Laboratory of Environmental Toxicology and Aquatic Ecology, Department of Animal Sciences and Aquatic Ecology, Ghent University, Coupure Links 653, block F, 9000 Ghent, Belgium.
Laboratory of Environmental Toxicology and Aquatic Ecology, Department of Animal Sciences and Aquatic Ecology, Ghent University, Coupure Links 653, block F, 9000 Ghent, Belgium.
Sci Total Environ. 2019 Jan 1;646:996-1008. doi: 10.1016/j.scitotenv.2018.07.185. Epub 2018 Jul 30.
The rapid increase and transition to more intensive agricultural activities in developing nations are often leading to misuse and overuse of pesticides, making their environment vulnerable for pesticide accumulation. In the present study, the Guayas river basin was taken as a representative case study to evaluate pesticide contamination of the Ecuadorean freshwater environment. Pesticide contamination was determined at 181 sampling sites by a multi-residue method using solid phase extraction (SPE) and pesticide residues were linked with agricultural land use activities to identify the main pollution sources. Moreover, the biological water quality status based on macroinvertebrate communities was determined at every location and the relation with the occurrence of pesticide residues was further investigated. Results showed that pesticide contamination of the freshwater environment was widely present in the Guayas river basin with detections at 108 sampling sites (60%). A total of 26 pesticide products were identified. Most frequently detected pesticides included cadusafos (62 locations), butachlor (21 locations) and pendimethalin (21 locations), with concentrations up to 0.081, 2.006 and 0.557 μg·L respectively. Pesticide residues detected in this study did not significantly influence the biological water quality (p = 0.69), but were observed to be positively correlated with ammonium concentrations, supporting the assumed combined application of chemical fertilizers and pesticides in agriculture. These pesticide residues were also associated with one or more agricultural crops, with in particular the banana and rice industries identified as major pollution sources. Both high consumption rates and non-specific application methods, such as aerial spraying of banana plantations and application directly into the water layer of irrigated rice fields, may attribute to pesticide contamination of the freshwater environment of the Guayas river basin. It is therefore suggested that measures, e.g. legal regulations and awareness campaigns, taken to prevent environmental pollution and accumulation of pesticides primarily focus on these industries.
发展中国家农业活动的快速增长和转型往往导致农药的滥用和过度使用，使环境容易受到农药积累的影响。在本研究中，瓜亚斯河流域被选为代表案例，以评估厄瓜多尔淡水环境中的农药污染。通过固相萃取 (SPE) 多残留方法，在 181 个采样点确定了农药污染情况，并将农药残留与农业土地利用活动联系起来，以确定主要污染源。此外，还在每个地点确定了基于大型底栖无脊椎动物群落的水质生物状况，并进一步调查了与农药残留发生的关系。结果表明，瓜亚斯河流域的淡水环境广泛存在农药污染，在 108 个采样点（60%）检测到农药残留。共鉴定出 26 种农药产品。最常检测到的农药包括毒死蜱（62 个地点）、丁草胺（21 个地点）和扑草净（21 个地点），浓度高达 0.081、2.006 和 0.557μg·L。本研究中检测到的农药残留并没有显著影响水质生物（p=0.69），但与铵浓度呈正相关，支持农业中化肥和农药的联合应用。这些农药残留也与一种或多种农作物有关，特别是香蕉和水稻产业被确定为主要污染源。香蕉种植园的高空喷洒和直接施入灌溉稻田水层等高消耗率和非特异性应用方法可能导致瓜亚斯河流域淡水环境的农药污染。因此，建议采取措施，例如法律规定和宣传活动，主要针对这些行业，以防止环境污染和农药积累。
