Organochlorines, Lead, and Mercury in Akwesasne Mohawk Youth. (Children's Health)
Schell, Lawrence M., Hubicki, Lech A., DeCaprio, Anthony P., Gallo, Mia V., Ravenscroft, Julia, Tarbell, Alice, Jacobs, Agnes, David, Dawn, Worswick, Priscilla, Environmental Health Perspectives
Most humans have detectable body burdens of polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and p,p'-dichlorophenyldichloroethylene (p,p'-DDE), a metabolite of p,p'-dichlorodiphenyltrichloroethane (DDT). Native American communities may be at increased risk of exposure through subsistence-based diets and greater physical contact with contaminated soil and water. In this article we describe the levels of toxicants (PCBs, p,p'-DDE, HCB, mirex, lead, and mercury) among youth 10-17 years old (n = 271) of the Akwesasne Mohawk Nation. Ultratrace, congener-specific PCB analysis of human serum quantitated 83 PCB congeners (plus 18 as pairs/triplets), in addition to p,p'-DDE, HCB, and mirex, and included all major Aroclor-derived congeners typically present in human samples. Twenty congeners (in 16 chromatographic peaks) were detected in 50% or more of the individuals sampled [geometric mean (GM) of the sum of these congeners = 0.66 ppb]. Thirteen congeners (in 10 peaks) were detected in 75% or more of the samples (GM = 0.51 ppb). Of the 20 congeners detected in 50% or more of the samples, 17 had five or more chlorine substitutions. International Union for Pure and Applied Chemistry congeners 118, 101(+90), and 153 were detected in nearly all participants (GM = 0.06 ppb, 0.05 ppb, 0.09 ppb, respectively), p,p'-DDE and HCB were detected in 100% and 98% of the samples (GM: p,p'-DDE = 0.37 ppb; HCB = 0.03 ppb). Mirex was detected in approximately 46% of the samples (GM = 0.02 ppb). No cases of elevated lead level were observed. One participant had a mercury level marginally higher than the U.S. Environmental Protection Agency's current level of concern (0.50 [micro]g/dL). Although differences in analytic methods and participant ages limit comparability, toxicant levels from the Mohawk youth are lower than those associated with severe food contamination (Yusho and Yu-cheng) but similar to other chronically exposed groups. Key words: adolescents, Iroquois, Native American, persistent organic pollutants, polychlorinated biphenyls, toxicants.
Persistent organic pollutants (POPs) are a group of compounds that includes polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), hexachlorobenzene (HCB), and mirex. These compounds are lipophilic and bioaccumulate (Matthews and Dedrick 1984). They and/or their metabolites have entered the environment and the food chain and can be detected at some level in many, if not all, human populations (Stehr-Green 1989). A major route of POP intake in humans is consumption of contaminated food (Liem et al. 2000; Patandin et al. 1999). In addition, POPs cross the placenta and are transferred through lactation, resulting in exposure to the fetus and to infants. Some PCBs (i.e., the coplanar congeners) resemble 2,3,7,8-tetrachlorodibenzo-p-dioxin (Safe 1994) and produce biologic effects associated with binding to the aryl hydrocarbon (Ah) receptor. In contrast, documented or suspected biologic effects of non-coplanar PCB congeners include disruption of the development and functioning of some endocrine pathways and altered growth, development, and cognitive function in nonhumans and humans (American Council on Science and Health 1997; Brouwer et al. 1999; Carpenter et al. 1998; Schell 1999; Seegal 1996; Swanson et al. 1995).
Previous studies of environmental contamination such as the Exxon Valdez disaster (Palinkas et al. 1992) as well as other work (Akwesasne Task Force on the Environment 1997; Curtis 1992; Grinde and Johansen 1995; Harris and Harper 1997; Hild 1998) have indicated that Native peoples may be differentially exposed to toxicants. They are at particular risk of exposure to environmental contamination because of traditional dietary patterns involving consumption of locally caught fish and riverine species (Sloan and Jock 1990). Also, increased exposure may result from activities involving greater contact with the outdoor environment, such as swimming, wading, hunting, trapping, small-scale farming, and gathering traditional plants for medicines, foods, and other uses (Arquette et al. …