Residents in high-poverty areas more susceptible to respiratory effects of ozone exposure

Former and current smokers living in high-poverty neighborhoods may have an increased risk for adverse respiratory effects of ozone exposure.

Daniel C. Belz, MD, MPH, postdoctoral fellow in the division of pulmonary and critical care medicine at Johns Hopkins University, and colleagues analyzed data from the SPIROMICS AIR study to evaluate the relationship between ozone exposure, COPD respiratory outcomes and neighborhood poverty. The analysis focused on 1,875 former and current smokers (mean age, 64.5 years; 79% white; 46% female; mean FEV₁, 74.4%). The researchers analyzed data obtained at study entry, including St. George’s Respiratory Questionnaire scores, COPD Assessment Test scores, modified Medical Research Council dyspnea scale, 6-minute walk distance, CT metrics and history of exacerbations. Spatiotemporal modeling estimated 10-year historical ozone concentrations outside of each participant’s home. Neighborhood poverty was defined by the percentage of households living below the 11.8% federal poverty level based on results of the 2010 U.S. Census.

“Our research group recently published a study that found that long-term exposure to ozone air pollution was associated with shortness of breath, but also with reduced lung function, and respiratory exacerbations for people with a history of heavy smoking, including people with COPD,” Belz said in a press release. “The current study shows that these effects were worse for people living in low-income neighborhoods, even if they were exposed to the same amount of ozone as someone living in a higher-income neighborhood. This was true even when we accounted for factors like age, race and personal income. These results suggest that certain aspects of someone’s neighborhood — lack of green space, poor housing quality, limited access to health care — can significantly affect their susceptibility to air pollution from ozone.”

According to the results, the researchers found a significant association between neighborhood poverty and increasing ozone concentration with respiratory outcomes, COPD Assessment Test, modified Medical Research Council dyspnea scale, 6-minute walking distance, percent air trapping, COPD exacerbation risk and risk for severe COPD exacerbation (P < .05 for all).

The adverse effects of ozone exposure were greater among individuals living in high poverty neighborhoods. The researchers reported an 81% increase in risk for COPD exacerbation with each 5 parts per billion increase in ambient ozone concentration in the highest-poverty neighborhoods (OR = 1.81; 95% CI, 1.4-2.4; P < .0001); however, they found no association in the lowestpoverty neighborhoods (OR = 1.09; 95% CI, 0.9-1.4; P = .44). The risk for COPD exacerbation in individuals living in high-poverty neighborhoods persisted after adjustment for individual factors such as age, sex, race, smoking status and duration, education, income and BMI.

“This study helps us understand that the same level of air pollution from ozone can have a more significant effect on people living in low-income neighborhoods,” Belz said.

The researchers suggested that “community level factors should be considered when assessing individual risk for respiratory outcomes in COPD and that addressing morbidity in high poverty areas may require community-level interventions.”

References:

Belz DC, et al. Am J Respir Crit Care Med. 2020;201:A6225.