Geiger Stephen C, Azzolina Nicholas A, Nakles David V, Hawthorne Steven B
ERM, Washington DC, USA.
The CETER Group, Green Bay, Wisconsin, USA.
Integr Environ Assess Manag. 2016 Jul;12(3):493-9. doi: 10.1002/ieam.1700. Epub 2015 Oct 17.
Polycyclic aromatic hydrocarbons (PAHs) are major drivers of risk at many urban and/or industrialized sediment sites. The US Environmental Protection Agency (USEPA) currently recommends using measurements of 18 parent + 16 groups of alkylated PAHs (PAH-34) to assess the potential for sediment-bound PAHs to impact benthic organisms at these sites. ASTM Method D7363-13 was developed to directly measure low-level sediment porewater PAH concentrations. These concentrations are then compared to ambient water criteria (final chronic values [FCVs]) to assess the potential for impact to benthic organisms. The interlaboratory validation study that was used to finalize ASTM D7363-13 was developed using 24 of the 2-, 3-, and 4-ring PAHs (PAH-24) that are included in the USEPA PAH-34 analyte list. However, it is the responsibility of the user of ASTM Method D7363 to establish a test method to quantify the remaining 10 higher molecular weight PAHs that make up PAH-34. These higher molecular weight PAHs exhibit extremely low saturation solubilities that make their detection difficult in porewater, which has proven difficult to implement in a contract laboratory setting. As a result, commercial laboratories are hesitant to conduct the method on the entire PAH-34 analyte list. This article presents a statistical comparison of the ability of the PAH-24 and PAH-34 porewater results to predict survival of the freshwater amphipod Hyalella azteca, using the original 269 sediment samples used to gain ASTM D7363 Method approval. The statistical analysis shows that the PAH-24 are statistically indistinguishable from the PAH-34 for predicting toxicity. These results indicate that the analysis of freely dissolved porewater PAH-24 is sufficient for making risk-based decisions based on benthic invertebrate toxicity (survival and growth). This reduced target analyte list should result in a cost-saving for stakeholders and broader implementation of the method at PAH-impacted sediment sites. Integr Environ Assess Manag 2016;12:493-499. © 2015 SETAC.
多环芳烃（PAHs）是许多城市和/或工业化沉积物场地风险的主要驱动因素。美国环境保护局（USEPA）目前建议使用18种母体+16组烷基化多环芳烃（PAH-34）的测量值来评估沉积物结合的多环芳烃对这些场地底栖生物产生影响的可能性。ASTM方法D7363-13旨在直接测量沉积物孔隙水中低水平的多环芳烃浓度。然后将这些浓度与环境水标准（最终慢性值[FCVs]）进行比较，以评估对底栖生物产生影响的可能性。用于最终确定ASTM D7363-13的实验室间验证研究是使用USEPA PAH-34分析物列表中包含的24种二环、三环和四环多环芳烃（PAH-24）开展的。然而，ASTM方法D7363的用户有责任建立一种测试方法，以量化构成PAH-34的其余10种较高分子量的多环芳烃。这些较高分子量的多环芳烃具有极低的饱和溶解度，使得它们在孔隙水中难以检测，这已证明在合同实验室环境中难以实施。因此，商业实验室对按照整个PAH-34分析物列表进行该方法测定犹豫不决。本文使用最初用于获得ASTM D7363方法批准的269个沉积物样品，对PAH-24和PAH-34孔隙水结果预测淡水双壳类动物阿氏摇蚊（Hyalella azteca）存活能力进行了统计比较。统计分析表明，在预测毒性方面，PAH-24与PAH-34在统计学上没有区别。这些结果表明，基于底栖无脊椎动物毒性（存活和生长）进行基于风险的决策时，对自由溶解的孔隙水PAH-24进行分析就足够了。这种减少的目标分析物列表应能为利益相关者节省成本，并在受多环芳烃影响的沉积物场地更广泛地实施该方法。《综合环境评估与管理》2016年；12：493-499。©2015 SETAC。
