Lemieux Christine L, Lambert Iain B, Lundstedt Staffan, Tysklind Mats, White Paul A
Mutagenesis Section, Safe Environments Program, Health Canada, 50 Columbine Drive, Tunney's Pasture 0803A, Ottawa, Ontario K1A 0K9, Canada.
Environ Toxicol Chem. 2008 Apr;27(4):978-90. doi: 10.1897/07-157.1.
The objective of the present study was to evaluate hazard/risk assessment methods for complex environmental mixtures that involve a targeted, priority chemical approach based on the cumulative hazard/risk of known mixture components or analyses of sufficiently similar mixtures. Ten polycyclic aromatic hydrocarbon (PAH)-contaminated soils were separated into nonpolar and semipolar fractions, and both fractions elicited positive responses on the Salmonella reverse mutation assay. Targeted and nontargeted methods of hazard prediction routinely overestimated mutagenic activities for the nonpolar soil fractions, suggesting nonadditive interactions of PAHs in complex mixtures. This suggests that current risk assessment methods for complex mixtures may provide conservative estimates regarding soils contaminated with priority PAHs alone. Significant underestimations of total risk, however, will be obtained if the soils also contain unidentified PAHs as well as polycyclic aromatic compounds and related compounds that contribute to the total mutagenic activity. Furthermore, estimates of excess lifetime cancer risk associated with the nondietary ingestion of the PAH-contaminated soils studied here indicate that a traditional risk assessment model based on identified priority PAHs and an assumption of additivity generally underestimates the risk associated with the nonpolar soil fractions (in comparison to bioassay-derived risk estimates). Additional cancer risk may be associated with the more polar compounds that also are found at these contaminated sites and that rarely are included in the standard risk assessment methodology.
本研究的目的是评估复杂环境混合物的危害/风险评估方法，该方法涉及基于已知混合物成分的累积危害/风险或对足够相似混合物的分析采用针对性的优先化学方法。将十种受多环芳烃（PAH）污染的土壤分离为非极性和半极性部分，这两个部分在沙门氏菌回复突变试验中均产生阳性反应。常规的针对性和非针对性危害预测方法通常高估了非极性土壤部分的诱变活性，这表明多环芳烃在复杂混合物中存在非加性相互作用。这表明，目前针对复杂混合物的风险评估方法可能会对仅受优先多环芳烃污染的土壤提供保守估计。然而，如果土壤中还含有未鉴定的多环芳烃以及对总诱变活性有贡献的多环芳香化合物和相关化合物，则将大大低估总风险。此外，与本文研究的受多环芳烃污染土壤的非膳食摄入相关的终生癌症超额风险估计表明，基于已鉴定的优先多环芳烃和加性假设的传统风险评估模型通常低估了与非极性土壤部分相关的风险（与生物测定得出的风险估计值相比）。额外的癌症风险可能与在这些受污染场地也发现的极性更强的化合物有关，而这些化合物很少包含在标准风险评估方法中。
