Fluorochemicals in AFFF-contaminated sites: environmental fate, toxicity and treatment

几十年来，全氟烷基和多氟烷基物质（PFAS）的使用已导致对人类、野生动物和环境的严重污染。一些PFAS在环境中具有极强的持久性，并表现出很高的生物累积潜力和毒性。这种污染的最严重形式主要与使用基于PFAS的水性成膜泡沫（AFFF）进行灭火活动有关，影响了加拿大数百个联邦污染地点的地下水、地表水、土壤和沉积物。由于尚未对AFFF污染状况进行具体调查，因此管理AFFF污染场地的监管框架基本上不存在。PFAS独特的物理、化学和生物学特性给解决这一问题带来了巨大的挑战。监管机构和环保顾问都在问：在AFFF影响的场地中存在哪些类型的PFAS，以及哪些浓度会对环境造成风险？PFAS如何在不同的自然和工程条件下以及在其他污染物存在下运输和转化？可以实施哪些经济高效的风险迁移技术？我们的研究旨在回答这些问题，通过详细描述现场污染样品，实验室研究PFAS在土壤和地下水系统中的环境归宿和行为，评估主要PFAS的生物累积潜力，并开发一种创新的基于纳米技术的PFAS去除修复方法。这项研究将由一组国际公认的研究人员进行，他们在环境工程、化学和微生物学以及生态毒理学方面具有互补的专业知识。我们的研究结果将有助于监管机构和风险评估专家制定有关AFFF使用，处置，风险评估和补救的政策，法规或指南。拟议的研究具有重要的经济效益，加拿大优化资源，以达到降低风险的目标，具有成本效益，并通过提高技术专长，在私营部门在环境风险评估和补救领域。

The use of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in decades has led to widespreadcontamination in humans, wildlife and the environment. Some PFAS are extremely persistent in theenvironment and exhibit high bioaccumulation potential and toxicity. The most severe form of this pollution isprimarily associated with the use of PFAS-based aqueous film-forming foams (AFFFs) for firefightingactivities, impacting groundwater, surface water, soil and sediment in several hundred federal contaminatedsites across Canada. As the state of AFFF contamination has not been specifically investigated, regulatoryframeworks for managing AFFF-contaminated sites largely do not exist. Unique physical, chemical andbiological properties of PFAS pose great challenges for addressing the issue. Regulatory bodies andenvironmental consultants are asking: what types of PFAS are present in AFFF-impacted sites and whatconcentrations pose risks to the environment? How do PFAS transport and transform under varying natural andengineered conditions and in the presence of other contaminants? What cost-effective risk migrationtechnologies can be implemented? Our research is aimed at answering these questions through detailedcharacterization of field contaminated samples, laboratory studies on the environmental fate and behaviours ofPFAS in soil and groundwater systems, evaluating bioaccumulation potential of major PFAS, and developingan innovative nanotechnology-based remediation approach for PFAS removal. The research will be conductedby a group of internationally recognized researchers with complementary expertise in environmentalengineering, chemistry and microbiology, and ecotoxicology. Results from our research will helpenvironmental regulators and risk assessment experts develop policies, regulations or guidelines on AFFF use,disposal, risk assessment and remediation. The proposed research has important economic benefits to Canadaby optimizing resources to reach risk mitigation goals cost-effectively and by enhancing technical expertise inthe private sector in the area of environmental risk assessment and remediation.