Stantec Consulting, Guelph, Ontario, Canada.
Environ Toxicol Chem. 2012 Nov;31(11):2536-44. doi: 10.1002/etc.1974. Epub 2012 Aug 29.
Ecological tier 1 Canada-wide standards (CWS) for petroleum hydrocarbon (PHC) fraction 2 (F2; >nC10-C16) in soil were derived using ecotoxicological assessment endpoints (effective concentrations [ECs]/lethal concentrations [LCs]/inhibitory concentrations, 25% [IC25s]) with freshly spiked (fresh) fine- and coarse-grained soils. These soil standards might be needlessly conservative when applied to field samples with weathered hydrocarbons. The purpose of the present study was to assess the degradation and toxicity of weathered PHC F2 in a fine-grained soil and to derive direct soil contact values for ecological receptors. Fine-grained reference soils were spiked with distilled F2 and weathered for 183 d. Toxicity tests using plants and invertebrates were conducted with the weathered F2-spiked soils. Endpoint EC/IC25s were calculated and used to derive soil standards for weathered F2 in fine-grained soil protective of ecological receptors exposed via direct soil contact. The values derived for weathered F2 were less restrictive than current ecological tier 1 CWS for F2 in soil.
加拿大范围内针对石油烃（PHC）第 2 馏分（F2；>nC10-C16）的生态层次 1 标准（CWS）是使用生态毒理学评估终点（有效浓度[EC]/致死浓度[LC]/抑制浓度，25%[IC25s]），对新添加（新鲜）细粒和粗粒土壤进行推导得出的。当将这些土壤标准应用于风化烃的野外样本时，可能会过于保守。本研究的目的是评估风化 PHC F2 在细粒土壤中的降解和毒性，并为生态受体推导直接土壤接触值。将细粒参考土壤用蒸馏 F2 进行添加，并风化 183 天。使用植物和无脊椎动物进行了风化 F2 污染土壤的毒性测试。计算了终点 EC/IC25s，并用于推导细粒土壤中保护通过直接土壤接触暴露的生态受体的风化 F2 的土壤标准。得出的风化 F2 值比目前针对土壤中 F2 的生态层次 1 CWS 更具限制性。
