DSI/NRF Research Chair, Shallow Water Ecosystems, Nelson Mandela University, PO Box 77000, Gqeberha, 6031, South Africa; Department of Botany, Institute of Coastal and Marine Research (CMR), Nelson Mandela University, PO Box 77000, Gqeberha, 6031, South Africa; Department of Chemistry, Nelson Mandela University, PO Box 77000, Gqeberha, 6031, South Africa.
Department of Chemistry, Nelson Mandela University, PO Box 77000, Gqeberha, 6031, South Africa.
Environ Pollut. 2022 Aug 1;306:119446. doi: 10.1016/j.envpol.2022.119446. Epub 2022 May 9.
The seasonal variation, spatial distribution, and ecological risks of thirteen organophosphate pesticides (OPPs) were studied in the Sundays and Swartkops estuaries in South Africa. Ten pesticides were detected in surface water samples from both estuaries, while all OPPs were detected in sediments. The highest concentration of OPPs (18.8 μg pyrazophos L) was detected in surface water samples from Swartkops Estuary, while 48.7 μg phosalone kg dw was the highest in sediments collected from Sundays Estuary. There was no clear seasonal pattern in OPPs occurrence in surface water from both systems. However, their occurrence in sediments was in the following order: winter > autumn > summer > spring, perhaps indicating major pesticide input in the winter seasons. Results from ecological risk assessment showed that pyraclofos and chlorpyrifos (CHL) in surface water from both systems are respectively likely to cause high acute and chronic toxicity to fish (risk quotient - RQ > 1). For sediments of both estuaries, the highest acute and chronic RQs for fish were calculated for isazophos and CHL respectively. The majority of the detected OPPs in sediments posed potential high risks to Daphnia magna from both systems. These results suggest that these aquatic organisms (fish, and Daphnia), if present in the studied estuaries, can develop certain forms of abnormalities due to OPP exposure. To this end, proper measures should be taken to reduce OPP input into the estuarine systems.
本研究调查了南非桑兹和斯瓦特克科普斯河口十三种有机磷农药（OPPs）的季节性变化、空间分布和生态风险。在两个河口的地表水样本中检测到十种农药，而所有 OPPs 都在沉积物中被检测到。在斯瓦特克科普斯河口的地表水样本中检测到最高浓度的 OPPs（18.8μg 吡唑磷 L），而在桑兹河口采集的沉积物中，最高浓度的 OPPs 是 48.7μg 硫丹 kg 干重。在两个系统的地表水样本中，OPPs 的出现没有明显的季节性模式。然而，它们在沉积物中的出现顺序为：冬季>秋季>夏季>春季，这可能表明冬季有大量农药输入。生态风险评估结果表明，两个系统的地表水样本中的吡虫啉和毒死蜱（CHL）分别可能对鱼类产生高急性和慢性毒性（风险商数-RQ>1）。对于两个河口的沉积物，计算出的最急性和慢性鱼类 RQ 分别为异稻瘟净和 CHL。在沉积物中检测到的大多数 OPPs 对两个系统的大型溞均构成潜在的高风险。这些结果表明，如果这些水生生物（鱼类和大型溞）存在于研究中的河口，它们可能会因 OPP 暴露而产生某些形式的异常。为此，应采取适当措施减少 OPP 输入到河口系统中。
