Air Pollution From Wildfires Shows Link to Death Rates in Patients With Kidney Failure

Abhijit V. Kshirsagar, MD, MPH, the Covington Distinguished Professor of Medicine in the division of nephrology and hypertension, is a co-author of new research published in the Journal of the American Society of Nephrology that suggests individuals with kidney failure may face a higher risk of dying prematurely if they’re exposed to air pollution from wildfires

Air Pollution From Wildfires Shows Link to Death Rates in Patients With Kidney Failure click to enlarge Abhi Kshirsagar, MD, MPH

Wildfires generate high levels of tiny particles of air pollution—called fine particulate matter—that can have a range of effects on health. When inhaled, fine particulate matter can travel into the respiratory tract and bloodstream and trigger oxidative stress and inflammation. Because of their frailty, patients with kidney failure might be especially susceptible to this environmental stressor, but little is known about the effects of air pollution exposures in these individuals.

To investigate, a team led by Ana Rappold, PhD, US Environmental Protection Agency, and Yuzhi Xi, MSPH, UNC Gillings School of Global Public Health, analyzed information from 253 US counties near a major wildfire between 2008 and 2012.

“This study was possible because of the US Renal Disease System, a registry of patients with kidney failure included vital records on almost all US patients receiving in-center hemodialysis, as well as the zip codes of the dialysis clinics. Secondly, we utilized an air quality model to estimate daily exposure to wildfire fine particulate matter across the country at the zip codes of the dialysis units,” explained  Xi.

Researchers found 48,454 deaths among patients with kidney failure who were receiving dialysis in the 253 counties. Each 10 μg/m3 increase in the concentration of wildfire fine particulate matter in the air was associated with a 4% higher death rate on the same day and a 7% higher rate over the next month. On days with wildfire fine particulate matter greater than 10 μg/m3, exposure to the pollution accounted for 8.4% of daily mortality.

“These findings support the need for more research to develop and implement interventions to manage exposure to particulate matter during wildfire smoke episodes, in this population and others with a high prevalence of frailty,” said Kshirsagar.

Other co-authors include David B. Richardson, PhD, and M. Alan Brookhart, PhD with the Gillings School of Global Public Health,  and Timothy J. Wade, PhD, and Lauren Wyatt, PhD, from the EPA.

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