Did Kolkata’s Air Quality Improve in 2020?

How was Kolkata’s air quality in 2020? Did Kolkata’s air quality improve in 2020 compared to recent years? Air pollution in 2019 averaged levels nearly 7 times the World Health Organization’s (WHO) recommended limit for PM2.5 levels. Smart Air dove into the data to see if there was any improvement in 2020.

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Results: Did Kolkata’s Air Quality Improve in 2020?

After analyzing Kolkata’s air quality data from the US Embassy, Smart Air found that air pollution did not improve in 2020 compared to 2019. With an annual PM2.5 level of 67 micrograms, the citizens of Kolkata are still breathing an average of over 6 times the WHO annual limit.

Kolkata started the year with January pollution levels above 2019. Air pollution was also worse from September through November.

The Effect of COVID-19 Lockdown On Kolkata’s Air Pollution

Kolkata saw a big improvement in air quality during the COVID-19 lockdown. But thereafter, Kolkata’s pollution levels started peaking in the winter. PM2.5 levels in India typically begin to rise starting in October, and remain high until March of the next year.

Kolkata's seasonal pollution trend

With this bump up, Kolkata air pollution is inching closer to Delhi—currently the highest in air pollution among India’s major cities.

The analysis of Kolkata’s air quality is based on PM2.5 air pollution, particles smaller than 2.5 microns in diameter. These particles can penetrate deep into the lungs and even enter the bloodstream. Studies have found that PM2.5 raises blood pressure, inflammation, and rates of heart attacks and strokes.

PM2.5 size

The US Embassy data is open for researchers, although it is limited. It comes from only one pollution sensor in the city, and pollution can vary between neighborhoods.

Kolkata air pollution

Open Data

As always, Smart Air is publishing the test data for all fellow data nerds (Kolkata 2020 Pollution Data).

How I Protect Myself

Despite the harms of PM2.5, studies have found that wearing masks prevents physiological harm to the body. Also using air purifiers in your home have been shown to have positive effects on blood pressure, inflammation, and immune response.

Smart Air is a certified B Corp committed to combating the myths big companies use to inflate the price of clean air.

Smart Air provides empirically backed, no-nonsense purifiers and masks, that remove the same particles as the big companies for a fraction of the cost. Only corporations benefit when clean air is a luxury.

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Smart Air is a social enterprise that creates simple, no-nonsense air purifiers and provides free education to protect people’s health from the effects of air pollution. We are proud to be the only certified B-Corp dedicated to fighting air pollution.