How air pollution risk ‘got WORSE during lockdown’

EMPTY roads during lockdown did nothing to reduce air pollution and Scots were left more at risk from being cooped up in their homes, scientists say.

Air pollution from cooking and second-hand smoke in the home is far more dangerous than vehicle emissions.

Despite a significant reduction in vehicle journeys during lockdown, levels of toxic fine particles in Scotland’s air were largely unaffected, according to experts at the University of Stirling.

They looked at levels of fine particulate air pollution which pose the greatest risk to health because they can penetrate deep into the lungs and even the bloodstream.

They have been linked to road vehicles, industrial processes and fires but can also be generated by tobacco smoke and cooking in the home, such as frying or roasting food, which gives off fine soot and organic particles.

The particles have been linked with breathing problems, heart conditions and aggravating asthma.

The researchers’ analysis of fine particulate air pollution in the first month of restrictions found little change – despite a 65 per cent reduction in the number of vehicles on the country’s roads. The team say their findings suggest that traffic is not a key contributor to outdoor air pollution in Scotland – and people may be at greater risk from air pollution in their own homes.

Dr Ruaraidh Dobson, who led the study, said: ‘It has been assumed that fewer cars on the road might have led to a decline in the level of air pollution outdoors and, in turn, reduced the number of cases of ill health linked to this pollution. However, our study – contrary to research from places such as Wuhan in China and Milan – found no evidence of fine particulate air pollution declining in Scotland because of lockdown.

‘This suggests that vehicles aren’t an important cause of this very harmful type of air pollution in Scotland and people may be at greater risk from poor air quality in their own homes, especially where cooking and smoking is taking place in enclosed and poorly ventilated spaces.’ The team analysed data from 70 roadside monitoring stations from March 24 – the day after lockdown was introduced in the UK – to April 23. They then compared the data to comparative 31-day periods in previous years.

They found that, across Scotland, the average concentration of fine particulate air pollution, known as PM2.5, was 6.6 micrograms per cubic metre of air in the observed period in 2020 – similar to the levels in 2017 (6.7 micrograms) and 2018 (7.4 micrograms).

The team did, however, note a reduction in nitrogen dioxide – specifically associated with vehicle exhaust emissions – in 2020, compared to the other three years.

But they believe personal exposure to potentially harmful air could have actually increased during the lockdown, due to people spending more time at home.

Dr Dobson added: ‘Lockdowns are intended to result in people spending more time in their homes. This could increase population exposure to indoor air pollution, such as cooking fumes and secondhand tobacco smoke.

‘In countries, like Scotland, where it appears that the lockdown has not led to reductions in outdoor fine particulate matter pollution, it is possible that personal exposure to PM2.5 may actually have increased rather than declined.’

‘Cooking fumes and second-hand smoke’