作为国家人类暴露评估调查的一部分， 采用多阶段抽样进行估计和比较 两年饮用水相关的暴露和风险 群体——亚利桑那州和边境社区的人口。 有人担心边境社区的 风险敞口将高于该州其他地区的风险敞口 因为他们靠近墨西哥，那里的环境质量 这可能不像在美国那么重要。 这两个研究人群进一步按性别分类， 年龄、种族、教育、收入和建筑结构类型 建设年份。对于这些亚组，该研究估计 比较了砷、1,3-丁二烯、氯仿、铬、， 1,2-二氯乙烷、二氯甲烷、铅、镍和甲苯。对于 几乎所有样本受试者的残留物浓度均为 低于亚利桑那州和 美国环境保护署。在所研究的金属中， 砷是唯一一种人群致癌风险高于此的物质 1.0E-6的可接受水平。与表达的担忧相反， 平均每日暴露和相关风险估计为 边境社区的人口比亚利桑那州的人口要少。 对于公用事业，一个值得进一步研究的发现是 据估计，来自自来水的风险大于来自 不沾水。进一步的研究可能有助于揭示 这些风险升高的原因。包括26个参考文献、表格和图表。

As part of the National Human Exposure Assessment Survey, a multistage sampling was used to estimate and compare exposures and risks associated with drinking water for two groups - the population of Arizona and that of border communities. There had been some concern that the border communities' exposures would be higher than those of other parts of the state because of their proximity to Mexico, where environmental quality may not be as high a priority as it is in the United States. The two study populations were further categorized by gender, age, ethnicity, education, income, and building structure type and year of construction. For these subgroups, the study estimated and compared risks for arsenic, 1,3-butadiene, chloroform, chromium, 1,2-dichloroethane, dichloromethane, lead, nickel, and toluene. For almost all of the sample subjects, residue concentrations were below the drinking water guideline values of both Arizona and the US Environmental Protection Agency. Of the metals studied, arsenic was the only one with a population carcinogenic risk above the acceptable level of 1.0E-6. Contrary to expressed concerns, average daily exposures and associated risks were estimated to be smaller in the border communities than in the Arizona population. For utilities, one finding deserving further study was that risks from tap water were estimated to be greater than risks from nontap water. Further research may be warranted to uncover the causes for these elevated risks. Includes 26 references, tables, figure.