Researchers estimate over two million deaths annually from air pollution

Over two million deaths occur each year as a direct result of human-caused outdoor air pollution, a new study has found.

In addition, while it has been suggested that a can exacerbate the effects of air pollution and increase , the study shows that this has a minimal effect and only accounts for a small proportion of current deaths related to air pollution.

The study, which has been published today, 12 July, in IOP Publishing's journal Environmental Research Letters, estimates that around 470,000 people die each year because of human-caused increases in ozone.

It also estimates that around 2.1 million deaths are caused each year by human-caused increases in (PM2.5) – suspended in the air that can penetrate deep into the lungs, causing cancer and other respiratory disease.

Co-author of the study, Jason West, from the University of North Carolina, said: "Our estimates make outdoor air pollution among the most important for health. Many of these deaths are estimated to occur in East Asia and South Asia, where population is high and air pollution is severe."

According to the study, the number of these deaths that can be attributed to changes in the climate since the industrial era is, however, relatively small. It estimates that a changing climate results in 1500 deaths due to ozone and 2200 deaths related to PM2.5 each year.

Climate change affects air pollution in many ways, possibly leading to local increases or decreases in air pollution. For instance, temperature and humidity can change the reaction rates which determine the formation or lifetime of a pollutant, and rainfall can determine the time that pollutants can accumulate.

Higher temperatures can also increase the emissions of from trees, which can then react in the atmosphere to form ozone and particulate matter.

"Very few studies have attempted to estimate the effects of past climate change on air quality and health. We found that the effects of past are likely to be a very small component of the overall effect of air pollution," continued West.

In their study, the researchers used an ensemble of climate models to simulate the concentrations of ozone and PM2.5 in the years 2000 and 1850. A total of 14 models simulated levels of ozone and six models simulated levels of PM2.5.

Previous epidemiological studies were then used to assess how the specific concentrations of air pollution from the climate models related to current global mortality rates.

The researchers' results were comparable to previous studies that have analysed air pollution and mortality; however, there was some variation depending on which climate model was used.

"We have also found that there is significant uncertainty based on the spread among different atmospheric models. This would caution against using a single model in the future, as some studies have done," continued West.

Explore further

Europe-wide study finds long-term exposure to even low levels of air pollution increases risk of lung cancer

More information: 'Global premature mortality due to anthropogenic outdoor air pollution and the contribution of past climate change' Raquel A Silva et al 2013 Environ. Res. Lett. 8 034005
Journal information: Environmental Research Letters

Citation: Researchers estimate over two million deaths annually from air pollution (2013, July 11) retrieved 26 May 2019 from
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Jul 12, 2013
Make that "Over two million simulated deaths occur each year as a direct result of human-caused simulated outdoor air pollution, a new simulated study has found."
Some scientists just can't think outside the X-Box.

Jul 12, 2013
I haven't seen the data, but 2 million/yr sounds about right. More regulation of smokestacks might help.

Jul 14, 2013
A single death is a tragedy. Two million deaths is crony capitalism

Jul 15, 2013
A single death is a tragedy. Two million deaths is crony capitalism

And forty million deaths is ho-hum under the Utopian Soviet Socialist Republics, and that's chicken feed compared to their Oriental protégé.

Jul 15, 2013
Thats odd. The story doesnt include the following pertinent info from other news sources carrying the same story:

"It suggests that 2.1 million people die after inhaling fine sooty particles called PM2.5s generated by diesel engines, power plants and coal fires." (guardian)

-How come physorg? Some of us would want to compare this to the 0 deaths annually from nuclear energy.

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