Air Pollution Decreases Lung Function

In COPD inflammation within the lungs makes it difficult to breath, it is the third leading cause of death around the globe, and the number of deaths due to COPD are expected to increase in the coming years, according to the Global Burden of Disease project. 

As published in the European Respiratory Journal in this study researchers from the University of Leicester investigated the dangers of air pollution and how it impacts respiratory health. 

“There are surprisingly few studies that look at how air pollution affects lung health,” said Anna Hansell. “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 affected participants’ risk of developing COPD.” 

To calculate air pollution levels of fine particulate matter, particulate matter, and nitrogen dioxide a validated air pollution model was used, and data was used from the Biobank study that include data from health questionnaires and spirometry lung function tests from over 300,000 exposed participants. 

The data was used to conduct tests to investigate the impact of long term exposure to different levels of pollutants on participant lung function; each increase of 5 micrograms per cubic meter of PM2.5 was found to correlate with decreased lung function that was comparable to that of 2 years worth of aging. 

Multiple tests were conducted to examine how long term exposure to higher levels of different pollutants were linked to lung function changes, and factors such as smoking status, second hand smoke exposure, age, sex, BMI and education among others were accounted for in analyses; further analyses examined whether working in occupations at increased risk for developing COPD impacted prevalence. 

Those that were exposed to PM2.5 levels higher than recommended levels set by the World Health Organization were found to have had a prevalence for COPD that was 4 times higher than those who lived in homes where second hand smoke is present. Lower income households were found to be more affected by outdoor air pollution compared to higher income households; lower income participants were found to be at twice the risk for lung decline and 3 times increased risk for COPD. 

“In one of the largest analyses to date, we found that outdoor air pollution exposure is directly linked to lower lung function and increased COPD prevalence,” said Hansell. “We found that people exposed to higher levels of pollutants had lower lung function equivalent to at least a year of aging. Air pollution had approximately twice the impact on lung function decline and three times the increased COPD risk on lower-income participants compared to higher-income participants who had the same air pollution exposure.”

“We accounted for participants' smoking status and if their occupation might affect lung health, and think this disparity could be related to poorer housing conditions or diet, worse access to healthcare or long-term effects of poverty affecting lung growth in childhood. However, further research is needed to investigate the differences in effects between people from lower- and higher-income homes."

The study was limited by exposure to pollutants in daily lives were not able to be tracked, additionally participants were generally wealthier and healthier than the general public, which may have resulted in underestimates in the links between air pollution and declining lung function. Further studies are being conducted to examine whether genetic factors may interact with air pollution and the effects on health. 

"The findings of this large study reinforce that exposure to polluted air seriously harms human health by reducing life expectancy and making people more prone to developing chronic lung disease. Access to clean air is a fundamental need and right for all citizens in Europe. Governments have a responsibility to protect this right by ensuring that maximum pollutant levels indicated by the World Health Organization are not breached across our cities and towns. Breathing is the most basic human function required to sustain life, which is why we must continue to fight for the right to breathe clean air." says Professor Tobias Welte of Hanover University and President of the European Respiratory Society.