The pollution level in India's five most-polluted cities, which are also in the top 10 globally, came down by over 50 per cent during the first 10 days of the lockdown imposed to combat COVID-19 outbreak, a new Greenpeace India analysis has found.
The study, released on Saturday, said these five cities - Ghaziabad, Delhi, Noida, Greater Noida, Gurgaon - witnessed a drop of over 50 per cent in their PM 2.5 concentration since March 24, when the nationwide lockdown was announced.
Particulate matters PM 2.5 are one of the primary reasons for health risks such as cardiovascular diseases, respiratory diseases, and lung cancer.
The analysis also said that strict implementation and inclusion of all non-attainment cities under the National Clean Air Program (NCAP) is crucial to address long-term air pollution problems.
The Greenpeace India report, which has also analysed Central Pollution Control Board data, said the PM 2.5 concentration level was down by 57.64 per cent in the national capital, by 65.75 per cent in Ghaziabad and 56.04 per cent in Gurgaon, among others.
"We can only use the COVID-19 outbreak as a lesson to mankind and once we pass the crisis, the country needs a coordinated and consistent action plan to address major sources of pollution that exist throughout the year to ensure a healthy planet for all," said Avinash Chanchal, senior campaigner, Greenpeace India.
Earlier this year, a report titled "World Air Quality Report 2019", published by IQ Air Visuals, revealed that five out of the top 10 most-polluted cities are located in India.
"Ghaziabad, which happened to be the most polluted city in the world, according to the report has witnessed 65.75 per cent reduction in PM 2.5 concentration from March 24 to April 4."
"Similarly, Delhi's PM 2.5 dropped by 57.64 per cent, Noida by 65.10 per cent, Gurugram by 56.04 per cent and Greater Noida by 68.83 per cent," the NGO report said.
Comparing these figures to 2019 data, the report said that last year during the same time period the air quality ranged between "Moderate" to "Unhealthy" and this year it has now been observed to be fairly "Good".
"Surprisingly, the cities which earlier fared among the top polluted ones, their air quality has been recorded to be below the prescribed National Ambient Air Quality Standards (NAAQS) of 60 micrograms per cubic meter (µg/m3). However the air quality of these cities are still much higher than the prescribed WHO standards of 25 µg/m3," it said.
According to the ''Toxic air: The Price of Fossil Fuels'' report released in February, air pollution from fossil fuel-related PM2.5 is attributed to an estimated 669,000 premature deaths each year in India.
In March a collective of doctors, The Doctors For Clean Air (DFCA), warned that people with compromised lung function could possibly have serious complications if infected by COVID-19.
The analysis said that human activities such as burning fossil fuels, transport, and the energy sector contribute significant quantities of particulate matter in cities and this can change by transitioning from fossils to renewables.
"The post Covid -19 government investment should focus on sustainability from the environmental perspective to protect the public health," said Mr Chanchal.
"Although we are witnessing a reduction in PM 2.5 across the cities because of the temporary slowdown of economic activities, we are aware that blue skies are unintended outcomes of the lockdown and it has come at the expense of a huge crisis that many are bearing the brunt of."
"This reduction in air pollution is temporary. It is worth noting that despite the lockdown, these most polluted cities are still not meeting the WHO prescribed air quality standards, which clearly means that we need a comprehensive study of sources of pollutants," he added.
Recently, the Central Pollution Control Board (CPCB) released a report on effect of "Janata Curfew" on the air quality in which it found that the reduction in number of on-road vehicles, resulted in up to 51 per cent reduction in nitrogen oxide (NOx) levels and 32 per cent reduction in carbon dioxide (CO2) levels during March 22-23, 2020 as compared to March 21.