Fremlin Kate M, Berg Nicole, Gobas Frank A P C
Simon Fraser University, Dept. of Biological Sciences, 8888 University Drive, Burnaby, BC V5A 1S6, Canada.
School of Resource and Environmental Management, Faculty of the Environment, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
Sci Total Environ. 2025 Jun 1;979:179368. doi: 10.1016/j.scitotenv.2025.179368. Epub 2025 Apr 27.
Many industrial substances cannot be assessed for their bioaccumulation potential using the octanol-water partition coefficient (K), bioconcentration factor (BCF), or bioaccumulation factor (BAF) criteria typically used in the United Nations Stockholm Convention for Persistent Organic Pollutants (POPs) and in regulations and laws of many countries including Canada, the European Union (EU), the United States (US), and Japan. This presents an impediment to an efficient, effective, and expedient environmental assessment of many substances. However, the Stockholm Convention includes a second criterion for bioaccumulation assessments that is focussed on "Evidence that a chemical presents other reasons for concern, such as high bio-accumulation in other species, high toxicity, or ecotoxicity." But this criterion has received little attention; is not recognized or used in national regulations; and lacks a framework for evaluation. This study investigates the application of this second criterion to (i) assess the bioaccumulation potential of difficult-to-test and difficult-to-evaluate substances that cannot be adequately evaluated with K, BCF, or BAF due to very low aqueous solubility, ionization poor solubility in lipids, large molecular size, or other reasons; and (ii) present and test a framework for bioaccumulation assessments that aims to determine whether substances bioaccumulate to levels of concern. The framework is tested using evidence of bioaccumulation for decabromodiphenyl ethane (DBDPE; CAS: 84852-53-9), which is a super-hydrophobic substance that is difficult to test in aqueous and dietary bioaccumulation tests. To evaluate DBDPE with this framework, we compiled bioaccumulation and toxicological data from the published literature, evaluated the exposure concentration data for quality, and applied a chemical activity-based evaluation. Our results indicate that based on available information to date, DBDPE does not appear to bioaccumulate to levels of concern that would affect environmental health at a global or local scale. The results also suggest that our evaluative framework may be a useful alternative for other super-hydrophobic and/or ionizing substances like perfluoroalkyl and polyfluoroalkyl substances and/or aromatic brominated flame retardants that cannot be assessed for bioaccumulation potential based on K, BCF, or BAF.
许多工业物质无法依据联合国《关于持久性有机污染物的斯德哥尔摩公约》以及包括加拿大、欧盟、美国和日本在内的许多国家的法规中通常使用的辛醇 - 水分配系数（K）、生物浓缩系数（BCF）或生物累积系数（BAF）标准来评估其生物累积潜力。这给许多物质的高效、有效且便捷的环境评估带来了阻碍。然而，《斯德哥尔摩公约》包含了生物累积评估的第二个标准，该标准侧重于“有证据表明一种化学物质存在其他令人担忧的原因，例如在其他物种中的高生物累积性、高毒性或生态毒性”。但这一标准很少受到关注；在国家法规中未得到认可或使用；并且缺乏评估框架。本研究调查了这第二个标准的应用，以（i）评估因水溶性极低、脂溶性差、分子量大或其他原因而无法用K、BCF或BAF进行充分评估的难以测试和评估的物质的生物累积潜力；以及（ii）提出并测试一个生物累积评估框架，该框架旨在确定物质是否生物累积到令人担忧的水平。使用十溴二苯醚（DBDPE；化学物质登记号：84852 - 53 - 9）的生物累积证据对该框架进行了测试，DBDPE是一种超疏水物质，在水性和膳食生物累积测试中难以测试。为了用这个框架评估DBDPE，我们从已发表的文献中收集了生物累积和毒理学数据，评估了暴露浓度数据的质量，并应用了基于化学活性的评估。我们的结果表明，基于目前可用的信息，DBDPE似乎不会生物累积到会在全球或局部尺度上影响环境健康的令人担忧水平。结果还表明，我们的评估框架对于其他超疏水和/或电离物质，如全氟烷基和多氟烷基物质以及/或芳香族溴化阻燃剂，可能是一种有用的替代方法，这些物质无法基于K、BCF或BAF评估其生物累积潜力。
