Chapter 5. Air Quality


Category Description

Indoor and outdoor air pollution are leading threats to human health (WHO, 2006b, p. 87). Air pollution is produced by the natural or human-caused release of harmful contaminants into the atmosphere (WHO, 2014a). Air pollution is a global issue, affecting individuals across all countries and socioeconomic groups (WHO, 2016a). The EPI uses three indicators to measure air quality: household solid fuels, PM2.5 exposure, and PM2.5 exceedance.

Particulate matter (PM) exposure is associated with significant adverse health effects (Kloog, Ridgway, Koutrakis, Coull, & Schwartz, 2013; WHO, 2016a). These particulates can penetrate the human lung, leading to higher incidences of cardiovascular and respiratory disease (Goldberg, 2008). Recent research suggests that around 5 million people die prematurely every year due to air pollution, accounting for approximately one in every ten deaths annually (World Bank & IHME, 2016). Reducing air pollution levels globally can therefore improve human health today and in future generations.

Indicators Included

Household solid fuels. We measure household air pollution (HAP) as the health risk posed by the incomplete combustion of solid fuels, using the number of age-standardized disability-adjusted life-years (DALYs) lost per 100,000 persons due to this risk.

PM2.5 exposure. As a measure of chronic exposure, we use the population-weighted average ambient concentration of PM2.5 in each country.

PM2.5 exceedance. As a measure of acute exposure, we use the proportion of the population in each year that is exposed to ambient PM2.5 concentrations that exceed World Health Organization (WHO) thresholds of 10, 15, 25, and 35 micrograms per meter cubed (µg/m3) (2016a). These four proportions are averaged to produce a summary of the distribution of exposure levels in the country’s population.

Air Quality Indicators

Household solid fuels

DALY rate

PM2.5 exposure


PM2.5 exceedance

% population