Effect of wastewater irrigation on soil and some selected vegetables grown in Asansol, West Bengal

This study was conducted in sub-urban region of Asansol, where wastewater from that Nunia nala is widely being used by poor farmers for irrigating vegetable on long-term basis. As a result elevated levels of heavy metals were found to accumulate in wastewater irrigated soil and vegetables, compared to well water irrigated soil and vegetables. The mean value of Pb, Mn and Zn content in both irrigation water showed the lower value in comparison to FAO/WHO standards, Cr and Cu value in wastewater and Cd value in both type of water exceeded the FAO/WHO standards. The trend of mean metal concentrations in well water and wastewater were Pb > Zn > Mn > Cr > Cd > Cu and Pb > Mn > Zn > Cr > Cd > Cu respectively. Pollution load index (PLI) level in soils were in the order of Cu (2.40) > Cr (2.19) > Cd (2.00) > Mn (1.77) > Pb (1.25) > Zn (0.97). Higher enrichment factor of Cd was found in spinach, Cu in brinjal, Mn in cauliflower and Mn and Zn in carrot and pea respectively.