IIIA-UNSAM-CONICET, Instituto de Investigación e Ingeniería Ambiental, Escuela de Hábitat y Sostenibilidad, San Martín, Buenos Aires, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
Water Environ Res. 2023 Jun;95(6):e10899. doi: 10.1002/wer.10899.
Amphibians are subject to several stressors in the aquatic and terrestrial environments, and human activities have profoundly impacted this vertebrate group. The aim of the present study was to analyze physicochemical parameters, metals and pesticide residues, and the toxicity of water and sediment samples from an environment with high agricultural activity (S1: Salto stream; S2: drainage channel downstream from S1) by means of bioassays using Rhinella arenarum (Amphibia: Anura) larvae. Metals and pesticides were analyzed in water and sediment samples by fluorescence spectrometer of X-ray by total reflection and ultra-high-performance liquid chromatography-MS/MS, respectively. For lethality bioassays, 10 larvae (in triplicate) were exposed for 504 h to water and sediment samples. Also, 50 larvae were exposed for 96 h (in triplicate) to water and sediment samples for the evaluation of biomarkers of neurotoxicity, oxidative stress, and genotoxicity. Twenty-six different pesticides (mainly herbicides) were detected in both sites, and Cu, Zn, and Pb exceeded the limit for protection of aquatic life. Lethality was observed in larvae exposed to water and sediment samples from both sites at chronic exposure. Oxidative stress was observed in larvae exposed to both sites. In larvae exposed to samples from S1, alterations in the neurotoxicity biomarkers were observed. These results alert about the degradation of the sites and highlight the need to monitor and control the use of pesticides. PRACTITIONER POINTS: Twenty-six pesticides were detected in water and sediment from Salto stream basin. Significant mortality was observed in larvae exposed to samples from all sites. Sublethal effects were observed mainly in larvae exposed to samples from Salto stream. The degraded quality can be associated with the agricultural activities of the area.
两栖动物在水生和陆地环境中受到多种胁迫，人类活动对这一类脊椎动物产生了深远的影响。本研究的目的是通过使用 Rhinella arenarum（两栖纲：无尾目）幼虫进行生物测定来分析具有高农业活动的环境（S1：萨尔托溪；S2：S1 下游的排水渠）中的水和沉积物样品的理化参数、金属和农药残留以及水和沉积物的毒性。采用 X 射线全反射荧光光谱仪和超高效液相色谱-MS/MS 分别对水样和底泥样品中的金属和农药进行分析。对于致死生物测定，将 10 只幼虫（一式三份）暴露于水样和底泥样品中 504 小时。还将 50 只幼虫（一式三份）暴露于水样和底泥样品中 96 小时，以评估神经毒性、氧化应激和遗传毒性的生物标志物。在两个地点都检测到了 26 种不同的农药（主要是除草剂），Cu、Zn 和 Pb 超过了保护水生生物的限量。在慢性暴露下，暴露于两个地点的水样和底泥样品中的幼虫都观察到了致死性。暴露于两个地点的幼虫都观察到了氧化应激。暴露于 S1 样品的幼虫观察到神经毒性生物标志物的改变。这些结果提醒人们注意到这些地点的退化，并强调需要监测和控制农药的使用。
