Exposure to air pollution can speed up lung disease as much as smoking a pack of cigarettes a day, new research has revealed.
The study, published today (13 August) in JAMA, identifies a link between long-term exposure to major air pollutants â€“ especially ozone â€“ and an increase in emphysema, which causes shortness of breath and can be fatal.
Researchers found that being exposed to ozone levels 3ppb (parts per billion) higher than other locations for 10 years leads to increased risk of emphysema roughly equivalent to smoking a pack of cigarettes daily for 29 years.
The study also found that ozone levels are increasing by that amount in some major U.S. cities, partly due to climate change, with the annual average ozone levels of areas looked at by the study found to be between 10 and 25 ppb.
â€˜Rates of chronic lung disease in this country are going up and increasingly it is recognized that this disease occurs in nonsmokers,â€™ said Dr. Joel Kaufman, senior co-author of the study and professor of environment and occupational health sciences and epidemiology at the University of Washington.
â€˜We really need to understand what’s causing chronic lung disease, and it appears that air pollution exposures that are common and hard to avoid might be a major contributor.â€™
The extensive, 18-year study looked at over 7,000 people in six major metropolitan areas across the United States â€“ Chicago, Winston-Salem, Baltimore, Los Angeles, St. Paul, and New York â€“ and their air pollution exposure between 2000 and 2018.
The authors believe it is the first longitudinal study to look at the connection between long-term air pollution exposure and emphysema progression across several communities.
Researchers involved with the study assessed air pollution levels where the participants lived, collecting detailed measurements of exposures over years in their home region and even at many of their homes.
They also measured emphysema by looking at over 15,000 CT scans taken of participants, as well as lung function tests.
While levels of most air pollutants decreased during the 18-year study â€“ Â due to successful initiatives to reduce them – the study also found that levels of ozone – created when sunlight reacted with pollutants from fossil fuels â€“ are increasing.
Researchers have warned that ozone levels will continue to grow as global temperatures rise due to climate change, while it is still unclear what â€˜safeâ€™ levels of air pollution are.
The British Lung Foundation said the study adds to a â€˜stack of evidenceâ€™ that air pollution has a serious impact on lung health.
Dr Penny Woods, chief executive of the British Lung Foundation, said: â€˜Itâ€™s clear air pollution is dangerous, so we need the government to take this issue seriously and introduce bold policies to clean up our filthy air.â€™
The BLF has urged the government to commit to WHO guidelines for fine particulate matter and set out clear actions to meet them by 2030 in its upcoming Environment Bill.
A recent study also linked long-term ozone exposure to the development of heart diseases like atherosclerosis.