UMDNJ identifies direct link between phthalates in plastics and inflammation in newborns

Jul 21 2010

Researchers at the University of Medicine and Dentistry of New Jersey (UMDNJ) have identified a direct link between phthalates, the substances that make plastics more pliable and durable, and inflammation in newborns - and are encouraging more limited use of the plasticizers. Their paper, "Inflammatory Effects of Phthalates in Neonatal Neutrophils," appears in the August 2010 edition of the journal Pediatric Research.

Previous studies have shown that premature babies are exposed to extraordinarily high concentrations of phthalates because of long-term exposure to phthalates in plastic medical equipment used during neonatal intensive care. These include multiple types of tubing, such as breathing tubes, feeding tubes, intravenous tubes, that these babies rely upon to survive. However, concern arises regarding the impact of that exposure on babies' health.

Anna M. Vetrano, Ph.D., adjunct assistant professor in the Department of Pediatrics, led a UMDNJ-Robert Wood Johnson Medical School team that conducted an in-vitro study examining whether phthalates can induce inflammatory effects in newborns. "That is important because many of the diseases unique to premature babies, including bronchopulmonary dysplasia - a chronic lung disorder - and necrotizing enterocolitis - an intestinal ailment, are triggered by, or associated with, excessive inflammation," she explained.

"This research identifies a common exposure to phthalates, something that we know is in high concentrations in these babies' bloods," said Barry Weinberger, M.D., associate professor of pediatrics and chief of the Division of Neonatology at UMDNJ-Robert Wood Johnson Medical School.

"We have direct evidence that the presence of phthalates prolongs the survival of white blood cells, which supports the idea that they are contributing to damage and to inflammation," Weinberger added. "We also found that phthalates encourage cells to produce hydrogen peroxide, which is used by the cells to kill germs. Hydrogen peroxide can be a very helpful in fighting infection, but, when produced in excess in the lung or the intestine, for example, it can kill cells and damage tissue."

It is important to pinpoint specific ways in which it might be beneficial to limit the exposure, the research team suggests. "The problem is that tubing and equipment are needed for the care of premature babies, so decreasing phthalates would not be a small change," Weinberger said. "As more and more evidence like this accumulates, we hope that it will trigger efforts to decrease the use of these compounds in the manufacture of products that are used for newborns' care."

Another area to consider: ways to treat the inflammation in babies. "There are FDA-approved anti-inflammatory drugs that could potentially treat or decrease these effects. Medications such as troglitazone are used now to treat inflammatory diseases in adults, and we have demonstrated that these drugs have the ability to reverse the inflammatory effects of phthalates in white blood cells," Weinberger said. "Therefore, we should look into this class of drugs to determine if it would be helpful to decrease inflammatory diseases in babies."

Prompted by these findings in newborns' cells, the UMDNJ-Robert Wood Johnson research team is conducting a clinical study examining babies' exposure to phthalates through the placenta during pregnancy. For this study, Weinberger's lab has teamed up with David Q. Rich, Sc.D., M.P.H., assistant professor at the UMDNJ-School of Public Health, to measure the concentration of phthalates and other environmental toxins in the urines of pregnant women during mid- to late-pregnancy and to analyze their effects in the cord blood of the babies. "We should be able to detect similar changes in cells that come right from the mother and baby," Weinberger said. These studies are funded by the New Jersey Department of Environmental Protection and the National Institute of Environmental Health Sciences' Center for Environmental Exposures and Disease in New Jersey, and the National Institute of Child Health and Human Development.