Air Pollutions Speeds Aging of Lungs, Increases COPD Risk

A recent study has found evidence that suggests air pollution may contribute to the aging process and adds previous studies that found breathing polluted air can harm the lungs. 


Investigators examined more than 300,000 and determined that ambient air pollution was associated with lower lung function and increased chronic obstructive pulmonary disease (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 Anna Hansell, MD, PhD, professor of environmental epidemiology in the Centre for Environmental Health and Sustainability at the University of Leicester, UK. “We found that people exposed to higher levels of pollutants had lower lung function equivalent to at least a year of ageing.”


The purpose of the study was to allow investigators to evaluate whether air pollution was associated with lung function and COPD. Additionally, investigators sought to explore potential vulnerability factors of the relationships between air pollution and lung function and COPD. 



Using a baseline questionnaire, anthropometric measures, and spirometry data from the UK Biobank collected between 2006 to 2010, investigators identified 303,887 individuals for inclusion in their analyses. Investigators categorized particulate matter (PM) into 3 distinct categories for analyses. Those categories were PM 2.5 (25 micrograms per cubic meter), PM 10 (inhalable particles 10 micrometers and smaller), and PM coarse.

Mean age of participants with complete data was 56 years and about 53% of participants were female. Investigators also noted that the majority of patients were overweight (43%) or obese (24%), had higher education qualifications (48%), and came from households earning over $35,000 (55%). 



Investigators found that 11% of study subjects had been diagnosed with asthma and 2% were employed in an occupation associated with an increased COPD risk. Additionally, COPD prevalence was 7%. 



After analyses, investigators noted that higher exposure to all pollutants showed significant associations with lower lung function. In models adjusting for variables such as age, sex, BMI, and smoking status, investigators found that a 5 µg/m3 increase in PM 2.5 concentration was associated with lower FEV1 (−83.13 mL [95%CI: −92.50, −73.75]) and FVC (−62.62 mL [95%CI: −73.91, −51.32]).

The prevalence of COPD was associated with higher concentrations of PM 2.5 (OR 1.52 [95%CI: 1.42, 1.62], per 5 µg/m3), PM10 (OR 1.08 [95%CI: 1.00, 1.16], per 5 µg/m3), and NO2 (OR 1.12 [95%CI: 1.10, 1.14], per 10 µg/m3), but not with PM coarse.

Investigators noted that stronger lung function associations were seen for males, individual from lower income households, and “at-risk” occupations, and higher COPD associations for obese, lower income, and non-asthmatic participants.

"Worryingly, we found that air pollution had much larger effects on people from lower income households,” Hansell explained. “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.”


This study, titled “Air pollution, lung function and COPD: results from the population-based UK Biobank study,” is published in the European Respiratory Journal.