Stark difference: The current lockdown in India has caused steep reduction in particulate matter, as CPCB recorded reductions in pollutant concentrations across the board | Photo: CarbonCopy/Null School

Lockdown improved air quality across country, says CPCB

Around 80% of 115 cities recorded “good” and “satisfactory” in the Air Quality Index during the lockdown period compared to 44% cities before the lockdown was announced,  according to Central Pollution Control Board data from March 16 to April 15. Particulate matter (PM) and Nitrogen Dioxide (NO2) and Sulphur Dioxide (SO2) emissions fell drastically after the lockdown was announced on March 24, and vehicular traffic and industrial and commercial activities were highly restricted. In Delhi, data generated from continuous ambient air quality monitoring network was analysed from 38 stations; a 46% reduction in PM2.5 levels and 505 in PM10 was observed during the lockdown period. 

During the lockdown period, no city recorded ‘very poor’ AQI. However, a few cities recorded ‘poor’ AQI on some days.

Aerosol levels, tiny solid and liquid particles suspended in the air, some of which can potentially damage the human lungs and heart, were recorded at a 20-year-low over Gangetic plains in north India during early April according to NASA satellite imagery. Scientists compared aerosol optical depth (AOD) measurements over India between March 31 to April 5 for five years (2016-2020). AOD levels in north India at the beginning of April were significantly below the norm for this time of year and the lowest in 20 years, according to the study.

Delhi and Mumbai 2nd and 3rd most polluted in the world during lockdown: Study

Delhi and Mumbai ranked second and third among world’s 10 most polluted cities during the lockdown, according to Swiss-based air quality research body IQAir. Wuhan was the world’s most polluted city. The research collected real-time PM2.5 data from monitoring stations over the three-week lockdown. Mumbai’s PM2.5 levels dropped 42% on average between March 23 and April 13, compared to average PM2.5 levels (during the same period) over the past four years. Compared to 2019, the drop in PM2.5 levels was 34%. Mumbai’s PM2.5 concentration at 28.8 micrograms per cubic metre (μg/m³) during the lockdown period was the third-worst among the world’s 10 cities.

Wuhan, was the most polluted at 35.1 μg/m³ followed by Delhi, second most polluted at 32.8 μg/m³. New York had the lowest PM2.5 levels at 4.4 μg/m³, and had the cleanest air across 10 cities.

First evidence that air pollution particles carry COVID-19 emerges

The theory that air pollution particles could be harbouring and carrying the novel coronavirus has found some backing in preliminary scientific evidence emerging from the University of Bologna in Italy. Scientists used samples collected from one urban site and one industrial site in Bergamo province of northern Italy to look for the presence of the coronavirus. Upon analysis, a gene highly specific to COVID-19 was found in multiple samples indicating the presence of the virus on pollutant particles suspended in the air. The preliminary findings are yet to be peer-reviewed, and the longevity and transmissibility remain unknown.

Almost 80% of COVID-19 deaths in 4 countries of Europe occured in most polluted regions

Air pollution was “one of the most important” contributors to COVID-19 deaths in four countries of Europe, says latest research. Nearly 80% of the deaths attributed to COVID-19 in 66 administrative regions in France, Spain, Italy and Germany occurred in the most polluted regions. The research examined levels of nitrogen dioxide (emitted mostly by diesel vehicles) and weather conditions that can prevent dirty air from dispersing away from a city. Research says NO2 can cause lung disease, which could make people more likely to die if they contract COVID-19.

“The results indicate that long-term exposure to this pollutant may be one of the most important contributors to fatality caused by the COVID-19 virus in these regions and maybe across the whole world,” said Yaron Ogen, at Martin Luther University Halle-Wittenberg in Germany, who conducted the research. The researcher said it was now necessary to examine whether the presence of an initial inflammatory condition is related to the response of the immune system to the coronavirus.

Milan to redesign transportation system, cars to remain off streets post-lockdown

After the lockdown, Milan plans to reset the city’s old transport system, ban vehicular traffic and open the roads to pedestrians and cyclists. Cars will be off limits on at least 35km (22 miles) of the city’s streets. The city, located in the northern region of Lombardy, is among Europe’s most polluted regions and has been hit hard by the epidemic. Since the countrywide lockdown, vehicular traffic has dropped by 30-75%, bringing the air pollution down significantly.

Milan’s deputy mayor Marco Granelli said reopening of the economy will be done differently to the way it was before the lockdown. Janette Sadik-Khan, a former transportation commissioner for New York City, is helping Milan design the new transport system. Experts said the Milan plan will provide a playbook for how you can reset your cities now.