Human cancer risk due to chromium and its bioaccumulation in physids in Central Punjab, Pakistan.

The present study aims to assess the ecological risk of chromium [Cr(VI)] in the water and soil of Central Punjab and its natural bioremediation through physids. Members of the genus Physa are cosmopolitan as they are resistant to various pollutants. The snails of the genus Physa were sampled from October through March. Three species, i.e., P. acuta, P. fontinalis, and P. gyrina, were identified. The foot, shell, water, and soil samples were tested for the presence of the hexavalent chromium, using ICP-MS. The maximum mean concentration of chromium in soil was found in GB(R8), i.e., 2.66 ppb. The maximum mean concentration of chromium in water was found in RB(R4), 1.627 ppb. The highest maximum average daily dose (ADD) was found in RB:R6, with a hazard quotient (HQ) of 32.32 and a carcinogenic risk (CR) of approximately 20 in every 100 children as a result of water pollution which is quite similar to RB:R5 showing these are extremely polluted area due to chromium. The pollution level of chromium in soil of Faisalabad is less than zero and safe while water is unsuitable for drinking as the value of water quality index (WQI) is higher than 100. No significant difference among the three species was found regarding bioaccumulation of chromium, in the snail shell and body. Physids play an active role in the bioremediation of soil and water yet may become cancer-causing tablets in the food chains of the region.