In March 2004, a resident of Cornville contacted the Arizona Department of Environmental Quality to request information on arsenic in drinking water. The resident collected six well water samples from their own well and neighbors’ wells and submitted them to a private laboratory for arsenic analysis. The analyses detected arsenic ranging from 15 to 952 μg/L. ADEQ and the community members asked the Arizona Department of Health Services to provide health information about using the water. Initial conversations with the well owner and other community members revealed that many people had concerns about potential health effects from arsenic exposure.

A refuse dump near Naco, Sonora, Mexico, caught fire and burned from December 1 to December 5, 2001. The fire, which consumed large quantities of household refuse, also generated a large quantity of smoke. During this period, considerable smoke was intermittently present in Naco, Arizona. This report summarizes the events that occurred during the fire and analyzes the data collected by the Arizona Department of Health Services and the Arizona Department of Environmental Quality to determine the extent of the public health threat from the fire.