HYDERABAD: Exposure of mercury, a toxic metal, to humans is a major health concern worldwide. Although India is one of the top mercury emitting countries in the world, there are hardly any adequate studies on how much mercury a person is exposed to on an average in the country.
A study in this direction was recently conducted by IIT Hyderabad to find out mercury exposure in three cities including Hyderabad in Telangana, Nellore in Andhra Pradesh and Vasco da Gama in Goa.
Globally, fish consumption has been identified as the most common way of mercury exposure among people and the IIT study shows that it stands true even in India.
The study recorded mercury exposure among vegetarians to be around 0.055 parts per million (ppm) as compared to 0.501 ppm among those who eat fish twice a day, 0.285 ppm among those who eat fish daily and 0.268 ppm among those who eat fish thrice in a week.
There is no reference value set by Indian authorities on what can be a safe level of mercury exposure, as per the US Environment Protection Agency, it is 1 ppm.
The study was conducted by KL Subhavana as part of her PhD for which hair samples from 650 individuals from the three cities were collected, as hair is a good indicator of mercury exposure.
While in most of the cases mercury exposure was seen to be either less or close to the 1ppm standard of USEPA, there were some cases where the mercury levels were well above the standard. The highest level of mercury exposure was recorded at 0.6 ppm in Hyderabad, 1.45 ppm in Nellore and 2.19 ppm in Vasco.
Dr Asif Qureshi of civil engineering department in IIT Hyderabad who guided the study says, “Thermal power plants are key mercury emitters and consumption of fish is a common pathway of mercury exposure. India is largely dependent on coal for power and has millions of people, especially on the coastline, who eat fish regularly.
There is a need for studying which species of fish among those commonly available in markets usually have more mercury content in them.” He added, “We are planning to conduct a study on mercury exposure among pregnant women, which can affect growth of infant in the womb.”