GSI planning blood tests to study lead contamination

Geological Survey of India(GSI) is planning blood tests of the city's denizens after one of its studies revealed that raw food items sold in different markets of Kolkata have alarming levels of lead in them.
The blood tests will be conducted to estimate how many have been affected by the concentration of the heavy metal and to conduct a detailed study on the pattern of contamination in those who have been consuming the food items from these markets, a senior scientist from the GSI told PTI today.
"It's well known that people have lead in their blood but what we need to find out is the magnitude of its concentration. For that we are planning to collect blood samples from the people in the city to conduct the tests," he said.

The blood-collection process for the test is likely to be started from April next year, said the scientist, who is linked to the study that revealed the high level of lead content in raw food items sold in the city markets.
A recent study by GSI scientists said samples of raw food items like polished rice, red lentil (masoor dal), red spinach, chicken, fish (without scales), biscuits, spice (cumin seeds) and even tulsi, a common medicinal herb, collected from 12 markets in the city showed a mean lead concentration between 3.78 and 43.35 mg/kg (average 23.56 mg/kg).
The study 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.

As per the American and European standards, the current reference range for acceptable blood lead concentration in a healthy adult who does not have excessive exposure to environmental sources of the element is less than 0.25 mg/L. For children it is less than 0.05 mg/L.

Prolonged exposure of lead, which is highly toxic, can cause permanent damage to the kidneys, liver and haematologic systems.
Children are more at risk because lead exposure can reverse their brain growth and cause irreversible damage to their overall well being.
The scientist said GSI has already collected eight blood samples from in and the surrounding areas of Korba coal field areas in Chhatisgarh to ascertain the heavy metal concentration amongpeople staying there.

"We are trying to understand the heavy metal concentration among the people living in Korba coal field areas. We will analyse the blood samples to find out the magnitude," he said.
GSI has also collected fly ash, soil and other sources of heavy metal which ultimately affect people, mainly the children, he added.