Abstract:
Perfluoroalkyl substances (PFAS) are common environmental pollutants, but their toxicity framework remains elusive. This research focused on ten PFAS, evaluating their impacts on two ecotoxicologically relevant model organisms from distinct trophic levels: the crustacean Daphnia magna and the unicellular green alga Raphidocelis subcapitata. The results showed a greater sensitivity of R. subcapitata compared to D. magna. However, a 10-day follow-up to the 48 h immobilisation test in D. magna showed delayed mortality, underlining the limitations of relying on EC50 s from standard acute toxicity tests. Among the compounds scrutinized, Perfluorodecanoic acid (PFDA) was the most toxic to R. subcapitata, succeeded by Perfluorooctane sulfonate (PFOS), Perfluorobutanoic acid (PFBA), and Perfluorononanoic acid (PFNA), with the latter being the only one to show an algicidal effect. In the same species, assessment of binary mixtures of the compounds that demonstrated high toxicity in the single evaluation revealed either additive or antagonistic interactions. Remarkably, with an EC50 of 31 mg L-1, the short-chain compound PFBA, tested individually, exhibited toxicity levels akin to the notorious long-chain PFOS, and its harm to freshwater ecosystems cannot be ruled out. Despite mounting toxicological evidence and escalating environmental concentrations, PFBA has received little scientific attention and regulatory stewardship. It is strongly advisable that regulators re-evaluate its use to mitigate potential risks to the environmental and human health.
摘要:
全氟烷基物质(PFAS)是常见的环境污染物,但它们的毒性框架仍然难以捉摸。本研究集中于十种PFAS,从不同的营养水平评估它们对两种生态毒理学相关模型生物的影响:甲壳类大型水蚤和单细胞绿藻Raphidocelissubcapital。结果表明,与D.magna相比,头下R.的敏感性更高。然而,在D.magna中对48h固定测试进行10天的随访显示延迟死亡,强调依赖标准急性毒性试验中的EC50的局限性。在仔细检查的化合物中,全氟癸酸(PFDA)对头孢酵母毒性最大,由全氟辛烷磺酸(PFOS),全氟丁酸(PFBA),和全氟壬酸(PFNA),后者是唯一表现出杀藻作用的。在同一物种中,对在单一评估中显示高毒性的化合物的二元混合物的评估显示了加性或拮抗性相互作用。值得注意的是,EC50为31毫克L-1,短链化合物PFBA,单独测试,表现出类似于臭名昭著的长链全氟辛烷磺酸的毒性水平,不能排除其对淡水生态系统的危害。尽管有越来越多的毒理学证据和不断升级的环境浓度,PFBA很少受到科学关注和监管管理。强烈建议监管机构重新评估其用途,以减轻对环境和人类健康的潜在风险。