Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China; Danzhou Scientific Observing and Experimental Station of Agro-Environment, Ministry of Agriculture and Rural Affairs, Danzhou, 571737, China; National Agricultural Experimental Station for Agricultural Environment, Danzhou, 571737, China; Hainan Engineering Research Center for Non-point Source and Heavy Metal Pollution Control, Danzhou, 571737, China.
Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China; School of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
Environ Pollut. 2021 Aug 15;283:117100. doi: 10.1016/j.envpol.2021.117100. Epub 2021 Apr 12.
Pesticides are heavily applied in rice-vegetable rotations in tropical China, yet publicly available information on the contamination and risk of currently used pesticides (CUPs) and legacy pesticides (LPs) in surface waters of river basins draining these areas is very limited. Therefore, in two tropical river basins (Nandu River and Wanquan River basins) dominated by rice-vegetable rotations in Hainan, China, pesticides were analyzed in 256 surface water samples in wet and dry seasons. Forty-one pesticides were detected, and total concentrations ranged from not detectable to 24.2 μg/L. Carbendazim and imidacloprid were the two most prevalent CUPs, detected in 59.8% and 17.7%, respectively, of surface water samples at concentrations above 0.1 μg/L. Chlorpyrifos was the main LP, detected in 9.0% of samples at a concentration above 0.05 μg/L. The fungicides difenoconazole and emamectin benzoate, the herbicide butachlor, and the insecticide acetamiprid occurred in ≥12.5% samples at concentrations above 0.1 μg/L. Surface waters typically (85.2%) contained 5 to 15 residues, with an average of nine. Seasonally, the concentrations of the 41 pesticides were in the order January > July > November > September. Spatially, the composition of the main CUPs (not LPs) was significantly different depending on position in the drainage, which also changed with seasons. Crop and pest types and wet and dry seasons were the key factors controlling the spatiotemporal distribution of CUPs and LPs in surface waters. On the basis of evaluations of the exposures to individual pesticides and the dominant combinations with ≥8 pesticides, multiple pesticides were likely a significant risk to aquatic organisms, although noncarcinogenic and carcinogenic risks to humans were low. This study provides valuable data to better understand pesticide occurrence and ecological risks in river basins draining areas with rice-vegetable rotation systems in tropical China.
在中国热带地区，水稻-蔬菜轮作中大量使用农药，但目前关于这些地区流域地表水受污染情况和风险的公开信息非常有限。因此，在中国海南两个以水稻-蔬菜轮作为主的热带流域（南渡江和万泉河流域），我们在干湿两季采集了 256 个地表水样本，对其中的农药进行了分析。共检出 41 种农药，总浓度范围为未检出至 24.2μg/L。多菌灵和吡虫啉是两种最常见的 CUPs，分别在 59.8%和 17.7%的地表水样本中被检出，浓度均高于 0.1μg/L。毒死蜱是主要的 LP，在 9.0%的样本中被检出，浓度高于 0.05μg/L。杀菌剂噻菌灵和甲氨基阿维菌素苯甲酸盐、除草剂丁草胺和杀虫剂乙虫腈的浓度均高于 0.1μg/L，分别出现在 12.5%以上的样本中。地表水通常（85.2%）含有 5 到 15 种残留农药，平均 9 种。季节性方面，41 种农药的浓度顺序为 1 月>7 月>11 月>9 月。空间上，主要 CUPs（非 LP）的组成因排水位置不同而显著不同，这也随着季节而变化。作物和病虫害类型以及干湿季节是控制地表水 CUPs 和 LP 时空分布的关键因素。基于对个体农药暴露的评估和≥8 种农药的主要组合，多种农药可能对水生生物构成重大风险，尽管对人类的非致癌和致癌风险较低。本研究为更好地了解中国热带地区水稻-蔬菜轮作系统流域中农药的出现和生态风险提供了有价值的数据。
