Raw food items sold in most city markets have Lead concentration far above the permissible limit and can permanently damage key human organs, a survey conducted by the Geological Survey of India has found.
Samples of raw food items like polished rice, red lentil ,red spinach, chicken, fish, biscuits, spice and a common medicinal herb , collected from 12 markets in the city showed a mean Lead concentration between 3.78 and 43.35 mg/kg.
“The mean Lead concentration found in the raw food materials is very high compared to the threshold value of 2.5mg/kg specified by Food Safety & Standards Regulation (2011), India,” senior scientist of the GSI, Avijit Das, who headed the group conducting the two-year study, said Sunday.
As per the American and European standards, the current reference range for acceptable blood Lead-concentration in a healthy human being, without excessive exposure to environmental sources of Lead, is less than 0.05 mg/L for children whereas it is less than 0.25 mg/L for adults.
Prolonged exposure of lead, which is a highly toxic element, to humans can cause permanent damage to the kidneys, liver and hematologic systems.
Children are more at risk because lead exposure can reverse their brain growth and cause irreversible damage to their overall well being.
The study, conducted by leading scientists of the GSI, also found that about 75 per cent of the Lead contamination in the food items sold in Kolkata markets, were contributed by atmospheric Lead, mainly produced by the combustion of diesel.
Apart from collecting soil and vegetable samples from Dhapa ground, alongside the EM Bypass, for the study of Lead contamination, the scientists had also collected street dust samples from major roads of the northern and southern parts of the city for the study.
“Coal samples were collected from Jharia and Ranigunj to assess the presence of atmospheric lead from the use of coal while Galena (ore of Lead) samples from Alwar (Rajasthan) were brought to calculate the Lead Isotopic Ratio (LIR) of Indian lead,” Das said adding, rain water and diesel samples were collected from city markets for the study.