Air pollution levels have declined dramatically in the last month with experts pointing to less traffic on the roads as schools shut and more people work from home.

Nitrogen dioxide readings from morning rush hour in the period before and after the measures were implemented, show an average 70 per cent drop.

Mark Scerri from the Institute of Earth Systems said: “It is difficult to quantify with what’s available, but my gut feeling is that closing down the schools, together with other measures to control the spread of COVID-19 have de facto decreased traffic flows and hence the level of the associated air pollutants.”

Nitrogen dioxide is a noxious gas emitted by motor vehicles.

Measures to control the spread of COVID-19 have de facto decreased traffic flows

Scerri took an average of the readings in the morning rush hour period between February 19 and March 15, which peaked at 70 μg/m3 and March 16 to 19, when the average high was 20 μg/m3

All schools, childcare centres, university and MCAST closed in Malta on March 13 as part of measures to prevent the spread of the coronavirus.

Times of Malta also examined the hourly data compiled by the Environment Resources Authority’s monitoring stations on two dates: February 19 and March 19.

In the time brackets between 7am and 7pm, Malta’s roadways were over 50 per cent less polluted on March 19 compared to the same day in February.

The biggest drop in nitrogen dioxide was reported at 7am, falling from 85.377 microgram per cubic metre (μg/m3) to 13.561 μg/m3 an 85 per cent percentage decrease.

This data also showed that the amounts of harmful particulate matter ejected from vehicle exhausts and the construction industry, also declined.

Both PM2.5 and PM10 particles were also down by up to 50 per cent or more compared to the same day in the previous month.

These particles are a mix of liquid and solid particles which are both harmful to those with chronic illnesses like asthma and bronchitis. In large amounts they create a haze in the air.

Atmospheric pollution researcher Raymond Ellul said on Friday said that it makes sense that a fall in pollution would be linked to a decline in economic activity and road use.

He added that the current situation of reduced pollution gives impetus to seriously address climate change.