School of Environmental Health, College of Health and Medical Sciences, Haramaya University, 235 Harar, Ethiopia; Department of Biology, College of Computational and Natural Science, Hawassa University, 05 Hawassa, Ethiopia.
Department of Biology, College of Computational and Natural Science, Hawassa University, 05 Hawassa, Ethiopia.
Sci Total Environ. 2024 Feb 10;911:168727. doi: 10.1016/j.scitotenv.2023.168727. Epub 2023 Nov 23.
In most developing countries, including Ethiopia, a conspicuous gap exists in understanding risk of pesticides and establishing robust regulatory frameworks for their effective management. In this context, we present a detailed assessment of pesticide risks within Ethiopian aquatic ecosystems in at least 18 distinct surface water bodies, including 46 unique sample locations. Measured environmental concentrations (MECs; n = 388) of current-use pesticides (n = 52), sourced from existing field studies, were compared against their respective regulatory threshold levels (RTLs). The results indicated a scarcity of pesticide exposure data across the majority of Ethiopian water bodies situated within agricultural watersheds. Importantly, surface water pesticide concentrations ranged from 0.0001 to 142.66 μg/L, with a median concentration of 0.415 μg/L. The available dataset revealed that 142 out of 356 MECs (approximately 40 %) of the identified pesticides entail significant acute risks to aquatic ecosystems, with the highest RTL exceedances up to a factor of 8695. Among the pesticide use groups, insecticides exhibited the highest exceedance rate, while this was rarer for fungicides and herbicides. Furthermore, a species-specific insecticide risk assessment indicated aquatic invertebrates (54.4 %) and fishes (38.4 %) are more exposed to pesticide risks, attributable to pyrethroids and organophosphates. In conclusion, our findings demonstrate that the presently registered pesticides in Ethiopia carry elevated risks towards aquatic environments under real-world settings. This challenges the notion that pesticides approved through Ethiopian pesticide regulatory risk assessment entail minimal environmental hazards. Consequently, we advocate for the adoption of more refined risk assessment strategies, a post-registration reevaluation process, and, if deemed necessary, the imposition of bans or restrictions on highly toxic pesticides.
在大多数发展中国家，包括埃塞俄比亚，人们对农药风险的认识存在明显差距，并且难以建立健全的监管框架来对其进行有效管理。在此背景下，我们对埃塞俄比亚至少 18 个不同地表水体内的水生生态系统中的农药风险进行了详细评估，其中包括 46 个独特的采样点。我们比较了从现有实地研究中获取的当前使用的农药（52 种）的实测环境浓度（MEC；n=388）与各自的监管阈值水平（RTL）。结果表明，在位于农业流域内的大多数埃塞俄比亚水体中，农药暴露数据严重缺乏。重要的是，地表水中的农药浓度范围为 0.0001 至 142.66μg/L，中位数浓度为 0.415μg/L。现有数据集显示，在所识别的农药中，有 356 个 MEC 中的 142 个（约 40%）对水生生态系统具有显著的急性风险，最高 RTL 超标高达 8695 倍。在所使用的农药类别中，杀虫剂的超标率最高，而杀菌剂和除草剂则较少超标。此外，对特定物种的杀虫剂风险评估表明，水生无脊椎动物（54.4%）和鱼类（38.4%）更容易受到杀虫剂的风险影响，这归因于拟除虫菊酯和有机磷化合物。总之，我们的研究结果表明，埃塞俄比亚目前注册的农药在现实环境下对水生环境存在较高风险。这一结果挑战了通过埃塞俄比亚农药监管风险评估批准的农药对环境危害最小的观点。因此，我们主张采取更精细的风险评估策略、登记后重新评估程序，并且在必要时对高毒性农药实施禁令或限制。
