Cancer Risk Assessment of Polycyclic Aromatic Hydrocarbon Contaminated Soils Determined Using Bioassay-Derived Levels of Benzo[a]pyrene Equivalents

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• 作者：Christine L. Lemieux ; Alexandra S. Long ; Iain B. Lambert ; Staffan Lundstedt ; Mats Tysklind ; Paul A. White
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：February 3, 2015
• 年：2015
• 卷：49
• 期：3
• 页码：1797-1805
• 全文大小：290K
• ISSN：1520-5851

文摘

Here we evaluate the excess lifetime cancer risk (ELCR) posed by 10 PAH-contaminated soils using (i) the currently advocated, targeted chemical-specific approach that assumes dose additivity for carcinogenic PAHs and (ii) a bioassay-based approach that employs the in vitro mutagenic activity of the soil fractions to determine levels of benzo[a]pyrene equivalents and, by extension, ELCR. Mutagenic activity results are presented in our companion paper.1 The results show that ELCR values for the PAH-containing fractions, determined using the chemical-specific approach, are generally (i.e., 8 out of 10) greater than those calculated using the bioassay-based approach; most are less than 5-fold greater. Only two chemical-specific ELCR estimates are less than their corresponding bioassay-derived values; differences are less than 10%. The bioassay-based approach, which permits estimation of ELCR without a priori knowledge of mixture composition, proved to be a useful tool to evaluate the chemical-specific approach. The results suggest that ELCR estimates for complex PAH mixtures determined using a targeted, chemical-specific approach are reasonable, albeit conservative. Calculated risk estimates still depend on contentious PEFs and cancer slope factors. Follow-up in vivo mutagenicity assessments will be required to validate the results and their relevance for human health risk assessment of PAH-contaminated soils.