Particles suspended in outdoor air contribute to acute lower respiratory infections and many other non-communicable diseases, such as cancer. Lung cancer contributes more to the global disease burden for all cancers than any other, and it is estimated that 5% of the lung cancer disease burden is attributable to outdoor air pollution (WHO 2006 and Cohen 2004). The 2008 EPI uses the Urban Particulates indicator to capture these risks. Urban Particulates measures the concentration of small particles, between 2.5 and 10 micrometers (PM 2.5 to PM10) in diameter, suspended in air. These particles are dangerous to human health because they are small enough to be inhaled and become lodged deep in lung tissue.
The dataset used for Urban Particulates accounts for exposure by using population-weighted PM10 concentration estimates in each country’s national capital and in cities with populations over 100,000.The updated dataset was provided by Kiran Pandey at the Global Environment Facility from the Global Model of Ambient Particulates.
The target for Urban Particulates is set at an annual mean of 20 micrograms per cubic meter, which is derived from an air quality guideline set by the WHO (WHO 2005). This target is set at the level needed to minimize the risk that outdoor air pollution poses to human health. It is not feasible to set a zero target because many areas globally contain background concentrations of small airborne particles. Instead, this target expresses the objective of bringing human contributions to air pollution to a realistic minimum.
