The World Health Organization (WHO) recently released a report titled “Ambient Air Pollution: A global assessment of exposure and burden of disease”. Although pollution has been a hot topic for years and even decades, only recently have scientists and epidemiologists been able to team together to better understand the correlation between Ambient Air Pollution (AAP) and adverse health outcomes. The report ties together two main variables to assess air quality and burden of disease: mortality rates attributed to household and ambient air pollution, and annual mean levels of fine particulate matter (PM2.5).
The WHO report concluded that air pollution is responsible for an estimated 3 million annual deaths worldwide, and that exposure to particulate matter can result in acute lower respiratory disease, ischaemic heart disease, chronic obstructive pulmonary disease, lung cancer and/or stroke. The regions most affected by AAP are the Western Pacific and South East Asia, and the report suggests that low-income areas are most affected by poor air quality.
The two maps below illustrate this story. Figure 1 models the annual median concentration of PM2.5 in micrograms per cubic meter, where cooler colors indicate low PM concentrations and warmer colors indicate higher PM concentrations. As the map suggests, Africa, the Middle East and South East Asia show the highest levels of AAP.
Figure 2 shows the number of deaths per region. Light colors indicate fewer deaths, and darker colors indicate higher mortality rates. Notice that the regions with higher mortality rates also experience the highest levels of AAP, as illustrated in the first map.
The WHO report concludes that this is just the beginning of the discussion of pollution exposure and resultant burden of disease. There is still a severe lack in monitoring and reporting of both ambient air quality and health effects in low and middle-income regions.
Figure 1: Global map of modelled annual mean concentration of PM2.5 (in micrograms per cubic meter)
Figure 2: Deaths attributable to AAP in 2012