Up to 33 million visits to the emergency department (ED) for asthma worldwide could be due to ozone or fine particulate matter air pollution, according to research in Environmental Health Perspectives.
Using epidemiological health impact functions combined with data on population, baseline asthma incidence and prevalence, and pollutant concentrations, researchers constructed a new dataset of national and regional emergency room visit rates among people with asthma using published survey data. To estimate the global levels of pollution, atmospheric models, ground monitors and satellites equipped with remote-sensing devices, were used.
Based on the data, the study authors estimate that up to 23 million annual asthma emergency room visits globally could be attributable to ozone, accounting for up to 20 per cent of annual asthma attendances to emergency departments. The fine particulate matter PM2.5 was estimated to account for further 5-10 million visits, representing 4-9 per cent of the annual number of global visits, respectively.
Environmental emissions were responsible for approximately 37 per cent of ozone impacts and 73 per cent of PM2.5 impacts. Remaining impacts were attributable to naturally occurring ozone precursor emissions for example from vegetation, and naturally occurring PM2.5 for example from dust and sea salt, although several of these sources are also influenced by humans.