López-Vázquez Javier, Rodil Rosario, Trujillo-Rodríguez María J, Quintana José Benito, Cela Rafael, Miró Manuel
Department of Analytical Chemistry, Institute of Research on Chemical and Biological Analysis (IAQBUS), Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Galicia, Spain.
Department of Analytical Chemistry, Institute of Research on Chemical and Biological Analysis (IAQBUS), Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Galicia, Spain.
Sci Total Environ. 2022 Jun 20;826:154027. doi: 10.1016/j.scitotenv.2022.154027. Epub 2022 Feb 23.
Notwithstanding the fact that microplastic fragments were encountered in the human stool, little effort has been geared towards elucidating the impact of chemical additives upon the human health. In this work, standardized bioaccessibility tests under both fasting and fed conditions are herein applied to the investigation of human oral bioaccessibility of plastic additives and monomers (i.e. eight phthalate esters (PAEs) and bisphenol A (BPA)) in low-density polyethylene (LDPE) and polyvinyl chloride (PVC) microplastics. The generation of phthalate monoesters is evaluated in the time course of the bioaccessibility tests. Maximum gastric and gastrointestinal bioaccessibility fractions are obtained for dimethyl phthalate, diethyl phthalate and BPA, within the range of 55-83%, 40-68% and 37-67%, respectively, increasing to 56-92% and 41-70% for dimethyl phthalate and diethyl phthalate, respectively, whenever their hydrolysis products are considered. Bioaccessibility fractions of polar PAEs are dependent upon the physicochemical characteristics of the microplastics, with greater bioaccessibility for the rubbery polymer (LDPE). With the method herein proposed, oral bioaccessible pools of moderately to non-polar PAEs can be also accurately assessed for risk-assessment explorations, with values ranging from 1.8% to 32.2%, with again significantly larger desorption percentages for LDPE. Our results suggested that the highest gastric/gastrointestinal bioaccessibility of the eight PAEs and BPA is reached under fed-state gastrointestinal extraction conditions because of the larger amounts of surface-active biomolecules. Even including the bioaccessibility factor within human risk assessment/exposure studies to microplastics, concentrations of dimethyl phthalate, di-n-butyl phthalate and BPA exceeding 0.3% (w/w) may pose severe risks after oral uptake in contrast to the more hydrophobic congeners for which concentrations above 3% (w/w), except for diethylhexyl phthalate, would be tolerated.
尽管在人类粪便中发现了微塑料碎片，但在阐明化学添加剂对人体健康的影响方面所做的努力却很少。在这项工作中，将禁食和进食条件下的标准化生物可及性测试应用于研究低密度聚乙烯（LDPE）和聚氯乙烯（PVC）微塑料中塑料添加剂和单体（即八种邻苯二甲酸酯（PAEs）和双酚A（BPA））的人体口服生物可及性。在生物可及性测试的时间过程中评估邻苯二甲酸单酯的生成。邻苯二甲酸二甲酯、邻苯二甲酸二乙酯和双酚A的最大胃和胃肠道生物可及性分数分别在55-83%、40-68%和37-67%范围内，若考虑其水解产物，邻苯二甲酸二甲酯和邻苯二甲酸二乙酯的最大胃和胃肠道生物可及性分数分别增至56-92%和41-70%。极性PAEs的生物可及性分数取决于微塑料的物理化学特性，橡胶状聚合物（LDPE）的生物可及性更高。使用本文提出的方法，还可以准确评估中度至非极性PAEs的口服生物可及性池，用于风险评估探索，其值范围为1.8%至32.2%，LDPE的解吸百分比再次显著更高。我们的结果表明，由于表面活性生物分子数量较多，在进食状态下的胃肠道提取条件下，八种PAEs和BPA的胃/胃肠道生物可及性最高。即使在人体对微塑料的风险评估/暴露研究中纳入生物可及性因素，与疏水性更强的同系物相比，邻苯二甲酸二甲酯、邻苯二甲酸二正丁酯和双酚A的浓度超过0.3%（w/w）在口服摄入后可能会带来严重风险，对于疏水性更强的同系物，除了邻苯二甲酸二己酯外，浓度高于3%（w/w）是可以耐受的。
