Common chemicals in consumer products are now linked to electrical changes in the heart

Environmental phenols are found in a wide range of common consumer products. They contain preservatives in packaged foods, parabens in shampoos and bisphenol A (BPA) in plastic tableware, so people are widely exposed to them day in and day out.

Some of these environmental phenols are known to have cardiac toxicity. Now, an interdisciplinary study involving four professors from the University of Cincinnati College of Medicine reveals their negative impact on the heart’s electrical properties, and the research has been published in the journal Environmental health.

“This is the first study to look at the impact of phenol exposure on heart electrical activity in humans,” said Hong-Sheng Wang, Ph.D., professor in the Department of Pharmacology, Physiology and Neurobiology and lead author of the study.

Researchers used data from the Fernald Community Cohort, which includes nearly 10,000 people who lived near the former U.S. Department of Energy uranium processing site in Fernald, outside Cincinnati, and participated in the Fernald Medical Monitoring Program between 1990 and 2008.

Much of the cohort did not experience uranium exposure beyond the radiation received by the general population. Wang and his team used their data, including biological samples and medical records, in the study so that uranium exposure would not play a role in the findings, making them relevant to the general population. Because urine samples and electrocardiograms, or ECGs, were collected on the same day, the results were significant for analyzing environmental phenol exposure.

The ECGs, which measure the heart’s electrical activity, were read by certified physicians and the urine samples were sent to the Centers for Disease Control and Prevention for exposure analysis.

One aim of the study was to identify any changes in EKG parameters associated with environmental phenol exposure.

The heart is powered by electrical activity, so anything that affects its electrical properties can have a damaging impact and possibly lead to cardiac arrhythmias.

The study concluded that higher exposure to certain environmental phenols is associated with altered electrical activity of the heart.

Researchers found that higher exposure to BPA, BPF and BPA+F in women is associated with a longer PR interval, a delay in the time it takes for electrical signals to travel from the atria at the top of the heart to the ventricles.

“Our findings were very gender specific,” Wang said. In women, researchers identified an association with longer QRS duration, or contraction of the ventricles, and dysfunction of the heart’s electrical impulses.

“It was especially pronounced in women with higher body mass indexes,” Wang said.

In men, researchers found that higher exposure to triclocarban (TCC), an antimicrobial agent, led to longer QT intervals in the heart, meaning the heart’s electrical system takes too long to recharge, a situation that can contribute to cardiac arrhythmias. TCC has since been banned in the United States.

Wang also pointed out that typical exposure levels alone are unlikely to cause clinically significant heart disease in healthy people.

“These were not dramatic changes that we observed, but moderate changes in the electrical activity of the heart,” he said. “However, they were particularly pronounced in certain subpopulations.”

He said the altered heart activity could worsen existing heart disease or arrhythmias in a patient, especially in older adults or in people with other risk factors.

“Now there are new chemicals on the market, so the next step would be to investigate these newer chemicals from the environment and focus on their impact at the individual level in those prone to heart disease,” says Wang.

Other contributors to this study included Susan Pinney, Ph.D., FACE, professor of epidemiology in the Department of Environmental and Public Health Sciences; Jack Rubinstein, MD, FACC, professor of clinical cardiology in the Department of Internal Medicine; and Changchun Xie, Ph.D., professor in the Department of Biostatistics, Health Informatics and Data Sciences.