Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal.
Water Institute of the Northern Region, Rua Dr. Eduardo Torres 229, 4450-113 Matosinhos, Portugal.
Ecotoxicol Environ Saf. 2018 Apr 15;150:224-231. doi: 10.1016/j.ecoenv.2017.12.047. Epub 2018 Jan 4.
The present study aims to contribute to a better assessment of pesticide environmental and human health (here evaluated in the context of human exposure via food items) risks for the estuarine system by comprehensively studying the spatial and temporal occurrence of the pesticides atrazine, azoxystrobin, bentazon, λ-cyhalothrin, penoxsulam and terbuthylazine in the River Mondego estuary (Portugal). Pesticide quantification was performed in surface water, sediment, macroalgae (Ulva spp., Gracilaria gracilis, Fucus vesiculosus), aquatic plants (Zostera noltii, Spartina maritime, Scirpus maritimus) and bivalves (Scrobicularia plana). Since intense precipitation could promote the runoff of pesticides from the surrounding agricultural fields, a single long-duration flood event was also studied in this estuarine system. Under normal flow conditions, quantified concentrations were determined mostly during summer in agreement with the pesticide application period. Azoxystrobin presented the highest detection frequency and atrazine (an herbicide used globally but banned in the EU) presented the second highest frequency, thus highlighting the need to include legacy pesticides in monitoring programmes. Pesticide concentrations in surface water determined in the present study suggest low risk to estuarine organisms. However, all the pesticides were bioaccumulated by S. plana, leading us to consider that pesticides may not only cause adverse effects on the aquatic organism itself, but should also be an alert for human exposure, for this is an edible species and is considered of economic interest. Concern is also expressed about edible seaweeds, since s-triazine pesticides were found in Ulva spp. and G. gracilis. Acknowledging these concerns, developing and establishing allowable pesticide safety values for edible seaweeds and bivalves is recommended, as well as monitoring bivalve pesticide levels, using the whole animal, as a human health exposure indicator for estuarine systems. During the studied flood event, it appears that no serious pesticide contamination has occurred in the River Mondego estuary.
本研究旨在通过全面研究农药莠去津、唑菌胺酯、苯达松、高效氯氟氰菊酯、吡氟草肟和特丁津在蒙德古河口（葡萄牙）的时空分布，为评估河口系统中的农药环境和人类健康（此处评估的是通过食物摄入的人类暴露情况）风险提供帮助。在地表水、沉积物、大型藻类（Ulvaceae 属、石莼属、泡叶藻属）、水生植物（海菖蒲、互花米草、米草属）和双壳类动物（扁蜉螺属）中进行了农药定量分析。由于强降水可能会促进周围农田中的农药径流，因此本研究还对河口系统中的单次长时间洪水事件进行了研究。在正常流量条件下，与农药施用期一致，夏季的检测频率最高。唑菌胺酯的检出频率最高，其次是莠去津（一种在全球范围内使用但在欧盟被禁用的除草剂），这突出表明需要将传统农药纳入监测计划。本研究中测定的地表水农药浓度表明对河口生物的风险较低。然而，所有农药都被扁蜉螺属生物累积，这表明农药不仅可能对水生生物本身造成不利影响，还应引起对人类暴露的关注，因为这是一种可食用物种，被认为具有经济利益。人们还对食用海藻表示关注，因为在 Ulvaceae 属和石莼属中发现了三嗪类农药。鉴于这些担忧，建议为食用海藻和双壳类动物制定和建立可接受的农药安全值，并监测双壳类动物的农药水平，使用整个动物作为河口系统中人类暴露的指示物。在研究的洪水事件中，蒙德古河口似乎没有发生严重的农药污染。
