Local residents expressed their concerns regarding the tailings from the Iron King Mine and Humboldt Smelter at Dewey-Humboldt, AZ. The purpose of this health consultation is to evaluate the available water and soil sampling results to determine if the detected metal levels pose adverse health effects when residents come into contact with the water or soil. In 2008, EPA initiated the field investigation portion of the Remedial Investigation and Feasibility Study for the Site. The primary objectives of the RI/FS are to determine the nature and extent of contamination and to gather sufficient information so that EPA can select a long-term remedy that eliminates, reduces, or controls risks to human health. The investigation included the collection of airborne particulates, groundwater, surface water, surface soil, subsurface soil, and sediment data across the entire Site. Data from the RI/FS was not available at the time the health consultation was prepared and thus it was not incorporated into this health consultation.

The Santa Cruz County Health Department and the sheriff's office, along with the U.S. Border Patrol have expressed concerns regarding incidental contact with the water in Nogales Wash, Arizona. The public has expressed significant concern about direct public exposure to waters flowing in the wash. The Arizona Department of Health Services completed this health consultation to evaluate the levels of organic and inorganic chemicals at the request of the Santa Cruz County Health Department.