Appraisal of heavy metal contents in groundwater and associated health hazards posed to human population of Ropar wetland, Punjab, India and its environs.

Abstract

Heavy metals are well recognised for their toxicity and pose human health risks even at very low levels. In the present work, groundwater from Ropar wetland, Punjab, India and its environs (18 sites), were analysed for physico-chemical parameters, water quality indices, heavy metal contents (cadmium, cobalt, chromium, copper, lead and zinc) and possible health risks posed to adults and children during summer and winter seasons. Groundwater was slightly-alkaline, non-saline and hard which may be suitable for irrigation purposes. Among 18 samples, 7 and 9 samples in summer; 8 and 18 samples in winter exceeded BIS acceptable limits (mg L-1) of 0.003 and 0.05 for cadmium and chromium, respectively. Mean non-cancer hazard quotients for cobalt (5.09-7.63) were >1. Mean hazard indices for cumulative risks posed by all heavy metals (6.00-10.11) were also >1. These results indicated higher risk of non-cancerous health problems in residents of the study area. Chromium was found to pose significant possible cancer risk (1.20-2.99 cases/1000 persons). Children were more prone to health problems than adults due to their lower body weight with greater risk in winters, which may be attributed to higher contamination of heavy metals in groundwater after leaching during monsoons. The results of water quality analysis and risk assessment indicated that the groundwater suffered from significant contamination and if used for long-term without pre-treatment, may pose serious health risks to human population via drinking water and irrigation of agricultural fields due to bioconcentration of heavy metals in food crops cultivated in those fields.