Investigation of Drinking Water Quality and Residual Concentrations of Chlorpyrifos and Parathion Pesticides in Groundwater of Dezful city, Iran, in 2016

Agricultural development and lack of a proper strategy for the management of this domain can lead to the pollution of water and soil resources as a result of using various fertilizers and chemical pesticides. Contamination of underground water can be hazardous for human health, especially in areas where aquifers are used for home use (especially drinking). Regarding this, the present study was conducted to investigate the quality of drinking water based on the Iran Water Quality Index for Groundwater Resources-Conventional (IRWQIGC). This study was also targeted toward assessing the residual concentrations of chlorpyrifos and parathion pesticides in underground water in Dezful city, Iran, in 2016.

This study was conducted on 40 underground water samples (i.e., 24 samples for pesticides and 16 samples for water quality index) collected from 8 stations in Dezful city during the autumn and winter of 2016. After the extraction and preparation of specimens, the levels of chlorpyrifos and parathion residues were determined using the gas chromatography-electron capture detector.Furthermore, the measurement and classification of underground water quality were performed based on the IRWQIGCindex.

Based on the results, the water collected from Shams Abad Station had the highest level of chlorpyrifos in March (0.22μg/L). In addition, the level of parathion was lower than the limit of detection in all samples. Based on the IRWQIGC, the Mohajerin, Safi Abad, and Montazeri wells had the highest quality of drinking water, with the values of 75.11, 74.85, and 72.55, representing good quality. On the other hand, Kahnak well was found to have the lowest water quality with a value of 58.55 signifying a fairly good quality.

As the results indicated, underground water in Dezful city was of good quality, and the pesticide concentrations were lower than the standard limit of Iran. However, based on the standards of the World Health Organization and Environmental Protection Agency, the growing use of chlorpyrifos may pose some problems in the future