Laboratório de Bioquímica e Toxicologia em Caenorhabditis elegans, Programa de Pós-Graduação em Bioquímica, Universidade Federal do Pampa- UNIPAMPA, Campus Uruguaiana, BR 472 - Km 592 - Caixa Postal 118, Uruguaiana, RS, CEP 97500-970, Brazil.
Laboratório de Estudos Físico-químicos e Produtos Naturais, Universidade Federal do Pampa, Campus Uruguaiana, Uruguaiana, Brazil.
Environ Sci Pollut Res Int. 2021 May;28(17):21730-21741. doi: 10.1007/s11356-020-11986-4. Epub 2021 Jan 7.
Uruguay River is the most important river in western Rio Grande do Sul, separating Brazil from Argentina and Uruguay. However, its pollution is of great concern due to agricultural activities in the region and the extensive use of pesticides. In a long term, this practice leads to environmental pollution, especially to the aquatic system. The objective of this study was to analyze the physicochemical characteristics, metals and pesticides levels in water samples obtained before and after the planting and pesticides' application season from three sites: Uruguay River and two minor affluents, Mezomo Dam and Salso Stream. For biomonitoring, the free-living nematode Caenorhabditis elegans was used, which were exposed for 24 h. We did not find any significant alteration in physicochemical parameters. In the pre- and post-pesticides' samples we observed a residual presence of three pesticides (tebuconazole, imazethapyr, and clomazone) and metals which levels were above the recommended (As, Hg, Fe, and Mn). Exposure to both pre- and post-pesticides' samples impaired C. elegans reproduction and post-pesticides samples reduced worms' survival rate and lifespan. PCA analysis indicated that the presence of metals and pesticides are important variables that impacted C. elegans biological endpoints. Our data demonstrates that Uruguay River and two affluents are contaminated independent whether before or after pesticides' application season. In addition, it reinforces the usefulness of biological indicators, since simple physicochemical analyses are not sufficient to attest water quality and ecological safety.
乌拉圭河是南里奥格兰德州西部最重要的河流，它将巴西与阿根廷和乌拉圭分隔开来。然而，由于该地区的农业活动和大量使用农药，其污染令人担忧。从长远来看，这种做法会导致环境污染，特别是对水系统造成污染。本研究的目的是分析三个地点（乌拉圭河以及两个较小的支流 Mezomo 大坝和 Salso 溪流）在种植和施药季节前后采集的水样的理化特性、金属和农药水平。为了进行生物监测，使用了自由生活的线虫秀丽隐杆线虫，将其暴露 24 小时。我们没有发现任何理化参数的显著变化。在施药前和施药后样本中，我们观察到三种农药（戊唑醇、咪唑乙烟酸和异恶草松）和金属残留，其水平高于建议值（砷、汞、铁和锰）。暴露于施药前和施药后样本均会损害秀丽隐杆线虫的繁殖能力，而施药后样本则降低了线虫的存活率和寿命。PCA 分析表明，金属和农药的存在是影响秀丽隐杆线虫生物学终点的重要变量。我们的数据表明，乌拉圭河和两条支流无论在施药季节前后都受到了污染。此外，它还强调了生物指标的有用性，因为简单的理化分析不足以证明水质和生态安全性。
