Most of the nitrogen dioxide (NO₂) we breathe daily in our cities comes from motor vehicle exhaust. The Covid-19 lockdown effect on the NO₂ concentration in Madrid and Barcelona clearly demonstrated the anthropological causes behind city pollution.
Increasing awareness and accessing high-quality data are key steps to address the growing concern of air pollution in and outside cities.
During the lockdown period was clearly visible a decrease in NO₂ concentrations in Madrid attributable to reduction of traffic. Differences are particularly noticeable in peak hours, from 8 to 9 and from 19 to 20.
In the following viewers, original data sampling rate is 1 measurement/hour. The time lapse is a 48 hours moving average with a frame every 4 hours. Please note that the moving average enhance the visualisation of NO₂ trend concentrations and does not show the daily peaks.
Also in Barcelona, during the lockdown period a strong decrease in NO₂ concentrations was measured.
A strong decrease in pollution was already expected during the first days of the lockdown due to favourable meteorological conditions (i.e. rain, wind speed and direction).
Further analysis shown that before the lockdown period, the traffic in the central area of Barcelona (Eixample) contributed around 20 µg/m³ (40%) to local NO₂ concentrations. This contribution almost disappeared after March 14th when regulations were enforced.
Occur as a result of exposure to outdoor air pollution (OMS, 2021)
Lives in places where air quality exceeds World Health Organization guideline limits (OMS, 2021)
Are you interested in knowing more about urban air quality? Would you like to know how Lobelia Air high-quality data at street level resolution can help you?
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