Researchers at George Washington University (GW) have estimated that up to 33 million asthma-related emergency room (ER) visits are triggered by exposure to ozone or fine particulate matter (PM2.5). While it has been long recognized that inhaling polluted air can trigger asthma attacks, this study is the first to quantify the effect of air pollution on asthma cases around the globe.
Study lead author Dr. Susan C. Anenberg is an associate professor of Environmental and Occupational Health at the GW Milken Institute School of Public Health.
“Millions of people worldwide have to go to emergency rooms for asthma attacks every year because they are breathing dirty air,” said Dr. Anenberg. “Our findings suggest that policies aimed at cleaning up the air can reduce the global burden of asthma and improve respiratory health around the world.”
Affecting around 358 million people, asthma is the most prevalent chronic respiratory disease in the world. The new research suggests that car emissions and other types of air pollution are severely increasing the frequency of serious asthma attacks.
Dr. Anenberg and her team started their investigation by examining emergency room visits for asthma in 54 countries and Hong Kong. The researchers then combined this data with epidemiological exposure-response relationships, and also with global pollution levels recorded by satellites.
The study revealed that between 9 and 23 million annual asthma emergency room visits may be triggered by ozone worldwide, while another 5 to 10 million asthma emergency room visits were linked to fine particulate matter.
Approximately half of the asthma-related emergency room visits attributed to air pollution occurred in South and East Asian countries, particularly across India and China.
In the United States, where the air is relatively clean compared to South and East Asian countries, ozone and particulate matter were estimated to contribute up to 33 percent of all asthma-related ER visits in the country.
Daven Henze is the principal investigator on the project and an associate professor at the University of Colorado Boulder.
“The value of using satellites is that we were able to obtain a consistent measure of air pollution concentrations throughout the world,” said Professor Henze. “This information allowed us to link the asthma burden to air pollution even in parts of the world where ambient air quality measurements have not been available.”
Dr. Anenberg concluded, “We know that air pollution is the leading environmental health risk factor globally. Our results show that the range of global public health impacts from breathing dirty air are even more far reaching–and include millions of asthma attacks every year.”
The study is published in the journal Environmental Health Perspectives.