IMDEA Water Institute, Science and Technology Campus of the University of Alcalá, Av. Punto Com 2, Alcalá de Henares, 28805, Madrid, Spain; Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, c/ Catedrático José Beltrán 2, 46980, Paterna, Valencia, Spain.
University of Campinas, School of Technology, Rua Paschoal Marmo 1888 - Jd., Nova Itália, Limeira, 13484-332, Brazil.
Chemosphere. 2022 Mar;291(Pt 1):132821. doi: 10.1016/j.chemosphere.2021.132821. Epub 2021 Nov 7.
The use of pesticides in households and peri-urban areas of the Amazon has increased notably during the last years. Yet, the presence of these contaminants in Amazonian freshwater ecosystems remains unexplored. Here, we assessed the exposure to 18 pesticides and 5 transformation products in the Amazon River and in the urban streams of Manaus, Santarém, Macapá, and Belém (Brazil). Pesticide concentrations were analyzed by liquid and gas chromatography methods. Ecological risks were assessed following a two-tiered approach. First, hazard quotients and an overall hazard index were calculated using toxicity data for standard test species of primary producers, invertebrates, and fish. Second, the pesticides showing moderate-to-high ecological risks in the first tier were evaluated using Species Sensitivity Distributions (SSDs). Our study shows that pesticides are widespread in urban and peri-urban areas of the Brazilian Amazon. The frequency of detection was higher in urban streams than in the Amazon River, with some samples taken in Manaus, Santarém, and Belém containing up to 8 compounds. Most pesticides were measured at relatively low concentrations (ng L), except for malathion, carbendazim and the bulk concentration of chlorpyrifos, which were monitored at concentrations above 100 ng L. Based on the first-tier assessment, we found moderate-to-high risks for freshwater invertebrates for malathion, chlorpyrifos, and chlorpyrifos-methyl, and moderate risks for malathion to fish. The risk assessment performed with SSDs indicated high risks of malathion and chlorpyrifos-methyl in urban areas, with up to 15% and 5% of invertebrate species potentially affected, respectively. The bulk concentrations of chlorpyrifos resulted in high risks in some urban areas (14-22% of species affected) and in areas of the main river (32-44%) impacted by agriculture. We conclude that pesticide residues may contribute to a biodiversity impact in the Amazon and should be further monitored in urban and peri-urban areas, particularly after heavy rainfall events.
近年来，家用和城市周边地区在亚马逊地区使用农药的情况显著增加。然而，这些污染物在亚马逊淡水生态系统中的存在仍然没有得到探索。在这里，我们评估了亚马逊河和马瑙斯、圣塔伦、马卡帕和贝伦（巴西）城市溪流中 18 种农药和 5 种转化产物的暴露情况。采用液相和气相色谱法分析农药浓度。采用两级方法评估生态风险。首先，使用原生生物、无脊椎动物和鱼类的标准测试物种的毒性数据计算危害系数和总体危害指数。其次，使用物种敏感性分布（SSD）评估在第一级中表现出中至高生态风险的农药。我们的研究表明，农药在巴西亚马逊地区的城市和城市周边地区广泛存在。在城市溪流中的检出频率高于亚马逊河，在马瑙斯、圣塔伦和贝伦采集的一些样本中含有多达 8 种化合物。除马拉硫磷、多菌灵和毒死蜱的大量浓度外，大多数农药的浓度都相对较低（ng/L），在马瑙斯、圣塔伦和贝伦监测到的马拉硫磷、毒死蜱和毒死蜱 - 甲基的浓度超过 100ng/L。根据第一级评估，我们发现马拉硫磷、毒死蜱和毒死蜱 - 甲基对淡水无脊椎动物有中至高风险，马拉硫磷对鱼类有中度风险。使用 SSD 进行的风险评估表明，马拉硫磷和毒死蜱 - 甲基在城市地区风险很高，分别有多达 15%和 5%的无脊椎动物物种可能受到影响。在一些城市地区（受影响的物种占 14-22%）和受农业影响的主要河流地区（受影响的物种占 32-44%），毒死蜱的大量浓度导致高风险。我们得出结论，农药残留可能对亚马逊的生物多样性产生影响，应在城市和城市周边地区进一步监测，特别是在暴雨事件后。
