The latest available data on air pollution has prompted the World Health Organisation (WHO) to call for the implementation of effective air pollution mitigation policies, close monitoring of the situation in cities worldwide and greater awareness of health risks caused by air pollution.

Outdoor air pollution was responsible for the deaths of 3.7 million people under the age of 60 in 2012. According to WHO, indoor and outdoor air pollution combined are among the largest risks to health worldwide. “Too many urban centres today are so enveloped in dirty air that their skylines are invisible,” said Dr Flavia Bustreo, WHO Assistant Director-General for Family, Children and Women’s Health.

High concentrations of small and fine particulate pollution are particularly associated with high numbers of deaths. Measurement of fine particulate matter of 2.5 micrometers or less in diameter (PM2.5) is considered to be the best indicator of the level of health risks from air pollution. Africa was found to have a concentration of fine particulate matter smaller than 10 microns (PM10) of 78. Although considerably lower than the 208 PM10 in the Eastern Mediterranean and the PM10 of 128 in South-East Asia, it still has a higher concentration of PM10 than both America and Europe.

Addressing air pollution

“Effective policies and strategies are well understood, but they need to be implemented at sufficient scale. Cities such as Copenhagen and Bogotá, for example, have improved air quality by promoting ‘active transport’ and prioritizing dedicated networks of urban public transport, walking and cycling,” said Dr Maria Neira, WHO Director for Public Health, Environmental and Social Determinants of Health.

According to WHO, individual cities can take local action to improve air quality and thus go against regional trends. Measures include ensuring that houses are energy efficient, that urban development is compact and well served by public transport routes, that street design is appealing and safe for pedestrians and cyclists, and waste is well managed. Such activities not only clean the air but can also serve as a catalyst for local economic development and the promotion of healthy urban lifestyles, says WHO.

Despite the upswing in air quality monitoring, WHO says many cities in low and middle income countries still lack capacity to do so. There is a particular shortage of data in regions of Africa and the Eastern Mediterranean.