Air pollution health effects

Air pollution health effects

Environmental epidemiologic studies worldwide have linked exposure to PM2.5 with various adverse health outcomes including respiratory and cardiovascular morbidity and mortality. These adverse health outcomes can be observed at relatively low PM2.5 levels measured in urban areas in the U.S. and Canada. In the developing world, ambient PM2.5 pollution is the 4th highest ranking risk factor in East Asia, the 6th in South Asia and the 7th in Africa and the Middle East, where mean PM2.5  levels are several-fold higher than in North America. Worldwide, WHO estimated that in 2012, 3.7 million deaths were attributable to ambient PM, ~88% of which occur in low- and middle-income countries.

Historically, population exposure to PM has been estimated using measurements made by expensive in situ monitoring stations. However, such monitoring networks are sparse or nonexistent in many parts of the world where PM concentrations are the largest. Even in the US, the ~1,200 stations operated by the EPA are located in only 30% of the nation’s ~3,100 counties.Lack of exposure estimates has been a serious limiting factor to evaluate its associated health outcomes in the developing world with little or no long-term surface monitoring.

Satellite-retrieved aerosol properties such as AOD have emerged as a promising solution to provide worldwide PM2.5 exposure estimates. Over the past decade, various satellite-based methods have been developed to estimate ground-level PM2.5 levels to effectively augment ground monitoring and help fill data gaps that impede efforts to study air pollution health effects. Working with several collaborators, our group has developed advanced exposure models to study the association between PM2.5 exposure and various health end points such as excess mortality, birth outcomes/defects, and type 2 diabetes.

Example: Odds ratios per 10 µg/m3 increase in satellite-estimated same-day PM­2.5 concentrations and ED visits for six pediatric health outcomes in Georgia, 1 January 2002 – 30 June 2010, stratified by county-level urbanicity (Strickland et al. EHP, 2016).

Example: heat maps showing the effects of ground and satellite remote monitored air pollution and absolute humidity on daily mortality in Beijing in 2006 (Wang et al. EI, 2013).