In an unusual sequence of events around a research paper that claimed air pollution was responsible for reducing life expectancy in Delhi by six years, Environment Minister Prakash Javadekar not only condemned the study but said in an e-mailed public statement that “the timing of the release of the study seems to be motivated as it has been done at a time when Prime Minister Shri Narendra Modi is on a visit to the United States of America.”
Then within hours of the statement issued late evening, the Environment Ministry withdrew it. The Hindu has Mr. Javadekar’s original statement and withdrawal.
The study ‘Premature mortality in India due to PM2.5 and ozone exposure’ was first published by the peer-reviewed journal Geophysical Research Letters (GRL) on May 14, but was reported by some papers on Tuesday.
The paper was published by multiple authors led by Sachin Gudde at the Indian Institute of Tropical Meteorology (IITM), a Pune-based research institute, affiliated to the Ministry of Earth Sciences. Scientists from the National Centre for Atmospheric Research, Boulder, Colorado was also among the contributors to the study.
GRL is among the most prestigious journals in the field of earth sciences and scientists vie to publish in it.
The study sought to investigate how ozone and fine particulate matter (PM2.5) could impact mortality. “We estimate that PM2.5 exposure leads to about 570,000 premature mortalities in 2011. On a national scale, our estimate of mortality by chronic obstructive pulmonary disease [COPD] due to O3 exposure is about 12,000 people. The Indo-Gangetic region accounts for a large part (~42%) of the estimated mortalities. The associated lost life expectancy is calculated as 3.4 1.1 years for all of India with highest values found for Delhi (6.3 2.2 years). The economic cost of estimated premature mortalities associated with PM2.5 and O3 exposure is about 640 (350–800) billion USD in 2011, which is a factor of 10 higher than total expenditure on health by public and private expenditure,” it says.
‘Assumptions faulty’
A senior official in the Ministry of Earth Sciences told The Hindu that the study based its assumptions of mortality on a relationship between PM2.5 and respiratory diseases that “wasn’t strongly borne out.”Moreover the study extrapolated European data to Indian populations, which literally interpreted, could lead to unusually high figures. “We don’t endorse the study but at the same time scientists ought to have the freedom to publish their findings,” the same official added. The Central Pollution Control Board has said it will formally challenge the report later this week.
R Krishnan, Director, IIT-M told The Hindu that the paper was “withdrawn” from their ‘Research Highlights’ section of the institute’s website, a forum to showcase the institute’s most notable research papers. “There are some implications and results that are extremely sensitive and we have to be careful about what we convey,” he said in a phone conversation.
