80% of people living in urban areas are exposed to harmful pollution

Low-income cities are the most impacted by air pollution according to WHO findings

More than 80% of people living in urban areas that monitor air pollution are exposed to air quality levels exceeding World Health Organisation limits, increasing their risk of lung cancer and other life-threatening diseases.

While all regions of the world are affected, populations in low-income cities are the most impacted, the World Health Organisation (WHO) said in its latest report, as 98% of cities in low- and middle income countries with more than 100 000 inhabitants do not meet WHO air quality guidelines. However, in high-income countries, that percentage decreases to 56%.

In the past two years, the database – now covering 3000 cities in 103 countries – has nearly doubled, with more cities measuring air pollution levels and recognising the associated health impacts.

As urban air quality declines, the risk of stroke, heart disease, lung cancer, and chronic and acute respiratory diseases, including asthma, increases for the people who live in them.

“Air pollution is a major cause of disease and death. It is good news that more cities are stepping up to monitor air quality, so when they take actions to improve it they have a benchmark,” said Dr Flavia Bustreo, WHO assistant director general, family, women and children’s health. “When dirty air blankets our cities the most vulnerable urban populations—the youngest, oldest and poorest—are the most impacted.”

The report found that key trends from 2008 to 2013 included global urban air pollution levels increased by 8%, despite improvements in some regions. In general, urban air pollution levels were lowest in high-income countries, with lower levels most prevalent in Europe, the Americas, and the Western Pacific Region.

The highest urban air pollution levels were experienced in low-and middle-income countries in WHO’s Eastern Mediterranean and South-East Asia regions, with annual mean levels often exceeding 5-10 times WHO limits, followed by low-income cities in the Western Pacific Region.

In the Eastern Mediterranean and South-East Asia regions and low-income countries in the Western Pacific Region, levels of urban air pollution has increased by more than 5% in more than two-thirds of the cities. 

In the African region urban air pollution data remains very sparse, however available data revealed particulate matter (PM) levels above the median. The database now contains PM measurements for more than twice as many cities than previous versions.

“Urban air pollution continues to rise at an alarming rate, wreaking havoc on human health,” said Dr Maria Neira, WHO director, Department of Public Health, Environmental and Social Determinants of Health. “At the same time, awareness is rising and more cities are monitoring their air quality. When air quality improves, global respiratory and cardiovascular-related illnesses decrease.”

During the World Health Assembly, 23-28 May, Member States will discuss a road map for an enhanced global response to the adverse health effects of air pollution. 

WHO’s Air quality guidelines offer global guidance on thresholds and limits for key air pollutants that pose health risks. The Guidelines indicate that by reducing particulate matter (PM₁₀) pollution from 70 to 20 micrograms per cubic metre (μg/m), air pollution-related deaths could be reduced by roughly 15%.