Demond A, Adriaens P, Towey T, Chang S C, Hong B, Chen Q, Chang C W, Franzblau A, Garabrant D, Gillespie B, Hedgeman E, Knutson K, Lee C Y, Lepkowski J, Olson K, Ward B, Zwica L, Luksemburg W, Maier M
Department of Civil and Environmental Engineering, University of Michigan College of Engineering, Ann Arbor, Michigan 48109, USA.
Environ Sci Technol. 2008 Aug 1;42(15):5441-8. doi: 10.1021/es702554g.
The University of Michigan dioxin exposure study was undertaken to address concerns that the industrial discharge of dioxin-like compounds in the Midland, MI area had resulted in contamination of soils in the Tittabawassee River floodplain and downwind of the incinerator. The study was designed in a rigorously statistical manner comprising soil measurements of 29 polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) from 766 residential properties, selected probabilistically, in the Midland area and in Jackson and Calhoun Counties (Michigan) as a background comparison. A statistical comparison determined that the geometric mean toxic equivalent (TEQ) levels in samples from the target populations were statistically significantly above background. In addition, the probabilities of being above the 75th and 95th percentiles of background were also greater. Congener contributions to the TEQ were dominated by 2,3,4,7,8-PeCDF and 2,3,7,8-TCDF in the floodplain and by 2,3,7,8-TCDD in the incinerator plume. However, PCB 126 was the top congener contributing to the background TEQ. On the basis of statistical inference to the total population, it was estimated that about 36% of the properties in the floodplain and incinerator plume have at least one soil sample over the Michigan Department of Environmental Quality's soil direct contact criterion of 90 pg/g TEQ.
密歇根大学进行二噁英暴露研究，旨在解决人们对密歇根州米德兰地区工业排放二噁英类化合物导致提塔瓦西河泛滥平原土壤以及焚烧炉下风向土壤受到污染的担忧。该研究采用严格的统计方式设计，对米德兰地区以及杰克逊县和卡尔霍恩县（密歇根州）766处通过概率抽样选定的住宅物业的土壤进行测量，检测29种多氯代二苯并 - p - 二噁英（PCDDs）、多氯代二苯并呋喃（PCDFs）和多氯联苯（PCBs）。统计比较确定，目标人群样本中的几何平均毒性当量（TEQ）水平在统计学上显著高于背景值。此外，高于背景值第75和第95百分位数的概率也更高。在泛滥平原，对TEQ贡献最大的同系物是2,3,4,7,8 - 五氯代二苯并呋喃和2,3,7,8 - 四氯代二苯并呋喃，在焚烧炉羽流中则是2,3,7,8 - 四氯代二苯并二噁英。然而，多氯联苯126是对背景TEQ贡献最大的同系物。基于对总体的统计推断，估计泛滥平原和焚烧炉羽流中约36%的物业至少有一个土壤样本超过密歇根环境质量部90 pg/g TEQ的土壤直接接触标准。
