Water quality index and human health risk analysis in urban drinking water sources.

The present study was conducted to assess the quality of drinking water in urban areas of Hafizabad and Pindi Bhattian through the Water Quality Index (WQI) and Human Health Risk Assessment (HHRA). Forty-eight samples were collected from four sources of drinking water, including filter plants, tube wells, tap water, and bore wells. Water samples were analyzed for physical, chemical, and biological parameters. Results for all the parameters were compared with World Health Organization (WHO) guidelines. Results showed that temperature, turbidity, and electrical conductivity frequently exceeded WHO guidelines, while pH was within its allowable range. The chemical parameters, such as dissolved oxygen, total dissolved solids, total hardness, and calcium hardness met WHO guidelines. However, E. coli was found higher than both WHO guidelines and National Environmental Quality Standards (NEQS) in tap water samples. Arsenic concentration was also higher than standards in tap water of Hafizabad. According to WQI, several urban sources, particularly tap water, had a very poor or unfit class for drinking purposes. HHRA found arsenic to have both non-carcinogenic and carcinogenic risks for adults and children. These findings highlight the need for improved treatment, distribution-system integrity, and routine monitoring to reduce long-term health risks in urban and peri-urban settings.