Pesticide Contamination of Potable Water and Its Correlation with Water Quality in Different Regions of Punjab, Pakistan

The widespread use of pesticides leads to the contamination of groundwater, which harms environment and threatens life. The goal of the current study was to determine the degree of pesticide contamination of groundwater in agricultural regions with varying degrees of pesticide use. In 15 districts of the Punjab province of Pakistan, chemical residues of major pesticide groups including, neonicotinoids, organophosphates, carbamates and pyrethroids were detected in the water samples. Two most commonly used herbicides, isoproturan and diuron, were also tested but not detected in any of the water samples. Five districts in the southern Punjab/core area had highly contaminated groundwater due to the presence of residues from all major insecticide groups. Although less severe than in the core area, a different set of five districts in central Punjab also had significant water contamination issues. The districts located in marginal area had the lowest amount of insecticide residues. The highest levels of imidacloprid residues were identified in the core area throughout the winter season. Thiacloprid, fipronil, and acetamiprid were detected in nearly all water samples, with non-significant differences in concentrations throughout the summer and winter seasons, as well as in non-core and marginal areas. Different water quality parameters including, pH, electrical conductivity and temperature had varying degree of correlations with pesticide residues in water samples. Overall, it is concerning that significant insecticides are widely contaminating groundwater. This issue should be managed through integrated pest management, non-chemical pest control strategies, and judicious chemical use practices.