WEDNESDAY, Oct. 8, 2025 (HealthDay News) -- Higher exposure to long-term air pollution may worsen symptoms of sleep apnea, according to a study presented at the annual congress of the European Respiratory Society, held from Sept. 27 to Oct. 1 in Amsterdam.Martino Pengo, M.D., Ph.D., from the University of Milano-Bicocca in Italy, and colleagues investigated the association between long-term exposure to particulate matter (PM10) and obstructive sleep apnea (OSA) severity in 25 different European cities. The analysis included data from 19,325 patients integrated with data of PM10 concentrations extracted from the Copernicus Atmosphere Monitoring Service.The researchers found that a one-unit increase in long-term PM10 exposure was associated with a 0.41 increase in the apnea hypopnea index. There was no association for peripheral oxygen saturation or the percentage of time during sleep that a person's blood oxygen saturation drops below 90 percent. There were significant regional differences in both intensity and impact of association."Even after we took account for other factors that we know have an effect on OSA, we still found an average increase in the number of respiratory events per hour of sleep of 0.41 for every one-unit increase in PM10," Pengo said in a statement. "This effect may seem small for an individual, but across entire populations it can shift many people into higher-severity categories, making it meaningful from a public health perspective."Press ReleaseMore Information.Sign up for our weekly HealthDay newsletter