Monitoring and spatiotemporal variations of pyrethroid insecticides in surface water, sediment, and fish of the river Chenab Pakistan

There is a serious concern regarding freshwater resources of Pakistan which have been mismanaged and now are depleting extensively due to other reasons like intensive application of agricultural pesticides and insecticides. The present study was conducted to determine the concentrations of cypermethrin, deltamethrin, permethrin, and bifenthrin in the samples of water, sediments, and fish collected from various locations of River Chenab, Pakistan, during summer and winter seasons. These locations include namely Marala, Khanki, Qadirabad, and Trimu Headworks. High-performance liquid chromatography (HPLC) was deployed for analysis and determination of pyrethroid concentrations in these samples. The analytics show the order of pyrethroid concentrations in river as fish> sediment>water. Whereas maximum concentrations of 0.472 μg g−1 found in fish and minimum concentrations were determined in water, i.e., 0.087 μg L−1 at the sampling locations of Trimu and Marala headworks, respectively. Moreover, highest mean concentrations of pyrethroid, i.e., 1.248 μg g−1 in fish were detected in winter season as compared to summers, i.e., 0.087 μg L−1. However, all the values of pyrethroid were found to be lower than the maximum permissible levels specified by EU and WHO-FAO. Whereas the levels of deltamethrin and permethrin in water were found much higher than the specific limits set by EU.