The Covid-19 lockdown achieved 95% of the target set by India’s clean air programme in four major cities, holding important lessons to curb air pollution round the year

Clear sky over Bengaluru (Photo by Filip Jedraszak/Alamy)

India’s stringent lockdown to contain the Covid-19 epidemic led to a significant decline in air pollution levels in the major cities New Delhi, Mumbai, Kolkata and Bengaluru, according to a recent analysis.

From March 25 to June 8, four different phases of the lockdown showed a variety of restrictions being imposed on human-induced sources of air pollution that not only led to clean air but allowed researchers to carry out studies tracking base levels at mega cities in India that are affected by poor air quality.

Air monitoring start-up Respirer Living Sciences and non-profit Carbon Trends analysed concentrations of PM2.5, PM10, nitrogen dioxide, carbon monoxide, ozone and benzene, and found that the lockdown resulted in these four cities achieving 95% of their 2024 targets under the National Clean Air Programme (NCAP) in a short span of 74 days. PM2.5 refers to atmospheric particulate matter less than 2.5 micro metres (μm) that enters the human blood stream, severely affecting health.

The federal government notified the NCAP in January 2019 to achieve better air quality. NCAP seeks to reduce particulate matter pollution by 20-30% by 2024. Over the course of the year, 122 non-attainment cities were added to this list and air pollution action plans were developed and approved for 102 of them.

“The lockdown period helped us understand the effects from anthropogenic (human-generated) emissions to our environment,” said Ronak Sutaria, chief executive of Respirer Living Sciences. “All four cities analysed managed to better their 2024 NCAP target by around 30%, with Kolkata bettering their target by over 50% during the lockdown. This period is a marker for policymakers on how they can achieve what has been planned for in the coming four years, in a relatively shorter period.”

In January 2020, Carbon Trends launched an online dashboard, called the NCAP Tracker, to track the progress of NCAP. Respirer Living Sciences, a Mumbai-based start-up, builds real-time air quality monitoring networks. It has deployed air quality monitoring solutions in over 20 cities of India.

The tracker had earlier analysed PM2.5 and PM10 levels in New Delhi, Mumbai, Kolkata and Bengaluru in 2017, 2018 and 2019 to demonstrate the effectiveness of NCAP in bringing down pollution, taking levels in 2017 as the base year. While Kolkata saw an approximate 24% improvement in PM levels in 2019 in comparison to 2018, Mumbai averaged at 16%, Bengaluru at 19.8% and Delhi at 6.4%. These improvements fell short of the NCAP targets.

“The drastic reduction in pollutants across cities strengthens the fundamental need for managing air quality as a regional issue, across the same air shed, such that gains of clearer skies can happen along with growth and economic activity,” said Aarti Khosla, director, Climate Trends. “Lessons from the lockdown make it clear that city action plans need to be much more comprehensive in their strategy and approach to air pollution management.”

The drastic drop in pollution levels during the lockdown holds lessons in India’s air pollution management that need to be incorporated in achieving the country’s clean air targets. The levels can be brought down dramatically if India focuses its energy towards a green recovery model, which is less emission-intensive.