Study finds traffic not to blame for air pollution

Road traffic is not a major factor in outdoor air pollution, according to a new scientific study.

The number of vehicles on Scotland’s roads fell 65 per cent during the first month of lockdown this year but research shows this didn’t lead to any significant improvement in outdoor air quality.

A team from the University of Stirling analysed levels of fine particulate pollution – often referred to as PM2.5 – at 70 roadside monitoring stations across the country.

Data was gathered while the UK was in lockdown because of Covid-19 from March 24, 2020, to April 23,2020, and the results compared to similar periods from the previous three years.

Across the sites, the geometric mean concentration of PM2.5 was 6.6 micrograms per cubic metre of air in the 2020 period. This was similar to levels of 6.7 and 7.4 measured in 2017 and 2018, respectively, despite a substantial difference in the number of cars on the road.

Researchers says the 2019 level of 12.8 isn’t comparable because a meteorological event meant fine particulate dust from the Saharan desert impacted UK air quality, reports Auto Express.

Dr Ruaraidh Dobson, who led the study, says they found no evidence of fine particulate air pollution declining in Scotland because of fewer vehicles being on the road during lockdown – contrary to similar research in China and Italy.

“This suggests that vehicles aren’t an important cause of this very harmful type of air pollution in Scotland.”