O'Rourke M K, Rogan S P, Jin S, Robertson G L
Environmental and Occupational Health, Arizona Prevention Center, The University of Arizona, Tucson 85721-0468, USA.
J Expo Anal Environ Epidemiol. 1999 Sep-Oct;9(5):446-55. doi: 10.1038/sj.jea.7500050.
Within the context of the National Human Exposure Assessment Survey (NHEXAS), metals were evaluated in the air, soil, dust, water, food, beverages, and urine of a single respondent. Potential doses were calculated for five metals including arsenic. In this paper, we seek to validate the potential dose calculations through spatial analysis of the data. Others report elevated arsenic concentrations in biological and environmental samples from residents of mining towns, particularly Ajo, Arizona. These reports led us to expect potential arsenic doses above the 90th percentile of the NHEXAS exposure distribution to be from residents of mining communities. Arsenic dose was calculated using media concentrations, time activity patterns, and published exposure factors. Of the 179 homes evaluated, 54 were in mining communities; 11 of these were considered separately for reasons of population bias. Of the 17 homes with the greatest potential arsenic doses, almost half (47%) were in mining communities. We evaluated the potential doses by media from nonmining and mining areas using the nonparametric Mann-Whitney U test. Statistically significant (p = 0.05) differences were found between mining (n = 43) and nonmining sites (n = 122) for total exposure and for each of the following media: house dust, yard soil, outdoor air, beverage consumed, and water consumed. No differences were found in either food or indoor air of mining and nonmining areas. We eliminated outliers and repeated the test for all media; significance increased. Dietary, organic arsenic from fish consumption contributed to elevated arsenic exposure among people from nonmining communities and acted as an initial confounder. When controlling for fish consumption, we were able to validate our potential dose model using arsenic, particularly in Ajo. Further, we identified three mining communities lacking elevated arsenic exposure. Additional work is needed speciating the arsenic and evaluating health risks. The utilization of Geographic Information System facilitated spatial this project and paves the way for more sophisticated future spatial analyses.
在美国国家人类暴露评估调查（NHEXAS）的背景下，对一名受访者的空气、土壤、灰尘、水、食物、饮料和尿液中的金属进行了评估。计算了包括砷在内的五种金属的潜在剂量。在本文中，我们试图通过对数据的空间分析来验证潜在剂量的计算。其他人报告说，采矿城镇居民的生物和环境样本中砷浓度升高，特别是亚利桑那州的阿霍。这些报告使我们预计，NHEXAS暴露分布第90百分位数以上的潜在砷剂量来自采矿社区的居民。砷剂量是根据介质浓度、时间活动模式和公布的暴露因子计算的。在评估的179所房屋中，54所位于采矿社区；由于人口偏差，其中11所被单独考虑。在潜在砷剂量最高的17所房屋中，几乎一半（47%）位于采矿社区。我们使用非参数曼-惠特尼U检验评估了非采矿区和采矿区各介质的潜在剂量。在采矿区（n = 43）和非采矿区（n = 122）之间，总暴露量以及以下每种介质：房屋灰尘、庭院土壤、室外空气、饮用饮料和饮用水，均发现有统计学显著差异（p = 0.05）。在采矿区和非采矿区的食物或室内空气中均未发现差异。我们剔除了异常值，并对所有介质重复进行了测试；显著性增加。来自鱼类消费的膳食有机砷导致非采矿社区居民的砷暴露升高，并起到了初始混杂因素的作用。在控制鱼类消费后，我们能够使用砷验证我们的潜在剂量模型，特别是在阿霍。此外，我们确定了三个砷暴露未升高的采矿社区。还需要开展更多工作来确定砷的种类并评估健康风险。地理信息系统的应用促进了该项目的空间分析，并为未来更复杂的空间分析铺平了道路。
