University of Louisville researchers have discovered that longer periods of exposure to air pollution have measurable negative effects on the heart and overall health.
Based on analysis of data from multiple studies of heart rate variability and pollution, researchers in UofL’s Christina Lee Brown Envirome Institute determined that after about three hours of exposure to pollution, there is a small but significant decline in heart rate variability (HRV). HRV is a key measure of the nervous system stress response and contributes to the regulation of the heart. Lower HRV has been linked to a higher risk of heart disease and cardiac events.
Cameron Stopforth, postdoctoral researcher, and Rachel Keith, associate professor of medicine, and their colleagues analyzed data from 27 published studies that together, suggest exposure periods of three hours to low levels of poor air quality may be enough to stress the nervous system and the regulation of the heart. These short-term shifts can provide an early warning of physiological stress that may affect long-term heart health.
“Our findings suggest the body may only compensate for poor air quality for so long.” Stopforth said. “After about three hours at low levels of exposure, HRV declines more rapidly which is a sign that the heart is coming under increasing physiological stress.”
Stopforth and Keith believe this research can help in designing new studies or interventions to better understand the impact of air pollution on individuals working outdoors and those with existing health conditions. Their analysis was published in BMC Public Health.
For real-time air quality monitoring and health guidance, please use the Louisville Metro Air Pollution Control District’s air quality map. The EPA also hosts a website showing air quality index readings across the U.S.
