Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou, 310015, China.
Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou, 310015, China; College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015, China.
Environ Pollut. 2022 Aug 15;307:119567. doi: 10.1016/j.envpol.2022.119567. Epub 2022 May 31.
The contamination of paddy soils is of great concern since it links to human health via food supply. Limited knowledge is available on PCB residue characteristics and the associated health risks in paddy soils under various environmental conditions. In this study, a soil sampling campaign was conducted in three typical paddy fields, i.e., Sanjiang Plain (SP), Taihu Plain (TP) and Hani Terrace (HT), crossing a transect of 4000 km in China. The concentrations of 29 quantified PCBs varied from 58.6 to 1930 pg/g in paddy soils, with samples at TP showing the highest burden. Tri-CBs were the major homologue group at SP and HT, whereas hexa-CBs at TP. Altitude, temperature, soil organic matter content and soil conductivity well explained the variations in PCB concentrations among sites. The homologue profiles of soil PCBs followed the fractionation theory. In addition, soil conductivity was found to be negatively correlated to low-chlorinated PCBs and positively to high-chlorinated congeners. Furthermore, the toxicities of soil PCBs and the exposure risks through rice intake were estimated. Higher toxicity equivalent quantities and hazard indexes were found at SP than TP and HT, with over one third of the samples displaying health risks. The results of this work highlight the necessity to better understand the occurrence characteristics and the associated health risks of PCBs in soils of rice-growing regions.
稻田土壤的污染备受关注，因为它通过食物供应与人类健康息息相关。然而，对于不同环境条件下稻田中多氯联苯（PCBs）残留特征及相关健康风险的认识还很有限。本研究在中国进行了一次土壤采样活动，在三个典型的稻田（三江平原（SP）、太湖平原（TP）和哈尼梯田（HT））中进行了采样，跨越了 4000 公里的横断面。稻田土壤中 29 种定量 PCBs 的浓度范围为 58.6 至 1930 pg/g，TP 地区的样本含量最高。在 SP 和 HT 地区，三氯联苯是主要的同系物组，而在 TP 地区则是六氯联苯。海拔、温度、土壤有机质含量和土壤电导率很好地解释了不同地点之间 PCB 浓度的变化。土壤 PCBs 的同系物分布遵循分馏理论。此外，土壤电导率与低氯代 PCBs 呈负相关，与高氯代同系物呈正相关。此外，还评估了土壤 PCBs 的毒性和通过摄入大米所带来的暴露风险。SP 地区的毒性当量和危害指数高于 TP 和 HT，超过三分之一的样本显示存在健康风险。这项工作的结果强调了有必要更好地了解水稻种植区土壤中 PCBs 的发生特征及其相关的健康风险。
