Unhealthy air pollution impacts 99 per cent of people on Earth

People in low and middle-income countries suffer the highest exposures

Nearly every person on Earth is breathing harmful air pollution, the World Health Organisation (WHO) warned on Monday.

Unhealthy levels of fine particulate matter and nitrogen dioxide (NO2) are being inhaled by 99 per cent of the global population, with people in low and middle-income countries suffering the highest exposures.

WHO called for cuts in fossil fuel use on the same day as the United Nations’ Intergovernmental Panel on Climate Change, which found in its latest report that the world has less than three years to bring global carbon emissions into decline, and avert dangerous temperature rise.

WHO tightened its air quality guidelines in 2021 in an effort to help countries better evaluate air healthiness, and pollution which is linked to burning fossil fuels.

They include for the first time ground measurements of annual mean concentrations of NO2, a common urban pollutant and precursor of particulate matter and ozone. They also measure particulate matter, PM10 and PM2.5.

The WHO data was released in the run-up to World Health Day on 7th April.

The UN organisation estimates that there are 4.2 million deaths every year as a result of exposure to outdoor air pollution, and 3.8 million deaths annually due to smoke from dirty cookstoves and fuels in homes.

More than 6,000 cities in 117 countries now monitor air quality, WHO reports, almost a six-fold rise in the past decade.

In the 117 countries monitoring air quality, the air in 17 per cent of cities in high-income countries fall below WHO guidelines for PM2.5 or PM10. In low- and middle-income countries, air quality in less than 1 per cent of cities complies with recommended thresholds.

NO2 patterns are different, showing less difference between the high- and low- and middle-income countries.

Air pollution, even at low levels, can cause significant harm to the human body.

Particulate matter, especially the microscopic PM2.5, can lodge deep in lungs and enter the bloodstream, causing strokes along with cardiovascular and respiratory problems. There is emerging evidence that particulate matter impacts other organs and causes diseases including cancer.

NO2 is associated with respiratory diseases, particularly asthma, and symptoms like coughing, wheezing or difficulty breathing, increasing hospital stays and visits to emergency rooms.

“After surviving a pandemic, it is unacceptable to still have 7 million preventable deaths and countless preventable lost years of good health due to air pollution,” said Dr Maria Neira, WHO Director of the Department of Environment, Climate Change and Health.

“Yet too many investments are still being sunk into a polluted environment rather than in clean, healthy air.”

The WHO is calling on governments to take steps to reduce air pollution which in turn will also impact the climate crisis. These include bolstering the transition to clean energy for cooking, heating and lighting in homes, promoting public transport and pedestrian- and cycle-friendly networks, and enforcing stricter vehicle emission standards.

Improvements can also come from more efficient industry and municipal waste management, and reducing agricultural waste incineration and wildfires.

“High fossil fuel prices, energy security, and the urgency of addressing the twin health challenges of air pollution and climate change, underscore the pressing need to move faster towards a world that is much less dependent on fossil fuels,” said Dr Tedros Adhanom Ghebreyesus, WHO Director-General.