Ambient air pollution sources are one of the potential environmental exposure sources that have been suggested to influence childhood asthma. Though asthma research has been done in many cities, little is known about asthma risk factors in rural populations. This study will both explore and experiment on the distributions of asthma cases and controls from the Keokuk County Rural Health Study in the context of neighboring point source air polluters such as hog-lots and grain mills. Space, time, space-time interaction, space-time clustering, and spatial regression analyses will be performed using recently developed spatial statistical tools. The hypothesis will be tested that asthma cases are found to be significantly closer to point source air polluters within the Keokuk Country area than the control group.