Dr Manas Ray, lead author of biggest study on air pollution effects on Delhi kids, says that citizens of Delhi, especially school-age children, were suffering more from several health problems compared to their control counterparts. Excerpts from interview:
How did the study come about?
We [Calcutta National Cancer Institute] submitted the proposal for studies on health impact of air pollution on adults and schoolchildren of Delhi to Central Pollution Control Board. They sanctioned the project, signed the MoU with CNCI, and released the funds. In essence, CPCB sponsored both projects. CPCB provided us with air quality data at regular intervals, besides some infrastructural support in the form of permission to use their lab so that human samples could be tested immediately after collection.
Why did you decide to study the impact on children in particular?
Because they are the most vulnerable to Delhi air. We also wanted to create a database that can be used as a benchmark for future studies. For example, if you do not know the lung capacity of a child now, how will you know 10 years later if it has increased or decreased? We wanted to follow the kids in the long term as air quality changed and conduct studies of 10-15 years where we could actually analyse the health effects. That didn’t happen. Also, after the introduction of CNG, air pollution in Delhi did reduce substantially. But whether the improvement translated into better health of citizens was difficult to ascertain because there was hardly any comprehensive air pollution-related health data of the pre-CNG era.
How significant would you say your study was?
I don’t think a study of this scale — over 10,000 children over 36 schools — with modern statistical tools had been done in the past, or has been done even afterwards. The health effects of air pollution were thought to be restricted to respiratory health. We showed its association on multiple aspects of not only physical but mental health of children. At every stage, we eliminated factors like season, income levels, calorie intake of children using modern statistical methods. We found that when all factors other than air pollution were eliminated, there was a clear association with health of children.
How was the study carried out?
We made a team of 15 persons. Dr Twisha Lahiri (HoD, neuroendocrinology, CNCI) and I were the principal investigators. The duration of the study was initially only three years and 5,000 children but we were so excited with the findings that we worked for 5+ years and gave data on 10,000 children, after which the data was analysed which took another 3-4 years. We came from Kolkata by train every two months. We divided Delhi into some regions and 36 schools were chosen accordingly. We started our day at 8 am, met the local people, told them what is our purpose, who sent us (GoI was a big advantage). Then we arranged a makeshift medical camp, mostly at the roadside or inside a housing society… Our camp continued till evening or late night. Then we returned to CPCB Biolab and did tests till midnight with tea every hour.
How did the findings strike you?
From the first interim report, it was clear that the citizens of Delhi, especially school-age children, were suffering more from several health problems compared to their control counterparts. More importantly, most of these problems were positively associated with pollutants like PM10, PM2.5 in air after controlling potential confounding factors like age, gender, socio-economic status, tobacco habits, etc. In sum, Delhi’s higher air pollution was a significant contributing factor to adverse health outcome; children, women and the elderly were suffering more than the rest.
How did government react to your interim reports?
For the study, we only interacted with CPCB. We submitted our interim (first, second years) and final reports to them. People at the top of CPCB invited us to present the reports before the heads of departments, and even invited some Delhi Pollution Control Board heads to these meetings. We had the impression that CPCB was in close contact with MoEF, so it seemed that MoEF was aware of our findings and their implications. We were never invited to any MoEF meetings relating to policy reforms, if any.
Was there any follow-up on your recommendations?
In the reports, we made some practical and pointed recommendations, both short and long term. We hoped that even partial implementation will improve the situation. Unfortunately we are in complete darkness about the fate of these recommendations as nobody from the DPCB, CPCB or MoEF felt it necessary to contact or consult us in the matter. We gave specific recommendations on when children should go out and play, in what periods schools should conduct outdoor activities, what medical checks students should be subjected to and where schools should be constructed to escape vehicular air pollution. Absolutely nothing was followed up on. Nobody from the government ever contacted us.
How long did it take to publish your reports?
The reports came in the public domain after three years of submission to CPCB. We heard that the reports were sent to ICMR (Indian Council of Medical Research) and elsewhere for peer review. They ultimately found some experts who took their own time. After a year or two, the experts made the comment that it was a good study. Then the authority was convinced that the study was indeed not so bad, and decided to make it public —without any editing.
What is the next part of the study?
A follow-up is complete and with the CPCB since 2010 but they are yet to publish it. We realised during this study that health impact is not restricted to outdoor pollution, this pollution is now entering indoors. We found especially girls who start helping their mothers with cooking from a young age have high pollution-associated health risks. That is an explosive piece of research and we have published around 20 peer-reviewed publications, but CPCB is still to come out with its report.
♦ Principal co-investigator, Central Pollution Control Board study on effects of air pollution on Delhi children (started 2002, final report 2010, published 2012)
♦ Retired in 2014 as assistant director of Chittaranjan National Cancer Institute, Kolkata, governed jointly by health ministry and West Bengal health dept
♦At CNCI, was in charge of research and head of experimental haematology and neuroendocrinology
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