Introduction

The last two decades have seen a large body of evidence of substantial health effects for long-term exposure to air pollution – especially fine particulate matter – be it in the form of outdoor ambient air pollution (AAP) or household air pollution (HAP) from the use of solid fuels. There are compelling arguments that air pollution should feature in a new set of post-2015 development goals.

Global Health Effects and Exposure

to Air Pollution

Health Effects

Nearly six million deaths were attributed to AAP and HAP in 2010 according to the Global Burden of Disease (GBD) 2010 Project (Lim et al., 2012). This is more than from alcohol and drugs, about the same as from active and passive tobacco smoking, and four times more than from child and maternal undernutrition. Of 67 risk factors assessed, it is only surpassed by total dietary risk factors and high blood pressure, of which the latter is influenced by air pollution, tobacco smoking, and diet. The most recent estimates attribute 5.5 million (GBD 2013; Forouzanfar et al., 2015) to 6.5 million (WHO, 2016) deaths to air pollution.

The GBD 2010 Project developed an integrated PM2.5 exposure–response (IER) model to estimate these health effects by using relative risk (RR) information from studies of ambient PM2.5 air pollution, secondhand tobacco smoke, household solid fuel use, and active tobacco smoking (Burnett et al., 2014). The exposure–response relationships in the IER model are highly nonlinear withdeclining marginal relative risks of health outcomes at higher PM2.5 exposure levels.

Ambient Air Pollution Exposure

Nearly 90 percent of the world's population lived in areas with ambient outdoor PM2.5 concentrations exceeding WHO's AQG of 10 μg/m3 (annual average) in 2005, and nearly one-third lived in areas with ambient PM2.5 exceeding WHO's Level 1 Interim Target of 35 μg/m3 according to estimates by Brauer et al. (2012).

The highest annual average population weighted PM2.5 concentrations are found in a large belt extending from western sub-Saharan Africa (SSA-W) and the Middle East and North Africa (MNA) through South Asia (SA) to East Asia (EA) and the High Income Asia Pacific (HI AP) countries. Regional average population weighted exposures were below 10 μg/m3 in most of South America, the southern part of Africa, and in Australia and the Pacific Islands (Table 1.1).