PT02 Soil Toxicology and Risk Assessment
Exhibit Hall
8:00 AM - Tuesday, 11 November 2003
(PT021) Evaluation of Exposure to Heavy Metals from Red Dog Mine in Northwest Alaska.
Arnold, S1, Lynn, T1, Middaugh, J1, 1 Alaska Division of Public Health, Anchorage, AK, USA
ABSTRACT- In 2001, the Alaska Division of Public Health (ADPH) conducted an investigation to determine if lead and zinc mining operations at the Red Dog Mine were exposing nearby village residents to lead and other metal concentrations that could adversely affect their health. To determine the potential exposure to metals, ADPH reviewed data of blood-lead levels (BLLs) of nearby residents and mine workers, rat-feeding studies designed to determine the bioavailability of the lead contained in the ore concentrate, and water, soil, sediment, caribou, salmonberry, and Dolly Varden metal concentrations. The geometric mean BLLs from past testing of children (0-12 years) from the villages of Kivalina (n=146), Noatak (n=128), and Point Hope (n=6) were < 5 
g/dL. Recently hired mine employees never exposed to the ore concentrate from two nearby villages (n=35) had geometric mean BLLs of ≤ 3.7 g/dL. Geometric mean BLLs for mine employees (n = 414) working in departments not in contact with the ore were ≤ 4.1 g/dL. Rat-feeding studies indicated that the bioavailability of the lead sulfide contained in the ore is low. The concentrations of metals detected in water, soil, caribou, Dolly Varden, and berries from the Red Dog mine area (excluding the port, haul road, and mine) were below risk-based screening concentrations and represented natural background concentrations. The general public is excluded from the mine and the port areas where concentrations of lead (36,000 mg/kg) and zinc (180,000 mg/kg) were elevated. Exposure pathways for nearby residents were not identified, and additional blood-lead testing of residents of communities nearest to the mine was not indicated.
Key words: Alaska, lead mine, human health, subsistence