Some chemical compounds in our environment, known as phenols, are recognized for their potential harm to heart health. A recent study has shed light on their negative effects on the heart’s electrical functions.
Environmental phenols are present in many everyday products that we use regularly. They can be found in food preservatives, shampoos that contain parabens, and plastic containers with bisphenol A (BPA), which means people are frequently exposed to them.
Many environmental phenols are associated with heart toxicity. A new multidisciplinary research effort by four professors from the University of Cincinnati College of Medicine has revealed their harmful effects on how the heart conducts electrical signals, with findings presented in the journal Environmental Health.
“This is the first investigation into how phenol exposure affects the electrical activity of the heart in humans,” stated Hong-Sheng Wang, PhD, a professor in the Department of Pharmacology, Physiology, and Neurobiology and the lead author of the study.
The researchers analyzed data from the Fernald Community Cohort, encompassing nearly 10,000 individuals who lived in the vicinity of a former uranium processing facility operated by the U.S. Department of Energy at Fernald, near Cincinnati. These participants were part of the Fernald Medical Monitoring Program from 1990 to 2008.
Most individuals in the cohort were not significantly exposed to uranium beyond typical levels found in the general population. Wang and his team utilized biological samples and medical records from this group to ensure that uranium exposure did not influence their findings, thereby making them applicable to the wider population. Because urine samples and electrocardiograms (EKGs) were collected on the same day, the results were particularly relevant for studying the impact of environmental phenols.
The EKGs, which monitor the heart’s electrical activities, were analyzed by certified physicians, while the urine samples were sent to the Centers for Disease Control and Prevention for exposure assessments.
A key objective of the study was to detect any changes in EKG readings linked to exposure to environmental phenols.
The heart’s function is governed by electrical impulses, making any disruption to its electrical properties potentially harmful and possibly leading to irregular heart rhythms.
The study concluded that increased exposure to certain environmental phenols is linked with changes in cardiac electrical activity.
In women, higher exposure to BPA, BPF, and BPA+F was linked to a prolonged PR interval, indicating a delay in the transmission of electrical signals from the upper chambers to the lower chambers of the heart.
“Our results were notably gender-specific,” Wang commented. For women, the study found a connection between increased exposure and a longer QRS duration, which relates to the contraction timing of the ventricles and could indicate issues with the electrical signals of the heart.
“This connection was particularly evident in women with higher body mass indexes,” Wang added.
For men, increased exposure to triclocarban (TCC), a substance used as an antimicrobial, resulted in longer QT intervals, suggesting that the heart’s electrical system was taking too long to reset, which may lead to rhythm problems. TCC has since been banned in the United States.
Wang emphasized that typical levels of exposure to these substances alone are unlikely to trigger significant heart disease in otherwise healthy individuals.
“The changes we observed were not drastic, but moderate alterations in cardiac electrical activity,” he mentioned. “However, these changes were particularly pronounced in certain vulnerable populations.”
He noted that such changes in heart activity could worsen pre-existing heart conditions or arrhythmias, particularly in older adults or those with other risk factors.
“With the emergence of new chemicals, our next focus will be to assess these newer environmental compounds and investigate their individual impacts on those at risk for heart disease,” Wang stated.
Other researchers involved in this project included Susan Pinney, PhD, FACE, from the Department of Environmental and Public Health Sciences; Jack Rubinstein, MD, FACC, from the Department of Internal Medicine; and Changchun Xie, PhD, from the Department of Biostatistics, Health Informatics, and Data Sciences.
This research received funding from the National Institute of Environmental Health and the University of Cincinnati Center for Environmental Genetics.
