This report presents an assessment of human health risks from exposure to surface soil metals in the Old Tungsten Mill, Tucson, AZ. City of Tucson officials had planned to build a park, on a parcel of land they owned west of Silverbell Road and north of Speedway Boulevard in Tucson, Pima County, Arizona. They had raised $200,000 in bond money to study what was the Old Tungsten Mill site when they found high levels of contaminants in the soil. The Arizona Department of Health Services, Risk Assessment & Health Consultation Program offered assistance to the city. On October 13th, 2006 City Officials asked ADHS to perform a health consultation to evaluate whether exposure to contaminants in soil pose a public health hazard, either currently or during possible future reuse of the land.

The Arizona Department of Health Services prepared this report to evaluate whether a public health hazard exists as a result of potential environmental exposures from the contamination at the Phoenix Goodyear Airport North site. Another objective of this report was to investigate and address the health concerns of the residents in the Goodyear area, including former Unidynamics workers. This report uses available environmental data from the site and information collected from members of the community regarding their health concerns. There were many concerns, including health concerns, of residents and former Unidynamics workers that were related to living near the PGA North site or previous employment at the former Unidynamics facility. These community concerns are identified and addressed in the public
health assessment.

The Arizona Department of Health Services was asked by the Arizona Department of Environmental Quality to evaluate the potential health effects from inhalation of toxic vapors as a result of an unplanned, concentrated nitric acid release. According to Hudson Farms, at approximately 1 pm on July 1st, concentrated nitric acid began escaping from a small leak in a 33,000 gallon storage tank. By 4:30 pm, the first responding fire department units observed an orange colored plume that was moving with the wind direction. The large plume continued to dissipate throughout the area until about 8:30 pm that night. Small amounts of nitric acid that was generally restricted to the Hudson property continued to leak until approximately 8 am the morning of July 2nd when pumping of acid waste waters into emergency storage tanks was completed. It is estimated by ADEQ that a total of 4,0 00-4,500 gallons of concentrated nitric acid was released from the storage tank. Approximately 600 people from the town of Laveen and the Gila River Indian Community were immediately evacuated. Residents were allowed re -entry to their homes the following day, July 2nd at approximately 10 am.