Researchers took PM10 particulates captured in Marylebone Road and tested them on laboratory-grown human nose and throat cells.
They found that these airborne pollutants increased the body’s susceptibility to contracting the virus.
Professor Jonathan Grigg, lead researcher at Queen Mary University of London, said the early findings showed the importance of ongoing measures to clean up the capital’s air.
He said the nose was the “front door” through which the virus entered the body – and that pollutants could effectively widen the door by making the cells more of a target for covid.
This is because toxins increase the amount of an enzyme known as ACE2 on the surface of the cells in the nose and lower throat, making them more receptive to covid, probably for a “short-term period”.
Prof Grigg told the Standard: “Most people breathe through the nose. That means these cells are being exposed to the highest concentrations of pollutants in the environment.
“If a virus comes along in the one, two, three hours that this receptor is increased, you have got increased susceptibility. That increased ACE2 receptor means that more virus gets in.”
He said the study, which was funded with almost £50,000 from Barts Charity, showed a “plausible mechanism” linking environmental conditions and levels of covid infection.
It meant that in imposing the first lockdown, the Government had unintentionally “done the right thing” by advising people to stay at home and thus decreasing traffic.
Traffic levels have since risen above “normal” levels as Londoners avoid public transport. “We need to move to cleaner cars that produce less particles,” he said.
“We need to remove the most polluting of vehicles – diesel cars and vans which are producing a large proportion of nitrogen dioxide in the city. It may be that the extension of the ultra-low emission zone will do that.”
The Ulez is due to expand from central London to the North and South Circular roads by October next year, meaning drivers of older, more polluting vehicles will be charged £12.50 a day to use them.
The next stage of the study may be to swab people walking, cycling or driving in heavily polluted areas. This could also assess whether mask-wearing has a beneficial effect.
The charity funding was one of several “seed grants” to help provide insight into the pathology and impact of a number of conditions affecting the health of east Londoners, including covid.
Previously, data from existing epidemiological studies had been unable to provide clear answers to the question of whether breathing in pollutants increased the risk of disease.
Professor Grigg, an expert in paediatric respiratory and environmental medicine, said: “The importance of this work is that it aims to show that the association between exposure to increased fossil fuel pollution and increased vulnerability to Covid-19 reported in population studies is biologically plausible.”
Fiona Miller Smith, chief executive of Barts Charity, said: “We’re extremely pleased to support Professor Grigg’s work. East London was badly hit during the first wave of the pandemic, with Newham in particular taking the brunt.
“We also know that some of our roads and neighbourhoods are among the most polluted in the country and so we are potentially facing something of a dual threat to public health.
“By making this investment we hope to stimulate understanding that will not only protect our local community but have a positive impact right across the country.”
Source: Evening Standard Business News