THMs in public surface supply, followed by the public groundwater supply. No THMs were detected in the private well water. The public groundwater supply was the only water sampled with all four THMs present. In air samples for the public surface water supply, dibromochloromethane and chloroform were detected. During shower air samples showed an increase in THMs, thus indicating volatilization from the water. In the public groundwater supply, chloroform was the most frequently observed THM. The study reports that while THM concentrations within public groundwater supplies tended be low (5 ppb), THMs were consistently present in the air samples in the living room area. For private wells with no chlorination, THMs were not present in the water, nor were they consistently present in air samples. When there was a positive detection in the air, it was attributed to a running dishwasher in the kitchen that used a detergent containing chlorine bleach. This study shows that showerers are exposed to low levels of THMs in the air during a shower and it may be worthwhile to further quantitate effects of water temperature or bathroom ventilation to be able to recommend ways of minimizing exposure. Technical Report Available.

Monochloramine (NH2Cl) produced from the reaction of free chlorine and ammonia in a process called chloramination, is generally considered to be a leading candidate as an alternative disinfectant to replace free chlorine which is known to produce a variety of potentially mutagenic and carcinogenic organic by-products. However, while chloramination produces fewer organic byproducts, recent work has shown that at least one unidentified inorganic decomposition product is formed. The existence of an unidentified product should be a cause of concern because of potential health effects. This research focus on the characterization, identification, and quantification of the unknown(s) produced in chloraminated drinking water under a variety of reaction conditions. This will be done by 1) conducting detailed mass balances on chlorine and nitrogen, 2) developing methodology to separate and concentrate the unknown(s), and 3) applying mass spectrometry and NMR techniques to characterize structure. Expanded research is being funded by a grant from AWWARF.

Understanding the relationship between environmental exposure and blood lead concentration in children has been complicated by the lack of standardized sampling methodology. The specific goal of this project was to evaluate and compare three methods for sampling lead-containing dust on interior surfaces. Lead-containing dust at three different concentrations was generated in a cubic-meter chamber and uniformly deposited onto a variety of surfaces typically found in the home environment (painted wood, unpainted wood, varnished wood, linoleum, and carpet). Surface dust samples were collected using Whatman filter paper #42 wetted with distilled water (OSHA method), commercial wipes with a non-alcohol wetting agent (the wipe method recommended by HUD for dust clearance after lead abatement), and a vacuum filter method using cellulose acetate filters in 35 mm cassettes at a flow rate of 2 Lpm (vacuum method). Results showed on most surfaces (painted wood, unpainted wood, varnished wood and linoleum) the recovery of the HUD method was significantly higher than the vacuum method and the OSHA method. On carpet, the recovery using the vacuum method was significantly higher. For all wipe sampling methods the recovery depends on the surface characteristics.

Collection of family history data is important when evaluating environmental and genetic risk factors associated with epidemiologic studies. The aims of this study were to determine the percent concordance between maternal interview responses for family history information and blood relative questionnaire responses, and assess the independent effects of maternal age, education, income, marital status, gravidity, and study group status (case or control) on the validity of family history information provided by maternal interview. The results of the research suggest blood relative birth defect and cancer diagnoses provided by study mothers should be viewed with caution. Sensitivity estimates of maternal responses for blood relative birth defect diagnoses were low for both case and control groups. In contrast, sensitivity estimates of maternal responses for blood relative cancer diagnoses were higher for case mothers than control mothers. No independent factors of maternal age, education, income, marital status, gravidity, and study group status on the sensitivity of maternal telephone interview responses were found to be associated with sensitivity for blood relative birth defect diagnoses. For blood relative cancer diagnoses, analyses suggest that study group status was a significant factor in the determination of sensitivity with control mother reports being less accurate than case mother reports. Results of this study will be used to establish subject recruitment protocol and to design the family history questionnaire for an upcoming multi-state genetic epidemiologic case-control investigation of facial clefts.

The purpose of this study was to determine whether plant activated mutagens could be detected and quantitated from drinking water samples obtained from the Rathbun Rural Water Association. Plant activation refers to the process in which a non-mutagenic agent is transformed by biological action of a plant into a mutagen. Water samples collected were fractionated and concentrated with a 0.2 m tangential flow ultrafiltration membrane, then passed through a NA+ charged cation column. Aliquots were taken after the 0.2 m filter and cation exchange to measure DOC adsorption. The sample was then passed through in a series, a polysulfone 30 kDa ultrafiltration membrane, a poly sulfone 1 kDa ultrafiltration membrane, and a polyamide reverse osmosis membrane. A mass balance analysis based on total organic carbon was conducted on the drinking water and each size fraction. Weak positive responses were observed in one 1 kDa retentate and in two reverse osmosis retentates. In all three cases, there was an initial yet weak statistically significant increase in the mutagenicity of the tested samples. The research concluded that concentrated fractions of Lake Rathbun were rather benign. Even after many fold concentration and analysis with highly sensitive Salmonella mutation tester strains, only a weak positive response was observed with two fractions.

The purpose of this study was to determine if evidence of radon formation exists in water distribution systems exposed to radium bearing water. The significance of radium bearing deposits in an actual distribution system depends on a number of factors, including radium content of the pipe deposit, the amount and distribution of pipe deposits, the type of deposits, and the time in which a given water volume is in contact with deposits. The study concludes that radon produced in radium-bearing deposits in the distribution system may cause radon to significantly increase in concentration. Even though the source of the deposit within a distribution system may be small in comparison to a geological source and impact only a very small fraction of the population, the importance must be gauged by the proposed maximum contamination level (MCL) of 300 pCi/L. Radon production within the distribution system may cause radon content to exceed the MCL for some users, even if compliance of the point of entry is achieved. The linkage between radium deposition and radon release may need to be considered in the final EPA radionuclide regulations.

The goal of this project was to assess the joint influence of home construction and environmental (soil) characteristics in predicting radon concentration in homes. The first part of this work found the relationship between radon concentration and home construction factors was dependent on location of the radon test in homes. In basements, wall construction and degree of energy efficiency predominated in predicting radon concentration. On upper floors, age of home predominated in predicting radon concentration, with a general decrease in radon concentration with age of home. The second part of the study found texture of the soil on which the home is located was the most important predictor of radon concentration for homes tested in the basements. Precipitation totals in the year preceding the screening test were negatively correlated with radon concentration in homes, but the relationship was only apparent when basement wall type and soil texture was accounted for.

This study represents the first statewide random sampling of private water-borne radon-222 in the nation, and also collected information on radium-226 and radium-228. The health risks of water-borne radon-222 are considered high, and the U.S. EPA has proposed a maximum contaminant level (MCL) of 300 pCi/ L for public water supplies. Study findings include: 1) Participant collected samples at the point-of-use are comparable to samples professionally collected; 2) Fifty-two percent of the wells sampled had waterborne radon-222 concentrations that exceeded the proposed MCL; 3) Radon-222 concentrations in private well-water are slightly higher than groundwater supplies. (This is attributed to a higher percentage of private wells drilled into Pleistocene till which often produce higher waterborne radon-222 concentrations, while public supplies are preferentially drilled into alluvial deposit, which generally contain less radon-222 precursor material); 4) The western part of the state has the highest mean radon-222 well-water concentrations as a result of the large number of wells drilled into the Pleistocene; 5) Radon-222 samples did not vary temporally during the one year collection period; 6) The contribution of well-water derived indoor air radon-222 is minimal compared to subsurface soil and rock radon-222 sources in Iowa; and 7) Well depth, well-water radium-226, well-water radium-228, and indoor screening of radon-222 are all extremely poor predictors of well-water radon-222 concentrations. Additionally, because of the huge variations of waterborne radon-222 concentrations noted for the specific aquifer type, their usefulness as a predictor of waterborne radon-222 concentration is limited.

Aflatoxins are recognized as potent chemical carcinogens, have been associated with liver cancer in animal studies, and may be associated with lung cancer incidence in humans exposed to aflatoxins in contaminated grain dust. This project developed and validated a one-step extraction and analysis technique for the separation and quantitative determination of low levels of aflatoxins in airborne grain dust samples. This technique is faster, more sensitive, more selective, and more reliable than present methods. The method is based on the use of supercritical fluid extraction (SFE) on line with gas chromatography or supercritical fluid chromatography followed by mass spectrometric detection (SFE/GC/MS or SFE/SFC/MS). In addition, preliminary data on the levels of aflatoxins in grain dust generated during harvest and on-farm grain handling operations were collected. Results from this study were used to acquire a grant from the National Institute for Occupational Safety and Health to expand research.

The effects of pesticide contamination of drinking water on human reproductive health are largely unknown. In a statewide survey of 856 Iowa municipal drinking water supplies in 1986-1987, a rural water system supplied by the Rathbun Reservoir was found to have elevated levels of the herbicide atrazine, 2.2 mcg/l vs. 0.6 mcg/l in other Iowa surface water supplies. Rates of low birth weights, prematurity, and intrauterine growth retardation (IUGR) in live singleton births during 1984-1990 in women living in 13 communities served by the Rathbun water system were compared to other Iowa communities. The Rathbun communities had a significantly greater risk of IUGR than southern Iowa communities with other surface sources of drinking water. Multiple linear regression analyses revealed that levels of the herbicides atrazine, metolachlor, and cyanazine were each significant predictors of community IUGR rates in southern Iowa after controlling for several potentially confounding factors including maternal smoking and socioeconomic variables. The association with IUGR was strongest for atrazine, but all three herbicides were correlated. The independent contributions of each to IUGR risk could not be determined.

Urban-rural differences in cancer incidence and mortality rates were evaluated in a descriptive epidemiologic study among Iowa residents (1973-1988). Results were based on two separate definitions of urban and rural-one county boundary based and the other based on application of an address algorithm. Both definitions yielded similar findings. Two different definitions of mortality were used. The first definition included as an eligible death only those cases where cancer was listed as the underlying cause of death , whereas the second definition included all conditions of cancer where cancer was listed on the death certificate as the underlying cause or as a contributing condition. Study findings were 1) Smoking-related cancers were found to be significantly higher in urban areas relative to rural areas for males and females, and mortality from smoking-related cancers was greater in urban areas; 2) Lip cancer in males was the only cancer site with a significantly elevated rate in rural areas relative to urban areas, all other cancers were higher for urban areas, for both males and females; 3) Better sensitivity was established when using the 'all causes of death' definition, and use of the application algorithm proved more sensitive as well; and 4) Cancer mortality rates were generally higher in those urban and rural areas that had higher cancer incidence rates. An additional research project was funded by the National Cancer Institute to investigate these findings further. Technical Report Available.

The aim of this study was to develop a monoclonal antibody specific for the common herbicide glyphosate (trade name: Roundup), and develop an immunoassay system for the rapid detection of glyphosate in water samples. Immunoassays would dramatically reduce the costs of water sampling for glyphosate as compared to current analytical methods. The glyphosate molecule is quite small, and has only three chemically distinct sites. Because of these few small sites available for attachment, problems have been encountered by other researchers in developing a immunoassay system for glyphosate. The CHEEC researchers, too, encountered similar difficulties and were unsuccessful in their attempts at developing an immunoassy for glyphosate. Researchers on this project theorized devising a scheme for creating an attachment site internal to the glyphosate molecule, thus presenting the molecule in its native form. Researchers determined this was possible, but this synthesis and process was beyond the scope and resources of this seed grant.

Progressive global stratospheric ozone depletion and the resulting elevation in ultraviolet radiation presents the prospect of a significant human health hazard. In the eye, the cornea, lens, and retina have well-established UV radiation pathologies. Increased UV exposures may also intensify the UV-phototoxicity in some therapeutic agents widely used by the general public. This study examined a number of anti-inflammatory analgesics know to be UV-phototoxic in the skin, but with as yet unreported effects in the eye. Study investigators hypothesize that these widely used drugs compound the risk of retinal damage in people who have outdoor occupations.

This study researched the feasibility of performing DNA ploidy analysis on formalin-fixed tissue from patients who participated in a statewide, population-based, case-control study, and who had tumorous tissue removed at the University of Iowa Hospitals and Clinics. Eligible cancer sites included the kidney, colon, and rectum. A data collection form was developed and ploidy analysis was run. These analysis were correlated with known pathologic predictors of outcome, as well as with known risk factors for colorectal carcinoma. Results showed no strong associations between ploidy status and survival predictors nor with any dietary and other potential risk factors.

This project examined the feasibility of point-of-use (POU)/ point-of-entry (POE) ozone treatment systems for in-home use, and their effectiveness at removing the commonly applied pesticides alachlor, atrazine, cyanazine, metolachlor, metribuzin, and propachlor. Tests were conducted in open and closed systems, and efforts were made to simulate probable demand on the system for in-home use. The effectiveness of the ozone system demonstrates oxidation of the pesticides is closely related to the compound oxidized, the pesticide concentration, the ozone concentration, and contact times. Ranking these compounds to their susceptibility to ozone oxidation, metribuzin is the most easily oxidized, followed by alachlor, metolachlor, atrazine, propachlor, and cyanazine. From the tests performed, given a large enough concentration times time (CT) value, oxidation of the pesticides tested to concentrations below health advisory standards can be achieved through ozone POU/POE systems. A follow up study, titled Destruction of nitrogenous pesticides by combined ozone/H2O2 and enzymatic polymerization process was funded by EPA Hazardous Substance Research Center, Region 7.