Heavy metals in industrial wastewater, soil and vegetables in Lohta village, India

A field study was conducted at four major sites that were irrigated by either treated or untreated wastewater in the Lohta village of Varanasi, India, receiving the discharged water from DLW (Diesel Locomotive Works) sewage treatment plant. Samples of irrigation water, soil and the edible portion of various vegetables were collected monthly during the summer and winter seasons. Heavy metals present in wastewater used for irrigation, organic matter, electrical conductivity, pH and nitrate–nitrogen of soil were analysed. Various vegetables were sampled in Lohta village and screened for Cd, Cr, Cu and Zn by inductively coupled plasma emission spectrometry and inductively coupled plasma mass spectrometry. These local food products are the basis of human nutrition in this region and of great relevance to human health, especially in developing countries. The results revealed that members of Brassicaceae (e.g. turnips, cabbage and radish) can efficiently accumulate the heavy metals and, henceforth, assessment of health risk should be explored.