WASHINGTON (AFP) – Babies who are exposed before birth to ethyl benzene, a toxic component in crude oil, may have a higher risk of developing congenital heart disease, US researchers said Saturday.

Another chemical used as an industrial metal degreasing agent, trichloroethylene (TCE), also boosted heart risks, said the research to be presented at the Pediatric Academic Societies annual meeting in Denver, Colorado.

Congenital heart disease occurs when the heart is malformed before birth, and is the most common of all birth defects. Previous studies have suggested it could be caused by chemicals in the environment.

"Congenital heart disease is a major cause of childhood death and life-long health problems," said D. Gail McCarver, lead author of the study and professor of pediatrics at the Medical College of Wisconsin.

"Thus, identifying risk factors contributing to CHD is important to public health."

Researchers collected stool samples from 135 newborn babies with the heart condition and 432 infants without it. A full 82 percent of all the infants showed exposure to at least one of the 17 solvents measured in the study.

White, but not black, infants who showed exposure to ethyl benzene had four times the risk of CHD.

Black infants exposed to trichloroethylene showed an eight-fold risk for the heart condition, and white infants with the traces in their stool had a two-fold higher risk, said the findings.

"This is the first report that exposure to ethyl benzene, a compound present in crude oil, was associated with CHD," McCarver said, noting that more studies are needed to confirm the link.

Some residents of the US Gulf Coast have expressed concern about their health in the aftermath of the BP oil spill last year, though no studies have been completed yet to determine the effects of exposure to the spilled oil.

Other sources of ethyl benzene include vehicle exhaust, petrol pump vapors and cigarette smoke.

Image credit: Flickr commons.