History of Inuit Community Exposure to Lead, Cadmium, and Mercury in Sewage Lake Sediments Mark H. Hermanson1 and James R. Brozowski2 1Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA; 2Department of Soil, Water, and Climate, University of Minnesota, St. Paul, Minnesota, USA Abstract Exposure to lead, cadmium, and mercury is known to be high in many arctic Inuit communities. These metals are emitted from industrial and urban sources, are distributed by long-range atmospheric transport to remote regions, and are found in Inuit country foods. Current community exposure to these metals can be measured in food, but feces and urine are also excellent indicators of total exposure from ingestion and inhalation because a high percentage of each metal is excreted. Bulk domestic sewage or its residue in a waste treatment system is a good substitute measure. Domestic waste treatment systems that accumulate metals in sediment provide an accurate historical record of changes in ingestion or inhalation. We collected sediment cores from an arctic lake used for facultative domestic sewage treatment to identify the history of community exposure to Pb, Cd, and Hg. Cores were dated and fluxes were measured for each metal. A nearby lake was sampled to measure combined background and atmospheric inputs, which were subtracted from sewage lake data. Pb, Cd, and Hg inputs from sewage grew rapidly after the onset of waste disposal in the late 1960s and exceeded the rate of population growth in the contributing community from 1970 to 1990. The daily per-person Pb input in 1990 (720,000 ng/person per day) exceeded the tolerable daily intake level. The Cd input (48,000 ng/person per day) and Hg input (19,000 ng/person per day) were below the respective TDI levels at the time. Key words: cadmium, Canada, exposure, history, Inuit, lakes, lead, mercury, sediments, sewage. Environ Health Perspect 113:1308-1312 (2005) . doi:10.1289/ehp.7985 available via http://dx.doi.org/ [Online 31 May 2005] Address correspondence to M.H. Hermanson, Department of Chemistry, University of Pennsylvania, 231 S. 34th St., Philadelphia, PA 19104-6323, USA. Telephone: (215) 573-8727. Fax: (215) 573-2112. E-mail: mhherm@sas.upenn.edu Assistance in Sanikiluaq came from B. Fleming, J. Meeko Jr., M. Weesk, L. Kittosuk, and P. Kattuk. P. Kiry assisted with laboratory analysis. This work was conducted under license 12419R from the Science Institute of the Northwest Territories. It was partially funded by the Hamlet of Sanikiluaq. The authors declare they have no competing financial interests. Received 1 February 2005 ; accepted 31 May 2005. The full version of this article is available for free in HTML or PDF formats. |