Human health risk assessment of heavy metals via dietary intake of vegetables grown in wastewater irrigated area of Rewa, India

In India, farmers are blindly using untreated industrial waste water for crops and vegetable production especially in peri-urban areas. Nowadays, increasing attention has focused on heavy metal concentrations of vegetables all over the world. Heavy metals have positive and negative roles in human life. Intake of vegetables is an important path of heavy metal toxicity to human being. The use of industrial waste water for irrigation exposes humans at various health risks. This is because heavy metals are not easily biodegradable and consequently can be accumulated in human vital organs. This situation cause varying degree of illness based on acute and chronic exposures. The present study was conducted to assess the risk to human health by heavy metals (Fe, Zn, Cu, Pb, Cd, Mn and Cr) through the intake of locally grown vegetables in Rewa city (M.P.) India, where, soils contaminated with heavy metals were mainly due to waste water irrigation from Cement Plants (Bela and Naubasta) and may be possible atmospheric deposition. The higher standard deviation reveals higher variation as in the heavy metal distributions from the point source of emission to the adjacent areas. In present study a value of intake of heavy metals in human diet was calculated to estimate the risk to human health. From the results the hazardous quotient (HQ) of all studied heavy metals indicated that all vegetables were safe with no risk to human health except for Pb (>1.0 to near 1.0) contamination in Spinach, Cauliflower and Radish had potential for human health risk due to consumption of these vegetables grown in the area having long term uses of untreated waste water for irrigation. Children are at somewhat higher risk than adults. However, DIR (<1.0) & HI (within1.0 to near 5.0) for all studied vegetables was found to be safe i.e. free of risks, it is therefore indicated that there is a relative absence of health risks associated with the ingestion of contaminated vegetables.