single blood-hg samples can result in exposure misclassification temporal monitoring within the japanese community (united states)单一blood-hg样本可能导致暴露错误分类时间监视日本社区内(美国).pdf

Tsuchiya et al. Environmental Health 2012, 11:37 /content/11/1/37 RESEARCH Open Access Single blood-Hg samples can result in exposure misclassification: temporal monitoring within the Japanese community (United States) 1 2 3 4 1 1 Ami Tsuchiya , Rob Duff , Alan H Stern , Jim W White , Finn Krogstad , Thomas M Burbacher , Elaine M Faustman1,5 and Koenraad Mariën4* Abstract Background: The most prominent non-occupational source of exposure to methylmercury is the consumption of fish. In this study we examine a fish consuming population to determine the extent of temporal exposure and investigate the extent to which single time estimates of methylmercury exposure based on blood-Hg concentration can provide reliable estimates of longer-term average exposure. Methods: Blood-mercury levels were obtained from a portion of the Arsenic Mercury Intake Biometric Study (AMIBS) cohort. Specifically, 56 Japanese women residing in the Puget Sound area of Washington State, US were sampled on three occasions across a one-year period. Results: An average of 135 days separated samples, with mean blood-mercury levels for the visits being 5.1, 6.6 and 5.0 μg/l and geometric means being 2.7, 4.5 and 3.1 μg/l. The blood-mercury levels in this group exceed national averages with geometric means for two of the visits being between the 90th and 95th percentiles of nationally observed levels and the lowest geometric mean being between the 75th and 90th percentile. Group means were not significantly different across sampling periods suggesting that exposure of combined subjects remained relatively constant. Comparing intra-individual results over time did not reveal a strong correlation among visits (r = 0.19, 0.50, 0.63 betwe