Groundwater quality assessment and human health risks in Gujranwala District, Pakistan

The availability of safe drinking water is imperative for healthy life but access to safe drinking water has become a major problem around the world, especially in developing countries such as Pakistan. The present study aimed to: assess the suitability of groundwater for potable use in Gujranwala district, Pakistan; examine the spatial distribution patterns of water quality parameters; and to identify the prevalence of waterborne diseases among locals and health risks to humans due to the consumption of groundwater. Eighty drinking water samples were collected from different areas of Gujranwala and analyzed following Standard American Public Health Association methods. A questionnaire survey related to the incidence of waterborne diseases in the area was also carried out. The averaged water quality index (AWQI) was computed using ArcGIS 10.3 model builder. The AWQI map indicated that the water quality was generally suitable for potable use with regard to its physiochemical parameters. However, 97.5% water samples were found to be bacteriologically contaminated. The mean concentration of metals in drinking water showed a decreasing trend in the order Cr > Cu > Zn > As > Co > Ni > Cd. Health risk index (HRI) was also calculated for exposure to metal concentration. For Cd, one sample showed an HRI value > 1 i.e. 1.59 and 1.36 for child and adult, respectively, while HRI for As showed values > 1 varying between 0.5 and 11 for child, and 0.4 and 9.6 for adults. For other metals HRIs was less than 1 (considered to be safe for the consumers). The study concludes that groundwater quality of study areas of Gujranwala has mostly deteriorated.