PM2.5 levels drop in Wuhan, China


Quarantine in Wuhan gives a 40% drop in PM2.5 levels

The restrictions put in place to limit spread of the Corona (COVID-19) virus have significantly reduced air pollution in China. Measurements from ESA/NASA show a dramatic decline in nitrogen dioxide levels over China, unprecedented in recent history.

Wuhan pm2.5 histogram averages
PM2.5 levels before and after the quarantine of 23 Jan 2020. Averages calculated for periods 01 Dec 19-23 Jan 20 (before quarantine), and 24 Jan 20 – 11 Mar 20 (after quarantine).

Our own calculations from monitoring stations in Wuhan show an almost 40% reduction of PM2.5 average levels in the city.

Wuhan PM2.5 levels
Wuhan PM2.5 Levels before and after quarantine of 23 Jan 20. The blue line is a moving average of  approx 10 days from monitoring stations in Wuhan. Average before quarantine calculated 1. Dec 19-23 Jan 20, after quarantine 24 Jan 20 -11 Mar 20.

What can we expect in the rest of the world?

Authorities world-wide are starting to take action to limit the COVID-19 spread. Virtually the whole of Italy has been locked down and other European governments are following suit. Countries like South Korea and Singapore are already under quarantine measurements.

Travel restrictions not seen before in modern times are put in place, with the US travel ban from Europe as a prime example.

It takes little imagination to foresee a significant drop in all man-made emissions, from climate gases to particulate matter. We at Airmine will follow up on the air pollution levels as the pandemic develops. In the meantime, wash those hands.

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