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Air pollution levels rising in many of the world’s poorest cities

More than 80% of people living in urban areas that monitor air pollution are exposed to air quality levels that exceed WHO limits. While all regions of the world are affected, populations in low-income cities are the most impacted.

According to the latest urban air quality database, 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 recognizing 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,” says 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.”

Global urban air pollution trends

WHO was able to compare a total of 795 cities in 67 countries for levels of small and fine particulate matter (PM10 and PM2.5) during the five-year period, 2008-2013. PM10 and PM2.5 include pollutants such as sulfate, nitrates and black carbon, which penetrate deep into the lungs and into the cardiovascular system, posing the greatest risks to human health. Data was then analysed to develop regional trends.

Key trends from 2008-2013:

  • 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.

Reducing the toll on human health

Ambient air pollution, made of high concentrations of small and fine particulate matter, is the greatest environmental risk to health—causing more than 3 million premature deaths worldwide every year.

“Urban air pollution continues to rise at an alarming rate, wreaking havoc on human health,” says 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.”

Most sources of urban outdoor air pollution are well beyond the control of individuals and demand action by cities, as well as national and international policymakers to promote cleaner transport, more efficient energy production and waste management.

More than half of the monitored cities in high-income countries and more than one-third in low- and middle-income countries reduced their air pollution levels by more than 5% in five years.

Reducing industrial smokestack emissions, increasing use of renewable power sources, like solar and wind, and prioritizing rapid transit, walking and cycling networks in cities are among the suite of available and affordable strategies.

“It is crucial for city and national governments to make urban air quality a health and development priority,” says WHO’s Dr Carlos Dora. “When air quality improves, health costs from air pollution-related diseases shrink, worker productivity expands and life expectancy grows. Reducing air pollution also brings an added climate bonus, which can become a part of countries’ commitments to the climate treaty.”

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%.

Notes to editors:

The WHO urban air quality database builds on well-established, public air quality monitoring systems as a source of reliable data in different parts of the world. National efforts to create operational and representative air quality monitoring systems should be strongly encouraged and supported.

The primary source of data include official reporting from countries to WHO, and official national and sub-national reports and web sites containing measurements of PM10 or PM2.5. Measurements reported by the following regional networks were used: the Clean Air Asia for Asia and the European Environment Agency for Europe’s Air Quality e-Reporting database. In the absence of data from the previous sources, data from UN and development agencies, peer-reviewed journal articles and ground measurements compiled in the framework of the Global Burden of Disease project were used.

Annual mean concentrations of particulate matter (PM10 and/or PM2.5) based on daily measurements, or data which could be aggregated into annual means, were included in the database. In the absence of annual means measurements covering a more limited period of the year were exceptionally used.

WHO Ambient Air Quality Guidelines

10 μg/m3 annual mean
25 μg/m3 24-hour mean

20 μg/m3 annual mean
50 μg/m3 24-hour mean

For more information, please contact:

Nada Osseiran
WHO Department of Public Health, Environmental and Social Determinants of Health
Telephone: +41 22 791 4475
Mobile: +41 79 445 1624

Kimberly Chriscaden
WHO Department of Communications
Telephone: +41 22 791 2885
Mobile : +41 79 603 1891



2016年5月12日 | 日内瓦 – 全球80%以上生活在监测空气质量的城市的人,呼吸着质量超出世卫组织限值的空气。虽然全世界所有区域都受到影响,但是低收入国家的人口受影响最大。




世卫组织家庭、妇女和儿童卫生事务助理总干事Flavia Bustreo博士说:“空气污染是造成疾病和死亡的一个主要原因。好消息是更多城市正在加紧监测空气质量,这样在采取行动改善空气质量的时候,它们就有了可以参照的标准。当肮脏的空气像毯子一样裹住我们的城市,最弱势的城市人群受影响最大,也就是最年轻、最年老和最贫困的人。”






世卫组织公共卫生、环境和健康问题社会决定因素司司长Maria Neira博士说:“城市空气污染继续以惊人的速度增加,严重破坏人类健康。同时,人们的意识也在提示,更多城市正在监测空气质量。空气质量改善,全球呼吸道和心血管相关疾病就相应减少。”




世卫组织的Carlos Dora博士说:“城市和国家政府使空气质量成为卫生和发展重点至关重要。空气质量改进时,与空气污染有关的疾病导致的卫生费用就会减少,工人的劳动生产率提高,预期寿命延长。减少空气污染还会带来额外的气候红利,这可以是各国对气候条约承诺的一部分。”












Nada Osseiran
电话:+41 22 791 4475
手机:+41 79 445 1624

Kimberly Chriscaden
电话:+41 22 791 2885
手机:+41 79 603 1891

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