Long-Term Air Pollution and Risk for COPD and Asthma in Women

Women exposed to air pollutants over a 20-year period have an increased risk for chronic obstructive pulmonary disease (COPD), a study in Environmental Research suggests.

Prospective cohort data from the Australian Longitudinal Study on Women’s Health were the focus of this study. Patients from 3 age cohorts were all women and were followed up to 21 years for incident COPD and asthma. Exposures to carbon monoxide (CO), nitrogen oxides, sulfur dioxide (SO₂), and particulate matters 2.5 and 10 were measured using the National Pollutant Inventory.

Inverse-distance weighted emissions in kilograms that women were exposed to from sources within a 10-km distance of their residences were identified. Adjusted analyses assessed the association between risk for self-reported doctor-diagnosed COPD and asthma with exposures to pollutants.

The total number of new COPD cases and new asthma cases were 3616 (11.5%) and 2725 (9.4%), respectively. Overall, women were exposed to a mean of 47 to 59 point sites with accompanying air pollution emissions. While fossil fuel electricity generation and mining provided the largest contributions to air pollution, the researchers found hundreds of other emission types in air pollution.

None of the emissions assessed in the Cox analyses were associated with the incidence of adult asthma. For each individual pollutant, there was no increased risk for asthma with exposure to CO (hazard ratio [HR], 1.006; 95% CI, 0.0990-1.022), nitrogen oxides (HR, 1.005; 95% CI, 0.987-1.022), particulate matter (HR, 1.004; 95% CI, 0.985-1.023), and SO₂ (HR, 1.005; 95% CI, 0.993-1.017). As a result of these findings, the researchers focused solely on the association between air pollution emissions and the incidence of COPD.

The CO, nitrogen oxides, SO₂, and particulate matters were individually associated with a higher risk for COPD after controlling for covariates. Factors associated with the risk for COPD included SO₂ exposure for younger (HR, 1.021; 95% CI, 1.001-1.047; P <.05), middle-age (HR, 1.019; 95% CI, 1.004-1.034; P <.01), and older cohorts (HR, 1.025; 95% CI, 1.004-1.047; P <.02). Greater exposure to motor vehicle traffic in the younger cohort was also associated with the risk for COPD (HR, 1.003; 95% CI, 1.001-1.005; P <.04).

Limitations of the study included women who self-reported diagnoses of COPD and asthma as well as the recruitment of women only in Australia.

Findings from this study “highlight the importance of reasonable and prudent efforts to reduce harmful air pollution emissions across the industrial landscape as a means to promote public respiratory health.”

Reference

Hendryx M, Luo J, Chojenta C, Byles JE. Air pollution exposures from multiple point sources and risk of incident chronic obstructive pulmonary disease (COPD) and asthma. Environ Res. 2019;179(Pt A):108783.