Research Communications

Heart hazards 

Environmental pollutants could be heart disease culprits

May 24, 2011

The leading cause of death in the United States and around the world, heart disease often occurs as the result of controllable risk factors such as smoking, hypertension, and diabetes. But some research suggests that 20 to 50 percent of heart disease patients don’t have these conventional causes.

Recent studies by Ohio University researcher Alexander Sergeev suggest another possible factor: persistent organic pollutants (POPs) such as pesticides, insecticides, and unintentional by-products from chemical reactions in factories. The list also includes polychlorinated biphenyls (PCBs), synthetic chlorinated compounds that were previously used in electrical equipment (such as capacitors and transformers), flame retardants, paints, and other products.

Heart Hazards
Photo Illustration: Christina Ullman.

“People know that smoking is a risk factor for disease, but they can make a choice to smoke or not smoke. If somebody resides in proximity to a source of POPs and has no idea about that, it makes it a very important involuntary risk factor,” he says.

Sergeev, a former Russian cardiologist who treated many heart disease patients, was intrigued by experimental animal studies that suggested that exposure to POPs causes atherosclerosis, a hardening of the arteries that decreases blood supply to the heart, resulting in a heart attack.

“If something causes atherosclerosis in a mouse, it’s reasonable to assume that it can also cause it in human beings, which would be relevant for people such as factory workers,” says Sergeev, an assistant professor of social and public health.

Sergeev began focusing on people hospitalized for heart disease and their proximity to sources of POPs. He analyzed large data samples through a program in the state of New York called SPARCS, the Statewide Planning and Research Cooperative System.

When patients leave a state-regulated hospital in New York, their information enters into a database. Sergeev studied 12 years of that data and compared it with the number of sources of POPs located in patient zip codes.

About 20 to 25 percent of the New York state population (not including New York City) lives in proximity to POP sources. These include hazardous waste sites and POP-contaminated bodies of water.

Sergeev found that living near POP sources is associated with a statistically significant increase—between 10 and 17 percent—of hospitalization for heart disease and stroke.

POPs raise particular concerns because of the length of time they can last in the environment. Some have half-lives of more than 100 years; something manufactured in 1970 could still exist in 2070.

 “POPs are persistent and can migrate in the environment,” Sergeev says.

By Katie Brandt

This story appears in the Spring/Summer 2011 issue of Perspectives magazine.