Climate Change and Respiratory Health

Current Evidence and Knowledge Gaps

Tim K Takaro; Kim Knowlton; John R Balmes


Expert Rev Resp Med. 2013;7(4):349-361. 

In This Article


Heat and drought conditions prevailed across much of the USA in the summers of 2011 and 2012, and contributed to wildfire risks. The 2012 wildfire season had the third highest total burn area in records dating back to 1960 more than 9.1 million acres as of 30 November 2012—and the average fire size was the highest on record.[13] Fire frequency has increased in western US states in recent decades, partially in response to warmer spring and summer temperatures, reduced precipitation and snowpack, earlier snowmelt in spring, and prolonged summer fire seasons at higher elevations, trends projected to continue as climate change continues.[14] Smoke emissions can travel hundreds of kilometers downwind of fire areas, exposing people to a complex mixture of fine particles, ozone precursors, and other health-harming compounds.[15–20] One recent worldwide estimate is that 339,000 deaths annually may be attributable to landscape fire smoke.[17] Respiratory and cardiovascular hospital admissions and emergency room visits increase in response to wildfire smoke exposures, strongly associated with PM levels.[15,21] These health threats could increase in future as climate change exacerbates wildfire risks in many regions.[22]