Air Pollution Kills Over Two Million People A Year, Study
A new study reveals that over two million people die each year because of human-caused outdoor air pollution.
Furthermore, while previous studies have suggested that a changing climate can worsen the effects of air pollution and increase death rates, the study, published in the journal Environmental Research Letters, reveals that climate change has a minimal effect and only accounts for a small proportion of current deaths related to air pollution.
Researchers estimate that around 470,000 people die each year because of man-made increases in ozone. They also estimate that around 2.1 million deaths are caused each year by man-made increases in fine particulate matter (PM2.5) - tiny particles suspended in the air that can penetrate deep into the lungs, causing cancer and other respiratory disease.
"Our estimates make outdoor air pollution among the most important environmental risk factors 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," study author Jason West of the University of North Carolina, said in a statement.
However, researchers note that the number of these deaths that can be attributed to climate change since the industrial ear is relatively small. Researchers estimate that a changing climate results in 1,500 deaths due to ozone and 2,200 deaths related to PM2.5 each year.
However, climate change can affect air pollution in many ways. It can lead to local increases or decreases in air pollution. For example, temperature and humidity can change the reaction rates that determine the formation or lifetime of a pollutant, and rainfall can determine the time that pollutants can accumulate. Researchers say higher temperatures can also increase the emissions of organic compounds 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 climate change are likely to be a very small component of the overall effect of air pollution," said West.