A study of more than 300,000 people has linked prolonged exposure to air pollution to chronic lung disease and faster ageing.
In one of the largest studies of its kind to date, researchers in the UK have reported finding a direct link between exposure to outdoor air pollution and an increased risk of developing chronic obstructive pulmonary disease (COPD). Considered one of the leading causes of death worldwide, the disease causes inflammation in the lungs and a narrowing of the airways, making breathing difficult.
While declining lung function is expected as we age, a new study involving more than 300,000 people published in the European Respiratory Journal suggested that air pollution is speeding up this process. The data was obtained from a UK Biobank survey that measured changes in lung function and whether it affected their risk of developing COPD.
As part of the research, the study’s authors used a validated air pollution model to estimate the levels of pollution people were exposed to in their homes when they had enrolled in the UK Biobank study. The types of pollutants they looked at included particulate matter, fine particulate matter and nitrogen dioxide produced by burning fossil fuels from vehicle exhausts, power plants and industrial emissions.
Multiple tests were run to see how long-term exposure to higher levels of the different air pollutants was linked to changes in participants’ lung function. This showed that for each annual average increase of five micrograms per cubic metre of fine particulate matter in the air at home, the associated reduction in lung function was similar to the effects of two years of ageing.
Lower-income homes particularly affected
For those living in areas where fine particulate matter was 10 micrograms per cubic metre, prevalence of COPD was four times higher than among people who were exposed to passive smoking at home and half that of people who had ever been a smoker.
“Worryingly, we found that air pollution had much larger effects on people from lower-income households,” said Prof Anna Hansell of the University of Leicester.
“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.”
In trying to explain this, Hansell added: “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 researchers are also going to conduct further studies to see whether genetic factors interact with air pollution and its effects on health.