Twerdok L E
Health and Environmental Sciences Department, American Petroleum Institute, NW, Washington, DC 20005, USA.
Drug Chem Toxicol. 1999 Feb;22(1):275-91. doi: 10.3109/01480549909029736.
The Total Petroleum Hydrocarbon Criteria Working Croup (TPHCWG) was formed in 1993 based on the observation that widely different clean-up requirements were being used by states at sites that were contaminated with hydrocarbon materials such as fuels, lubricating oils, and crude oils. These requirements were usually presented as concentration of total petroleum hydrocarbon (TPH), and ranged from 10 to over 10,000 mg TPH/kg soil. Members of this multi-disciplinary group, consisting of representatives from industry, government and academia, jointly recognized that the numerical standard was not based on a scientific assessment of human health risk and established the following goal for the effort: To develop scientifically defensible information for establishing soil cleanup levels that are protective of human health at hydrocarbon contaminated sites. The approach developed by the TPHCWG for TPH hazard assessment consisted of dividing the petroleum hydrocarbon material into multichemical-containing fractions with similar fate and transport characteristics. These fractions were then assigned fate and transport properties (volatilization factor, soil leaching factor, etc.) and toxicity values (RfDs/RfCs) representative of the fraction. The actual site specific hazard assessment and derivation of cleanup levels is accomplished by analyzing sites to determine which fraction(s) is present and applying the appropriate fate, transport and toxicity factors. The method used by this group to determine TPH Faction specific toxicity criteria is a surrogate approach intended to supplement the indicator approach. Indicators are single, carcinogenic hydrocarbon compounds which are evaluated/regulated individually at either the federal or state level. The TPHCWG surrogate approach utilized all appropriate fraction specific toxicity data (single compound and mixture/product), minus the carcinogenic indicator compounds, to derive the fraction specific RfDs and RfCs. This hazard assessment method for petroleum contaminated sites would be utilized where indicator compounds are not present or are below/remediated to regulatory action levels. Derivation of the RfD/RfC values for the n-hexane containing aliphatic C5-C8 fraction is examined in detail to illustrate the underlying assumptions and use of existing data employed by the TPHCWG to develop fraction specific toxicity criteria. Toxicity RfDs/RfCs for all of the model fate and transport based fractions are also presented.
总石油烃标准工作组（TPHCWG）成立于1993年，当时观察到各州在受燃料、润滑油和原油等碳氢化合物材料污染的场地采用了差异很大的清理要求。这些要求通常以总石油烃（TPH）浓度表示，范围从10到超过10000毫克TPH/千克土壤。这个多学科小组的成员包括来自行业、政府和学术界的代表，他们共同认识到数值标准并非基于对人类健康风险的科学评估，并为这项工作确立了以下目标：开发科学上站得住脚的信息，以确定碳氢化合物污染场地保护人类健康的土壤清理水平。TPHCWG制定的TPH危害评估方法包括将石油烃材料分为具有相似归宿和迁移特性的多化学组分。然后为这些组分赋予代表该组分的归宿和迁移特性（挥发因子、土壤淋溶因子等）以及毒性值（参考剂量/参考浓度）。实际的特定场地危害评估和清理水平推导是通过分析场地以确定存在哪些组分，并应用适当的归宿、迁移和毒性因子来完成的。该小组用于确定TPH组分特定毒性标准的方法是一种替代方法，旨在补充指标方法。指标是单一的致癌碳氢化合物，在联邦或州层面单独进行评估/监管。TPHCWG替代方法利用所有适当的组分特定毒性数据（单一化合物和混合物/产品），减去致癌指标化合物，以得出组分特定的参考剂量和参考浓度。这种石油污染场地的危害评估方法将在不存在指标化合物或指标化合物低于/已修复至监管行动水平的情况下使用。详细研究了含正己烷的脂肪族C5 - C8组分的参考剂量/参考浓度值的推导，以说明TPHCWG用于制定组分特定毒性标准的基本假设和现有数据的使用情况。还列出了所有基于模型归宿和迁移的组分的毒性参考剂量/参考浓度。
