Indoor air pollution is associated with an increased risk of both chronic obstructive pulmonary disease (COPD) and decreased lung function, according to research* published today in the European Respiratory Journal. The European Lung Foundation (ELF) said the study had shown that exposure to polluted air might contribute to the ageing process – it “seriously harms human health by reducing life expectancy and making people more prone to developing chronic lung disease”.
An international research team, including several UK-based scientists, analysed data from the UK Biobank covering a total of 303,887 people aged 40-69 years to examine associations between pollution in people’s homes – particulate matter (PM2.5, PM10 and PM coarse) and nitrogen dioxide (NO2) concentrations, estimated using a validated air pollution model – and forced expiratory volume in one second (FEV1), forced vital capacity (FVC), the FEV1/FVC ratio, and COPD (FEV1/FVC < lower limit of normal).
They reported that higher exposures to each pollutant were significantly associated with lower lung function. A 5μg/m3 increase in PM2.5 concentration was significantly associated with lower FEV1 (‑83.13 ml) and FVC (‑62.62ml). They found that COPD prevalence was associated with higher concentrations of PM2.5 (odds ratio, OR 1.52 per 5μg/m3), PM10 (OR 1.08 per 5μg/m3), and NO2 (OR 1.12 per 10μg/m3), but not with PM coarse.
They also looked at the effect on these associations of people’s sex, age, obesity, smoking status, household income, asthma status, and occupations previously linked to COPD. They reported stronger associations with lung function for men, people from lower-income households, and "at-risk" occupations; and stronger associations with COPD for obese, lower income, and non-asthmatic participants.
The researchers pointed out that COPD prevalence among participants living in areas with PM2.5 concentrations above World Health Organisation’s annual average guidelines of 10μg/m3 was four times higher than among those exposed to passive smoking at home, and half that of people who have ever been a smoker.
They concluded: “This is one of the largest analyses to date to examine associations between ambient air pollution and lung function and COPD. Air pollutant concentrations were clearly associated with lower lung function and increased COPD prevalence with higher impacts in males, individuals from lower income households, those in occupations with adverse respiratory exposures and those who were obese.”
The ELF added that the current EU air quality limit for PM2.5 of 25μg/m3 is higher than the levels that the researchers noted as being linked to reduced lung function.
European Respiratory Society president Professor Tobias Welte from Hannover University, Germany, who was not involved in the study, commented: “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 Organisation 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.”
* Doiron D, de Hoogh K, Probst-Hensch N, et al. Air pollution, lung function and COPD: results from the population-based UK Biobank study. Eur Respir J 2019; in press.