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Member Research & Reports

Member Research & Reports

BU Identifies Links between Ozone Levels and Hypertension Rates

Black women who live in neighborhoods with higher levels of ozone are more likely to be diagnosed with hypertension compared to women who live in neighborhoods with lower ozone levels, according to a new study led by Boston University School of Public Health (BUSPH) researchers affiliated with the Slone Epidemiology Center.

The study, in the American Journal of Hypertension, found that for every 6.7 ppb (parts per billion) increase in ozone levels, there was a 9 percent increase in hypertension incidence.  In contrast, higher levels of traffic-related nitrogen oxides (NO2) did not increase the risk of hypertension. The analysis was based on more than 33,000 women in 56 major US cities—participants in BU’s long-running Black Women’s Health Study who have been providing information on their health, including diagnoses of hypertension and other conditions, since 1995.

The study estimated levels of pollutants using validated models.  More than 9,500 of the 33,771 study participants, or 28 percent, reported incident hypertension during the study period, 1995 to 2011. The researchers controlled for a number of confounding factors, including weight, smoking, and socioeconomic status.

Lead author Dr. Patricia Coogan, senior epidemiologist at Slone and a research professor of epidemiology at BUSPH, said the study raises a new question that requires further research and confirmation.

“While we expected that NO2 would increase the risk of hypertension because it is a surrogate for particulate-bearing traffic pollution, the finding of a positive association of ozone levels with hypertension risk was unexpected,” she said. “This finding needs confirmation in other studies.”

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