The Central Pollution Control Board (CPCB) has dismissed a widely-cited international report which said India recorded the highest number of deaths because of exposure to surface-level ozone and that it has surpassed China as the deadliest in the world.
The State of Global Air report 2017, released in February, said the number of deaths due to ozone pollution increased from 43,480 in 1990 to 107,770 in 2015.
“As the most populous countries, India and China account for most of the ozone-attributable COPD ( chronic obstructive pulmonary disease) deaths across all years, but India accounts for much (about 67%) of the global increase since 1990. Over the last 25 years, India experienced a nearly 150% increase in ozone-attributable deaths, while China’s number remained about the same,” the study said.
The death toll in India was 13 times higher than Bangladesh’s, and 21 times higher than Pakistan’s, it claimed.
The same study also said India’s rapidly worsening air pollution is causing over 1 million people to die prematurely each year and is catching up fast with China in terms of deaths linked to dangerous air particles, known as PM2.5.
A senior scientist at the CPCB, India’s top pollution regulator, countered the study’s findings saying that surface ozone levels in India are within safe limits, adding that they had, in fact, fallen because of a dip in solar radiation.
“There is no violation of our standards. Anyone can say anything. I am not aware of their methodology but Ozone level is not exceeding so seriously in India,” Dipankar Saha, who is in charge of CPCB’s air lab, told Press Trust of India.
“It is exceeding in some places, some day. But it is not a routine phenomenon. You cannot link early deaths to Ozone. Moreover, solar radiation is reducing so Ozone formation will be less,” he said.
The CPCB is preparing its own report on the issue, according to Saha.
Last month, Union minister for state for environment Anil Madhav Dave also expressed scepticism over the findings by foreign studies, insisting that India should rely on data generated within the country.
Surface-level ozone is not the same as the ozone layer that protects the earth from the sun’s radiation but is formed because of a chemical reaction between nitrogen oxides and volatile organic compounds (VOCs) in the presence of sunlight. The main sources of these two reactants are industrial facilities, power plants and vehicular exhaust.
It is particularly harmful to children, the elderly and those suffering from respiratory ailments.
The permissible limit for ozone levels according to CPCB standards is 100 micrograms per metre cube (µg/m3) over eight hours. Data from the pollution control authority’s monitoring stations revealed that at two sites, Shadipur and Dwarka, ozone levels peaked at 164 (ug/m3) in May last year.
The State of Global Air report was issued jointly by the Health Effects Institute, a US-based research institute focused on the health impacts of air pollution, and the Institute for Health Metrics and Evaluation, a population health research centre in Seattle.