Parent and alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs), which are a class of important toxic components of crude oil especially in the marine environment, exhibit adverse effects on aquatic life and potentially pose a human health risk. However, the lack of chronic toxicity data is one of the hindrances for alkyl-PAHs when assessing their ecological risks. In this study, predicted no-effect concentrations (PNECs) in seawater and marine sediment for ten parent- and alkyl-PAHs were derived by applying species sensitivity distributions (SSDs) and quantitative structure-activity relationships (QSARs). The local area, Dalian Bay, where an oil-spilled accident happened in 2010, was chosen as a case site to assess ecological risks for ten PAHs in surface seawaters and marine sediments. Their PNECs in seawater and sediment for protecting aquatic organisms in marine ecosystems were calculated and recommended in the range of 0.012–2.79 μg/L and 48.2–1 337 ng/g (dry weight), respectively. Overall, the derived PNECs for the studied PAHs in seawater and marine sediment were comparable to those obtained by classical methods. Risk quotient results indicate low ecological risks to ecosystems for ten parent- and alkyl-PAHs in surface seawaters and surface sediments from the Dalian Bay. These findings provide a first insight into the PNECs and ecological risks of alkyl-PAHs, emphasizing the role of the computational toxicology in ecological risk assessments. The use of QSARs has been identified as a valuable tool for preliminarily assessing ecological risks of emerging pollutants, being more predictable of real exposure scenarios for risk assessment purposes.

母体和烷基化的多环芳香烃（烷基-PAHs）是一类重要的原油有毒成分，尤其是在海洋环境中，对水生生物产生不利影响，并可能对人类健康构成威胁。但是，缺乏慢性毒性数据是烷基PAHs评估其生态风险时的障碍之一。在这项研究中，通过应用物种敏感度分布（SSD）和定量构效关系（QSAR），推导出了十种母体和烷基PAH的海水和海洋沉积物中的预测无效应浓度（PNEC）。选择2010年发生溢油事故的大连湾为案例，评估地表海水和海洋沉积物中十种多环芳烃的生态风险。用于保护海洋生态系统的海水和沉积物中保护海洋生物的PNECs分别为0.012-2.79μg/ L和48.2-1 337 ng / g（干重）。总体而言，所研究的海水和海洋沉积物中多环芳烃的PNEC与传统方法所获得的PNEC相当。风险商结果表明，大连湾表层海水和表层沉积物中的十种母体和烷基多环芳烃对生态系统的生态风险较低。这些发现为PNECs和烷基PAHs的生态风险提供了初步见解，强调了计算毒理学在生态风险评估中的作用。QSAR的使用已被认为是初步评估新兴污染物的生态风险的宝贵工具，