为了对制订空气、水或食品中某种环境污染物的最高容许水平作出决策,必须从该污染物对敏感人群产生显著危险度的暴露水平为依据。总的来说,假如暴露于一种污染物后,细胞内该污染物浓度增高,且累积的细胞损害导致疾病或死亡,则任何污染物均可造成危害。为此需制订环境法规,使暴露降至能防止危害健康的水平。美国正在为许多种污染物制订饮用水条例,已知其中某些污染物对实验动物致癌。对挥发性有机化合物(VOC)现正进行评价,以便制订国家饮水标准。这时需要估算人体对饮水中VOC的暴露水平及其引起 In order to make a decision on the maximum allowable level for the establishment of an environmental pollutant in air, water or foodstuffs, the level of exposure to which the pollutant has a significant risk to sensitive populations must be based on. In general, any contaminant can be hazardous if, after exposure to a contaminant, the concentration of the contaminant increases in the cell and the cumulative cellular damage results in disease or death. To this end, environmental regulations need to be set up to reduce exposure to levels that prevent health hazards. The United States is developing drinking water regulations for many types of pollutants, some of which are known to cause cancer in laboratory animals. Volatile organic compounds (VOCs) are now being evaluated for the development of national drinking water standards. At this time need to estimate the body’s exposure to VOC levels in drinking water and its cause