Air pollution can increase the threat posed by COVID-19

Breathing polluted air contributes to 7 million premature deaths each year and can increase the threat posed by COVID-19, according to the World Health Organization (WHO).

Air pollution has been declared a major public health emergency as nine out of every 10 people in the world, particularly those living in cities, breathe air that doesn’t meet WHO health standards.

“Air pollution is one of the biggest public health issues we are confronting today,” WHO Director of Public Health and Environment Dr Maria Neira says on the WHO’s latest Science in 5 video.

“Long-term exposure to air pollution will affect your immune system and therefore will make you more susceptible to any type of respiratory diseases. And obviously, COVID-19 is a respiratory disease,” she explains.

Air pollution takes many forms. Natural sources include things like fires, pollen and volcanoes, but many of the toxic particles we breathe are generated by human activity.

This includes rearing livestock and burning solid fuels for cooking, as is done in many poorer countries. Combusting fossil fuels to generate power, heat or cool buildings, for transport purposes or to meet other energy needs also contributes.

Tiny particles from these sources, known as particulate matter, are suspended in the air and inhaled into a person’s lungs. Extremely fine particles – those about one-thirtieth of the diameter of a human hair – can penetrate lung walls.

While estimates differ, WHO data shows that outdoor air pollution causes 4.2 million premature deaths a year, and breathing toxic indoor air kills 3.8 million.

Inhaling particulate matter into the lungs impacts the respiratory system, which can lead to conditions such as lung cancer, pneumonia, asthma and bronchitis.

More scientific evidence is emerging linking immune systems weakened by air pollution to an increased threat from COVID-19, too. But the damage doesn’t stop there.

“We know now that these toxic particles will come to our lungs and from there to the bloodstream and will reach our cardiovascular system,” says Dr Neira.

This can cause conditions like heart diseases, neurological disorders, strokes and reproductive system issues, she explains.

The easy answer is to stop burning fossil fuels and change to cleaner sources of energy, says Dr Neira. But that’s easier said than done.

Legislation can help countries enforce the WHO’s air-quality guidelines. And policy-makers can make changes at local or city level to introduce cleaner public transport systems, reduce the use of private cars, promote efficient energy use in buildings and encourage sustainable living.

Dr Neira’s advice is for individuals to push for action to tackle air pollution at a political level and ensure systems are in place to monitor the air quality they breathe every day.

“Tackling the causes of climate change will bring enormous benefits as well on reducing the causes of air pollution, therefore contributing enormously to our health,” she says.