Monica Ramirez-Andreotta, PhD
Risk Assessment: Lead exposure in children living near a legacy mine and copper smelter in Hayden-Winkelman, Arizona
Background: Lead exposure has been shown to be harmful to humans in various settings. Lead is particularly harmful to children, in whom it can cause neurological problems, low IQ, developmental delay, and other health issues. There are no safe levels of blood lead in children. At the ASARCO Alternative Superfund site in Hayden-Winkelman, AZ, lead exceedances in air and soil have been measured in the past 20 years. An important question is whether these lead levels can be expected to impact the health of children in the community. Over 140 children under age 11 live in Hayden and Winkelman; the majority within a quarter-mile of the smelter. This project focuses on assessing their risks. Methods: Using the U.S. Environmental Protection Agency’s Integrated Exposure Uptake Biokinetic (IEUBK) model, we estimated Hayden-Winkelman, AZ children’s (0-7 years) blood lead levels using site-specific lead concentrations measured in indoor and outdoor air, soil, indoor dust, and water. Values used by the Arizona Department of Environmental Quality’s airborne lead risk forecast were also evaluated in the IEUBK model to determine whether the forecast provides an accurate representation of risk ranges for children in the community when coupled with other measured lead exposures on the site. Results: A simulated population of children living in Hayden-Winkelman is at risk of blood lead levels (BLLs) considerably higher than the 5 ug/dL level of concern used by the Centers for Disease Control. The ADEQ’s (outdoor) airborne lead risk forecast levels do not provide protection to community children because high indoor dust lead levels are chiefly responsible for the high percentage of children with high BLLs in the simulation.