Data | Pollution levels decline in many Indian cities due to COVID-19 lockdown

The drop coincides with decreased public mobility

Updated - May 25, 2020 11:47 am IST

Published - May 25, 2020 02:59 am IST

A deserted view of Anna Salai in Chennai. File photo.

A deserted view of Anna Salai in Chennai. File photo.

Due to the COVID-19-related lockdown, global CO2 emissions in 2020 have dropped to levels last seen in 2006. Particulate matter pollution levels in select Indian cities exhibit a similar decline. The drop coincides with decreased public mobility in India following the lockdown.

COVID-19 | State-wise tracker for coronavirus cases, deaths and testing rates

However, the recent relaxations have led to a significant increase in activity.

Pollution drops across cities

The graphs show daily PM2.5 levels between April 1 and May 24 in 2019 (red colour) and 2020 (blue). Except Mumbai, other cities recorded significantly low levels of particulate matter pollution in 2020 compared to 2019 on many days during this period.

Viewing in app? Click to see graph.  

image/svg+xml020406002040606040200Apr. 13Apr. 28May 130204040200Apr. 13Apr. 28May 1301002003003002001000Apr. 13Apr. 28May 1301002002001000Apr. 13Apr. 28May 13020406080020406080806040200Apr. 13Apr. 28May 13050100150150100500Apr. 13Apr. 28May 13DelhiChennaiBengaluruHyderabadMumbaiAhmedabad

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Also read: Delhi pollution halved during first phase of lockdown: CPCB

Mobility trends

The chart shows the increase or decrease in visits and length of stay at places in India compared to a baseline value (left axis). The baseline is the median value for the corresponding day of the week during the 5-week period (January 3–February 6).

The chart uses anonymised location data from phones collated by Google. It also shows the cumulative COVID-19 cases in India (dotted line, right axis).

Viewing in app? Click to see graph.

image/svg+xmlBaseline7550250+50-50-100Feb. 23Mar. 22Apr. 19May 16ResidentialCases (in thousands)Grocery & pharmacyRetail & recreationParksWorkplaces

Lately, due to relaxations, visits to grocery & pharmacy stores (red line), workplaces (purple line) and transit stations (orange line) have increased significantly. Parks (yellow line) and retail and recreational outlets (blue line) have continued to remain inaccessible as most of them are still shut.

Notably, the relaxations have come amid a surge in COVID-19 cases .

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