Short term association between ozone and mortality: global two stage time series study in 406 locations in 20 countries

Ground level ozone is a highly reactive, oxidative gas commonly found in urban and suburban environments, mostly derived from anthropogenic emissions. Numerous epidemiological studies and several reviews from health and environmental agencies worldwide have reported that exposure to this pollutant is associated with adverse health outcomes, including increased short term mortality and morbidity. Evidence on the health impacts related to ozone exposure has important implications in climate change research, as ozone levels are predicted to increase with global warming. The objective of authors was to assess short term mortality risks and excess mortality associated with exposure to ozone in several cities worldwide.