Assessing Metals Exposures in the Community Surrounding the Iron King Superfund Site
The Iron King Mine and Humboldt Smelter in Northern Arizona were operational from the 1880s-1960s, resulting in millions of square feet of left-over material and by-products, and recently the US EPA has designated this area a Superfund Site. Potential metals exposure to the surrounding communities has come into question, and in response to this concern, we conducted a multi-media exposure assessment. We collected biological samples from children ages 1-11 living within 5 miles of the Site, along with environmental samples at their home. Samples were analyzed for arsenic, beryllium, aluminum, nickel, lead, cadmium, and chromium via ICP-MS. A set of questionnaires were also administered to address the child(ren)’s potential exposure to metals. We found that arsenic levels in urine were above that of the general population according to the National Health and Nutrition Examination Survey (NHANES). Also, we found arsenic in tap water were above the Maximum Contaminant Level (MCL) for drinking water and levels in the soil and house dust were above the Arizona Department of Environmental Quality’s Soil Remediation Level (SRL). Arsenic in the children's toenails were significantly correlated with both soil and dust, and the arsenic in urine was significantly correlated with water and dust. Dust transport modeling is currently being conducted to better understand the potential for arsenic contamination to be transported from the Site to homes in nearby communities. The source(s) of metals found at the home and activity patterns contributing to exposure in the home and children’s biomarkers are also being explored. This study has the potential to inform the development of future interventions aimed at decreasing arsenic levels in the homes near the Iron King Mine and Humboldt Smelter Superfund Site.