南湖新闻网

首页 > 新闻 > 科学研究 > 正文

我校在全氟和多氟化合物的作物富集预测与风险评估中取得新进展

核心提示: 近日,我校资源与环境学院国家环境保护土壤健康诊断与绿色修复重点实验室土壤化学与环境团队在农用地全氟和多氟化合物(PFASs)的来源解析、作物污染预测与健康风险研究中取得重要进展。

南湖新闻网讯(通讯员 刘顺)近日,我校资源与环境学院国家环境保护土壤健康诊断与绿色修复重点实验室土壤化学与环境团队解析了农用地全氟和多氟化合物(PFASs)的污染来源种类及相对贡献,基于多种作物富集特征创建了污染预测模型,并耦合烹饪加热、前体物降解等过程发展了风险评估方法,研究成果以“Transport and transformation of perfluoroalkyl acids, isomer profiles, novel alternatives and unknown precursors from factories to dinner plates in China: New insights into crop bioaccumulation prediction and risk assessment”为题在Environment International发表,该研究为农业种植中新污染物的风险评价与精准管控提供了新思路。

PFASs是一类备受全球关注的新型持久性有机污染物,对人体免疫、内分泌、神经等系统以及胎幼儿生长发育均具有毒性,其有害组分于2022年被列入国务院发布的《新污染物治理行动方案》和生态环境部的《重点管控新污染物清单》。食用受PFASs污染的农作物可对人体健康造成威胁。为有效减少作物污染,降低人群暴露风险,探究农用地PFASs的污染来源与途径,开展作物污染预测并进行健康风险评估势在必行。

图片1

本研究系统解析了农用地中传统和新兴PFASs及其同分异构体、前体物的污染源种类、相对贡献与输入路径,揭示了作物富集能力与PFASs分子结构、土壤性质、植物形态与生理特征的关联机制,创新性地建立了PFASs作物污染预测模型,并结合烹饪加热、前体物降解等过程发展了PFASs人体暴露与健康风险评价的新方法。

基于正交矩阵因子分解模型与污染排放清单的联合分析,发现研究区土壤中约70%的PFASs来源于氟化工制造业和金属加工,大气沉降与地下水灌溉是其重要输入途径。不同种类蔬菜对土壤中PFASs均具有生物累积性,且倾向于富集链长较短、带有羧酸基团或支链的PFASs组分,但对含醚键的新型PFASs 组分富集潜力较低。缺乏凯氏带或富含蛋白的蔬菜表现出较高的PFASs生物富集性,土壤有机质可通过吸附降低PFASs生物有效性,进而减小作物吸收。结合PFASs分子结构、蔬菜生理特征以及土壤有机质含量,本研究首次建立了预测效果良好的PFASs作物污染预测模型。此外,研究发现作物烹饪加热可促进短链PFASs组分挥发,但也可导致PFASs前体物大量降解。因此,本研究基于氧化法将前体物降解潜力纳入人体暴露与健康风险中,更大程度地保护了作物食用者的健康安全。

我校资源与环境学院硕士研究生刘顺为该论文第一作者,刘朝阳副教授为通讯作者。资源与环境学院谭文峰教授、陈畅博士、英国生态与水文中心Andrew C. Johnson教授、兰卡斯特大学Andrew J. Sweetman教授等参与了研究工作。该研究主要得到了国家自然科学基金、湖北省自然科学基金和中央高校基本科研业务费专项资金项目的资助。

图片2

此外,刘朝阳副教授前期基于受体模型与多元分析,解析了产业结构复杂的工农交错区稻田土壤中传统和新型PFASs的来源种类及相对贡献,并阐明了水稻对不同分子结构PFASs的生物富集规律与潜在健康风险,刘朝阳副教授作为第一作者和通讯作者将相关成果于2022年以“Source apportionment and crop bioaccumulation of perfluoroalkyl acids and novel alternatives in an industrial-intensive region with fluorochemical production, China: health implications for human exposure”为题发表在国际学术期刊Journal of Hazardous Materials上。结合后续的果树对PFASs吸收富集规律及健康风险研究,土壤化学与环境团队将在典型农业种植系统(包括粮食、蔬菜、水果)新污染物的源解析、风险评估与管控治理方面形成系统性的研究成果。

审核人:谭文峰

【英文摘要】

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.

论文链接

https://www.sciencedirect.com/science/article/pii/S0160412023000685

https://www.sciencedirect.com/science/article/pii/S0304389421019877

 

责任编辑:徐行 刘鸽