The District of Columbia area has one of the greatest health disparities of cancer in the nation and ranks seventh highest for the most unhealthy places to live due to poor air quality (EPA Report, 1999). Also, a 1999 report from the Centers for Disease Control stated that the District had the highest overall rate of cancer incidence in the nation. One of the major contributors to pollution in our environment is particulate matter. Quite often particulate matter is composed of toxic materials including heavy metals, pesticides, and spores. In some cases, these heavy metal particulates are considered carcinogenic. They are typically characterized as particles with diameters smaller than 1 um and are easily deposited into the alveolar regions of the human lungs which can impose threatening health risks. In this study, I will design and execute an environmental health exposure assessment for chromium, as well as lead, cadmium and arsenic, in four observed wards of Washington, D.C., and correlate this data to heavy metal exposure levels and toxicity. These datasets will then be related to epidemiological data and health outcomes for the observed areas of study.