Ken Sexton1*, John L. Adgate, Ann L. Fredrickson, Andrew D. Ryan, Larry L. Needham, and David L. Ashley, University of Minnesota School of Public Health, MMC 807, Mayo building 420 Delaware Street, S.E., Minneapolis, MN 55455-0392
Concurrent exposure to a mixture of more than 50 environmental chemicals was assessed by measuring the chemicals or their metabolites in blood of 43 ethnically diverse children (3 – 6 years old) from a socioeconomically disadvantaged neighborhood in Minneapolis. Over a two-year period, additional samples were collected every 6 – 12 months from as many children as possible. Blood samples were analyzed for 11 volatile organic compounds (VOCs), 2 heavy metals – lead (Pb) and mercury (Hg), 11 organochlorine (OC) pesticides or related compounds, and 30 polychlorinated biphenyl (PCB) congeners. The evidence suggests that numerous VOCs originated from common sources as did many PCBs. Longitudinal measurements indicate that between-child variance was greater than within-child variance for 2 VOCs (benzene, toluene), for both heavy metals (Pb, Hg), for all detectable OC pesticides, and for 15 of the measured PCB congeners (74, 99, 101, 118, 138-158, 146, 153, 156, 170, 178, 180, 187, 189, 194, 195). Despite the relatively small sample size, highest measured blood levels of 1,4-dichlorobenzene, styrene, m-/p-xylene, lead, mercury, heptachlor epoxide, oxychlordane, p,p’-DDE, trans-nonachlor, and PCBs 74, 99, 105, 118, 138, 146, 153, 156, 170, and 180 were comparable to or higher than 95th percentile measurements of older children and adults from national surveys.
Results demonstrate that cumulative exposures to multiple environmental carcinogens and neurotoxins can be comparatively high for children from a poor inner-city neighborhood.