Analysis of the Ecological Toxicity of Pesticides, Heavy Metals and Microbial Pollution and their combined effects, in the Running Surface Water of Jhal Magsi, Pakistan

Monitoring water quality is highly important for ensuring clean drinking water and protection of aquatic environments. The aim of the current study was to estimate the quality of running water sources from the district of Jhal Magsi. This study focused on evaluating the effects of low biodegradability, the accumulation of heavy metals and organics, and the presence of these compounds on water quality. The concentrations of herbicides (DDT (2,4 D) and Cyanazine) and insecticides (chlorpyrifos, Aldrin and Dieldrin) were determined via gas chromatography, and the concentrations of heavy metals (Pb and Cd) and trace elements (Zn and Mn) were detected via an atomic absorption spectrophotometer. Identification of E. coli and P. aeruginosa was performed by Gram staining and biochemical tests. DDT (2,4 D), Cyanazine, Chlorpyrifos, and Aldrin & Dieldrin were detected at 0.9 ± 0.058, 0.08 ± 0.006, 1.01 ± 0.577 and 1.1 ± 0.577 mg/L, respectively; these values are higher than the WHO safety limits. The heavy metals Pb and Cd were detected in all the samples, and the highest range for Pb was 2.03 ± 0.577 mg/L, while that for Cd was 0.48 ± 0.058 mg/L. The highest concentrations of the trace elements Zn and Mn were detected, and the WHO recommended safe limits were 0.305 ± 0.058 and 0.99 ± 0.058 mg/L, respectively. E. coli and P. aeruginosa were identified with percentages of 51.51 and 48.48%, respectively. The presence of higher concentrations of pesticides and heavy metals and their synergistic effect indicate a risk for both human health and aquatic organisms. Therefore, continuous monitoring of heavy metals and pesticides is necessary in the water reservoirs of Jhal Magsi to ensure drink safety. Bacterial assessment can aid in accepting bioremediation processes in water.