State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
Environ Int. 2023 Feb;172:107795. doi: 10.1016/j.envint.2023.107795. Epub 2023 Feb 4.
Perfluoroalkyl acids (PFAAs) are contaminants of global concern, and the inadvertent consumption of PFAA-contaminated crops may pose a threat to public health. Therefore, systematically studying their source tracing, bioaccumulation prediction and risk assessments in crops is an urgent priority. This study investigated the source apportionment and transport of PFAAs and novel fluorinated alternatives (collectively as per- and polyfluoroalkyl substances, PFASs) from factories to agricultural fields in a fluorochemical industrial region of China. Furthermore, bioaccumulation specificities and prediction of these chemicals in different vegetables were explored, followed by a comprehensive risk assessment from agricultural fields to dinner plates which considered precursor degradation. A positive matrix factorization model revealed that approximately 70 % of PFASs in agricultural soils were derived from fluorochemical manufacturing and metal processing. Alarming levels of ∑PFASs ranged 8.28-84.3 ng/g in soils and 163-7176 ng/g in vegetables. PFAS with short carbon chain or carboxylic acid group as well as branched isomers exhibited higher environmental transport potentials and bioaccumulation factors (BAFs) across a range of vegetables. The BAFs of different isomers of perfluorooctanoic acid (PFOA) decreased as the perfluoromethyl group moved further from the acid functional group. Hexafluoropropylene oxide dimer acid (GenX) showed relatively low BAFs, probably related to its ether bond with a high affinity to soil. Vegetables with fewer Casparian strips (e.g., carrot and radish), or more protein, possessed larger BAFs of PFASs. A bioaccumulation equation integrating critical parameters of PFASs, vegetables and soils, was built and corroborated with a good contamination prediction. After a total oxidizable precursors (TOP) assay, incremental perfluoroalkyl carboxylic acids (PFCAs) were massively found (325-5940 ng/g) in edible vegetable parts. Besides, precursor degradation and volatilization loss of PFASs was firstly confirmed during vegetable cooking. A risk assessment based on the TOP assay was developed to assist the protection of vegetable consumers.
全氟烷基酸（PFAAs）是全球性关注的污染物，而无意中摄入被 PFAA 污染的农作物可能会对公众健康构成威胁。因此，系统地研究它们在农作物中的溯源、生物累积预测和风险评估是当务之急。本研究调查了中国氟化工产业区工厂到农田的 PFAAs 和新型含氟替代品（统称全氟和多氟烷基物质，PFASs）的来源分配和迁移。此外，还探索了这些化学物质在不同蔬菜中的生物累积特异性和预测，并从农田到餐盘考虑前体降解进行了综合风险评估。正矩阵因子分解模型显示，农田土壤中约 70%的 PFASs 来自氟化工制造和金属加工。土壤中∑PFASs 的浓度范围为 8.28-84.3ng/g，蔬菜中浓度范围为 163-7176ng/g。短链或羧酸基团以及支化异构体的 PFAS 表现出更高的环境迁移潜力和生物累积因子（BAFs），在各种蔬菜中均如此。全氟辛酸（PFOA）不同异构体的 BAF 随着全氟甲基基团离酸官能团越远而降低。六氟丙烯氧化物二聚酸（GenX）表现出相对较低的 BAF，可能与其与土壤具有高亲和力的醚键有关。具有较少凯氏带（如胡萝卜和萝卜）或更多蛋白质的蔬菜，对 PFASs 的 BAF 更大。建立了一个整合 PFASs、蔬菜和土壤关键参数的生物累积方程，并通过良好的污染预测进行了验证。在总可氧化前体（TOP）试验后，在可食用蔬菜部分中大量发现（325-5940ng/g）可氧化的全氟烷基羧酸（PFCAs）。此外，首次确认了 PFASs 在蔬菜烹饪过程中的前体降解和挥发损失。基于 TOP 试验的风险评估被开发出来，以协助保护蔬菜消费者。
