On how she began her research about pollutants in the environment:
My main interest has been in child neurology. I was interested in this area because a large number of children in Delhi are exposed to lead.

When we have lead in low levels in the blood, that is around 10 micrograms per decilitre, it does not produce any major symptoms. But it does affect the child's brain development, intelligence, behaviour and his/her performance at school.

Therefore, the effects of lead are very subtle. But when its concentration in the body increases slowly, it produces more recognised symptoms. In Delhi, pollution from vehicles and from the industries are very high. This made me initiate my first project. This project, which was completed in 1994, was funded by the World Health Organisation and was supported by the ministry of environment and forests.

On her first project:
The findings of this study have not yet been published due to some problems. There is no place in Delhi where we could get reliable blood lead level tests done. That was the primary setback. Therefore, it Look time to finally conduct the tests to determine the blood lead levels among school children.

We couldn't do it at AIIMS as the instruments were not working. Then we tried the Indian Institute of Technology, and finally we had to go to Central Pollution Control Board (CPCB). It was with their help that we could finally complete our study.

The study was based on a comparison of blood lead levels in school children located in contrasting areas. Two types of school areas were selected. One was where the ambient air lead levels are the lowest recorded by CPCB monitoring data (Siri Fort area) and second was the area where the air lead levels are the highest (ITO) for Delhi. We approached schools in this area and similar age group children were selected for the study. A total of 100 students in each of the category comprised the study group.

On the findings:
My findings reveal that almost 64 per cent of the children had lead levels higher than 10 microgram per decilitre - which is the Centre for Disease Control (CDC) accepted safe limit for lead.

On the analysis of the findings:
We tried to compare the results of the two areas in the study. We found that the lead levels among children near ITO was higher.

However, even in the other area there was a significant amount of lead in the children. A possible explanation to this would be that one may reside in one place and may travel to another place.

On the sources of lead poisoning:
Lead in the air settles on the soil and vegetables. The other potential sources of lead are solders in lead pipes, certain kinds of taps that are used, water storage systems, and the use of unglazed pottery to store water, milk or curd.

On the target group:
It is certain that lead levels are higher in children. This is because children breathe more than adults. While playing in the soil, they put their hands in their mouth. So a lot of lead gets into their system. Hence they have higher chances of getting lead poisoning into their system.

On the immediate symptoms of lead poisoning:
Lead poisoning affects every part of the human body. Loss of appetite, vomiting, hypertension in adults and kidney problems are the major symptoms. Lead affects the enzyme system of our blood. It causes anaemia, affects the nervous system and lowers the Intelligence Quotient and causes behaviourial problems.

On the lack of awareness among doctors:
The most important thing is awareness among doctors. Students should be taught at a very young age about the effects of lead poisoning. If there is awareness at school level, the future generation can stay away from lead poisoning.

On what led her into research:
My personal experiences with children's problems and my inability to get a blood lead level test done prompted me to get into research by starting a project.

On her future projects:
We have launched a massive programme to screen about 5,000 children, pregnant women and high-risk groups for lead levels. We initiated the project with the department of science and technology (DST).

DST is buying a lead analyser so that there will always be a permanent facility at AIIMS to test blood lead levels. We have already tested 1,800 children. The study will be completed in a year's time. Apart from this, we also intend to screen police personnel who are always on the road.