Less transport, less factories…, since the introduction of containment measures in Morocco, a drop in the concentration of the main pollutants ranging from 10% to 60% has been noted.
Like many countries in the world, Morocco has seen its air quality improve after the declaration of a state of health emergency.
According to data provided by the air quality service to the National Meteorological Directorate (DMN), a decrease in the concentration of the main pollutants measured has been noticed.
The reduction rates of pollutants from road traffic emissions are between 30 and 60%, especially for nitrogen dioxide (NO2), carbon monoxide (CO) and fine particles whose diameter does not exceed 10 µm (PM10).
The concentrations of pollutants resulting from industrial activities, such as sulfur dioxide (SO2), have decreased by between 10 and 30%.
The decrease is general and observed in all the air quality measurement points, confirms to us the air quality service of the DMN.
A supervision and forecasting system
An air quality monitoring network is installed in several regions of Morocco. It currently has 29 stations. A permanent air quality monitoring and control committee is set up in each of them. It provides cadastres describing the spatial distribution and the temporal evolution of atmospheric emissions.
In Casablanca, the National Meteorology Directorate started in 2012 the implementation of a high resolution air quality monitoring and forecasting system. Indeed, an index provides daily data on the air quality in the agglomeration.
Since the introduction of the state of emergency, the index is no longer available, since several factories whose emissions are taken into account are stopped, explains to us a source of the quality service of the air of the DMN.
Less emissions in the world
Images recently released by NASA have shown a significant drop in pollution in China, linked, in part, to the drop in activity due to the pandemic.
In February, the concentration of nitrogen dioxide (NO2), produced mainly by vehicles and thermal power plants, fell in Wuhan, the epicenter of Covid-19.
The same phenomenon was observed in early March by the European Space Agency in northern Italy, a confined area to combat the spread of the virus. It would also occur in Madrid and Barcelona, where containment has been in place since mid-March, according to the European Environment Agency.
In the United States, nitrogen dioxide pollution has fallen by 30% in recent weeks, according to the latest observations from NASA.
The year 2020 would thus have observed the lowest levels ever recorded in the New York region since the start of NASA satellite recordings in 2005.
Nevertheless, scientists call for caution. Nitrogen dioxide levels fluctuate with the weather.