State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Environ Int. 2017 Sep;106:37-47. doi: 10.1016/j.envint.2017.05.014. Epub 2017 May 27.
Significant quantities of perfluoroalkyl acids (PFAAs) are released to the environment from fluorochemical manufacturing processes through wastewater discharge and air emission in China, which may lead to human exposure and health risks through crop bioaccumulation from PFAAs-contaminated soil and irrigation water. This paper systematically studied the distribution and transport of PFAAs in agricultural soil, irrigation water and precipitation, followed by crop bioaccumulation and finally human exposure of PFAAs within a 10km radius around a mega-fluorochemical industrial park (FIP). Hotspots of contamination by PFAAs were found near the FIP and downstream of the effluent discharge point with the maximum concentrations of 641ng/g in agricultural soil, 480ng/g in wheat grain, 58.8ng/g in maize grain and 4,862ng/L in precipitation. As the distance increased from the FIP, PFAAs concentrations in all media showed a sharp initial decrease followed by a moderate decline. Elevated PFAA concentrations in soil and grains were still present within a radius of 10 km of the FIP. The soil contamination was associated with the presence of PFAAs in irrigation water and precipitation, and perfluorooctanoic acid (PFOA) was the dominant PFAA component in soil. However, due to bioaccumulation preference, short-chain perfluoroalkyl carboxylic acids (PFCAs), especially perfluorobutanoic acid (PFBA), became the major PFAA contaminants in grains of wheat and maize. The bioaccumulation factors (BAFs) for both grains showed a decrease with increasing chain length of PFAAs (approximately 0.5 log decrease per CF group). Compared to maize grain, wheat grain showed higher BAFs, possibly related to its higher protein content. The PFCA (C4-C8) concentrations (on a log basis) in agricultural soil and grain were found to show a linear positive correlation. Local human exposure of PFOA via the consumption of contaminated grains represents a health risk for local residents, especially for toddlers and children.
在中国，大量全氟烷基酸（PFAAs）通过含氟化学品制造过程中的废水排放和空气排放释放到环境中，这可能导致人类通过受 PFAAs 污染的土壤和灌溉水中的农作物生物累积而接触和面临健康风险。本文系统地研究了 PFAAs 在农业土壤、灌溉水和降水中的分布和迁移，接着研究了农作物的生物累积，最后研究了在一个大型含氟化学品工业园（FIP）周围 10 公里半径范围内的 PFAAs 对人类的暴露。在 FIP 附近和废水排放点下游发现了 PFAAs 的污染热点，农田土壤中的最大浓度为 641ng/g，小麦籽粒中的浓度为 480ng/g，玉米籽粒中的浓度为 58.8ng/g，降水中的浓度为 4862ng/L。随着与 FIP 的距离增加，所有介质中的 PFAAs 浓度均急剧下降，随后适度下降。在 FIP 周围 10 公里范围内，土壤和谷物中的 PFAA 浓度仍然很高。土壤污染与灌溉水和降水中 PFAAs 的存在有关，全氟辛酸（PFOA）是土壤中主要的 PFAA 成分。然而，由于生物累积的偏好，短链全氟烷基羧酸（PFCAs），特别是全氟丁酸（PFBA），成为小麦和玉米籽粒中主要的 PFAA 污染物。两种谷物的生物累积因子（BAFs）随 PFAAs 链长的增加而降低（每个 CF 组约降低 0.5 个对数单位）。与玉米籽粒相比，小麦籽粒表现出更高的 BAFs，这可能与其较高的蛋白质含量有关。农业土壤和谷物中 PFCAs（C4-C8）浓度（以对数为基础）呈线性正相关。当地居民通过食用受污染的谷物摄入 PFOA 会对健康造成风险，尤其是对幼儿和儿童。
