Health risk assessment of heavy metals via dietary intake of foodstuffs
from the wastewater irrigated site of a dry tropical area of India
The present study was conducted to assess the risk to human health by heavy metals (Cd, Cu, Pb, Zn, Ni
and Cr) through the intake of locally grown vegetables, cereal crops and milk from wastewater irrigated
site. Milk is not directly contaminated due to wastewater irrigation, but is an important route of food
chain transfer of heavy metals from grass to animals. Heavy metal concentrations were several fold
higher in all the collected samples from wastewater irrigated site compared to clean water irrigated ones.
Cd, Pb and Ni concentrations were above the ‘safe’ limits of Indian and WHO/FAO standards in all the vegetables
and cereals, but within the permissible limits in milk samples. The higher values of metal pollution
index and health risk index indicated heavy metal contamination in the wastewater irrigated site
that presented a significant threat of negative impact on human health. Rice and wheat grains contained
less heavy metals as compared to the vegetables, but health risk was greater due to higher contribution of
cereals in the diet. The study suggests that wastewater irrigation led to accumulation of heavy metals in
food stuff causing potential health risks to consumers.