A study of more than 300,000 people has found that exposure to outdoor air pollution is linked to decreased lung function and an increased risk of developing chronic obstructive pulmonary disease (COPD).

COPD is a long-term condition to reduced lung function that causes inflammation in the lungs and a narrowing of the airways, making breathing difficult. According to the Global Burden of Disease (GBD) Project COPD is the third leading cause of death worldwide, and the  number of global COPD deaths are expected to increase over the next ten years.

Lung function normally declines as we age, but the new research published on July 9, 2019 in the European Respiratory Journal suggests that air pollution may contribute to the ageing process and adds to the evidence that breathing in pollution air harms the lungs.

Anna Hansell is Professor of Environmental Epidemiology in the Centre (this is how this word is spelled in the UK) for Environmental Health and Sustainability at the University of Leicester, UK, and was part of the research team. She said “There are surprisingly few studies that look at how air pollution affects lung health. To try and address this, we assessed more than 300,000 people using data from the UK Biobank study to examine whether air pollution exposure was linked to changes in lung function, and whether it affects participants’ risk of developing COPD.”

The researchers used a validated air pollution model to estimate the levels of pollution people were exposed to at their homes when they enrolled in the UK Biobank study. The types of pollutants the researchers investigated included particulate matter, fine particulate matter, and nitrogen dioxide, which are produced by burning fossil fuels from car and other vehicle exhausts, power plants and industrial emissions.

ASPIRIN STUDIED TO IMPROVE LUNG FUNCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin may lessen the adverse effects of air pollution exposure on lung function. The team of researchers from the Columbia Mailman School of Public Health, Harvard Chan School of Public Health, Boston University School of Medicine published their findings in the American Journal of Respiratory and Critical Care Medicine.

The researchers analyzed a subset of data collected from a cohort of 2,280 male veterans from the greater Boston area who were given tests to determine their lung function. The average age of participants was 73 years. The researchers examined the relationship between test results, self-reported NSAID use, and ambient particulate matter (PM) and black carbon in the month preceding the test, while accounting for a variety of factors, including the health status of the subject and whether or not he/she was a smoker. They found that the use of any NSAID nearly halved of the effects of PM on lung function, with the association consistent across all four weekly air pollution measurements from same-day to 28 days prior to the lung function test.

Because most of the people in the study cohort who took NSAIDs used aspirin, the researchers say the modifying effect they observed was mainly from aspirin, but add that effects of non-aspirin NSAIDs are worthy of further exploration. While the mechanism is unknown, the researchers speculate that NSAIDs mitigate inflammation brought about by air pollution.

Xu Gap. PhD, a post-doctoral research scientist in the Department of Environmental Health Sciences at the Columbia Mailman School said, “Of course, it is still important to minimize our exposure to air pollution, which is linked to a host of adverse health effects, from cancer to cardiovascular disease.”

Further studies are being performed to look at how basic human function and genetic factors  are affected by air pollution.

B VITAMINS

An earlier study by Baccarelli found that B vitamins may also play a role in reducing the health impact of air pollution.

NOTE: Continuous use of NSAIDs can cause side effects, such as internal bleeding.