Drinking water quality and human health risk in Charsadda district, Pakistan

Access to safe drinking water is one of the basic human rights and essential for healthy life. The present study investigated the concentrations of various pollutants in drinking water and health risk in Charsadda district, Khyber Pakhtunkhwa, Pakistan. Water samples were collected from dug-wells, tube-wells and hand pumps which were the most common sources of drinking water and analyzed for physical parameters, anions, heavy metals and coliform bacteria using standard methods. The concentrations of nitrate (10.3-14.84 mg L−1) in 13 sites exceeded the permissible limit (10 mg L−1) set by US-EPA, while sulfate concentrations (505-555 mg L−1) in 9 sites exceeded the permissible limit (500 mg L−1) set by WHO. Similarly, the concentrations of Pb, Cd, Ni and Fe exceeded their respective permissible limits set by different organizations in some locations. Furthermore, the coliform bacterial contamination (2-5 MPN 100 mL−1) was also found in some sources of water, confirming the bacterial contamination of drinking water. In the study area, improper disposal of sewage and solid wastes, over application of agrochemicals (pesticides and fertilizers), deteriorating condition of piping network and transportation were the major sources responsible for contamination of drinking water. Water contamination with coliform bacteria was the main source of waterborne diseases like gastroenteritis, dysentery, diarrhea and viral hepatitis as complained by most of the respondents during questionnaire survey. In order to reduce the health risk, it is necessary to immediately stop the uses of drinking water from contaminated sources and government should supply treated/clean water with supply lines far away from solid waste, sludge and sewage sites. The farmers should be properly trained to avoid the overusing of agrochemicals responsible for drinking water contamination, while both women and men should be properly educated with water knowledge through awareness and training programs needed for sustainable use and management of drinking water.