Air pollution is likely to be increasing the number and severity of Covid-19 infections, according to the UK governmentâ€™s expert advisers.
In a report published on Wednesday, the experts said further investigation of the link between dirty air and the coronavirus pandemic was â€œurgently requiredâ€ and may be relevant to how the pandemic is managed.
The report also found that levels of nitrogen oxides, produced mainly by diesel vehicles, fell by 30-40% in urban areas during the lockdown, though they are likely to be rising again as the restrictions are eased.
The reports add to pressure on ministers to address the issue of air pollution and coronavirus, following calls from MPs for action and warnings from lawyers that the government has a legal obligation to urgently review its air quality strategy.
There is growing evidence from around the world linking exposure to dirty air to increased coronavirus infections and deaths, with some suggesting it plays a significant role. But ruling out other possible factors is complex and time-consuming, meaning a definitive conclusion is yet to be reached.
Exposure to air pollution is firmly linked to increases in respiratory and heart disease and these factors can increase the risk of severe Covid-19 symptoms, said Prof Alastair Lewis of the University of York, the chair of the UK governmentâ€™s independent science advisory group on air pollution. â€œGiven this, it would not be surprising if there was a link between exposure to air pollution â€“ past or present â€“ and the Covid-19 infection.â€
The section of the report on this issue was written by another government advisory group, the Committee on the Medical Effects of Air Pollutants, chaired by Prof Frank Kelly, of Imperial College London, and composed of 15 academic experts.
â€œAlthough there is, as yet, no clear empirical evidence that exposure to air pollutants increases the likelihood or severity of Covid-19 infection, knowledge of the impacts of air pollution on health suggests that this is likely,â€ the group concluded.
â€œPotential interactions between air pollution and Covid-19 may be relevant to the future management of the pandemic in the UK and elsewhere,â€ said the committee. Medical resources might be raised in polluted areas, for example.
Long-term air pollution may worsen the impact of Covid-19 on patients, while short-term pollution may irritate the lungs and increase the risk of infection. Traces of the virus have also been found in samples of air pollution, raising questions about airborne spread outdoors. â€œFurther investigation into all of the possible mechanisms is urgently required,â€ said the committee.
In June, lawyers acting for Mums for Lungs and the Good Law Project told ministers that the potential risk to life posed by air pollution during the pandemic means ministers must act even if the evidence is not yet conclusive. Dirty air is already estimated to cause 40,000 early deaths a year in the UK.
Ninety parliamentarians have also urged the government to back action on air pollution to help avoid a second wave of coronavirus, while an air pollution inquiry by a select committee of MPs is examining delays in the rollout of clean air zones in cities as a result of the pandemic.
The failure to consider air pollution as a factor in the higher rates of coronavirus deaths among minority ethnic groups, who are disproportionately exposed, was recently called â€œastonishingâ€ and â€œwholly irresponsibleâ€ by critics of a Public Health England review.