Parts of central-western and northern India saw an increase in air pollution than most of the country even when economic activities almost came to a standstill during the coronavirus-induced lockdown in 2020, a report says.
Scientists at Nainital’s Aryabhatta Research Institute of Observational Sciences (ARIES) investigated the influence of the cutoff of activities on the changes in the distribution of ozone, carbon monoxide and nitrogen di-oxide during the lockdown period.
Most parts of the country reported clean air as there was little industrial activity, construction and vehicular movement, which are the biggest sources of emissions.
India went into a lockdown in late March 2020 as first wave of coronavirus hit the country that saw more than 1.2 billion people confined to their home.
The study, published in the journal Environmental Science and Pollution Research, was led by Prajjwal Rawat, a senior research fellow at ARIES, along with research supervisor Manish Naja.
Scientists at ARIES, an autonomous institute under the Department of Science and Technology, utilised the EUMETSAT and NASA satellite observations for the years 2018, 2019, and 2020.
According to the study, ozone, carbon monoxide and NO2 showed an increase of about 15 percent over the central-western part of India.
Carbon monoxide showed a consistent increase (as high as 31 percent) of concentration at higher heights during the lockdown period.
In a statement, the Science and Technology Ministry said scientists found that regions in the central-western and north India were prone to higher air pollution exposure, hence exposed to greater risk of respiratory problems.
“In 2020, a complete nationwide lockdown was imposed over India to impede the spread of coronavirus disease. This enormously disrupted the economy with a single positive side effect, a short-term improvement in the air quality near the surface,” the ministry said.
The satellite-based observation of toxic trace gases — ozone, NO2 and carbon monoxide—near the surface and in the free troposphere mostly showed reduction of the pollutants over India, it said.
However, over some regions like western-central India, some parts of northern India, and Remote Himalaya, an increase of ozone and other toxic gases was observed. This could have aggravated respiratory health risks around those regions during the pandemic, the ministry said.
The long-range transport and downward transport from the stratosphere significantly increased ozone concentrations over north India during the lockdown, and remote regions like the Himalayas and coastal cities showed the bare minimum influence of lockdown in air quality, with a tendency to increase in criteria air pollutants, the study said.
According to the ARIES team, this study helped to identify the regions prone to higher air pollution exposure, hence could identify areas at a greater health risk.
The team previously, with scientists from the ISRO, showed INSAT-3D as a valuable Indian geostationary satellite to study ozone pollutants over India. However, for other criteria air pollutants such as NO2, SO2 and CO, India is lacking in space-based observations and need air quality monitoring indigenous satellite in orbit.(With inputs from PTI)