A group of U.S. medical researchers say in-vitro study tests show phthalate exposure has a greater adverse effect on immune system cells in newborns than adults.
The study, which focused on cells that normally work to fight infections by promoting inflammation, was published online July 20 in Pediatric Research medical journal. The research was conducted by the University of Medicine and Dentistry of New Jersey in Newark, which is part of Robert Wood Johnson Medical School.
The study also indicates that inflammation-promoting substances called cytokines are more attracted to immune cells in infants exposed to mono(2-ethylhexyl) phthalate, a metabolite of di(2-ethylhexyl) phthalate, or DEHP, researchers said.
But the American Chemistry Council in Arlington, Va., questions some of the findings.
“As the authors note, neonates (newborns less than 4 weeks old) have an increased susceptibility to inflammation to begin with — regardless of treatment,” said Steve Risotto, senior director of ACC's phthalates ester panel. “Bottom line, the study does not show that neonates exposed to higher levels of DEHP through medical treatment actually have a higher rate of inflammation than those who don't,” he said. “It merely suggests why they might.”
Still, some previous studies have suggested a possible link between phthalates and some inflammatory diseases to which premature infants are vulnerable.
“We have direct evidence that the presence of phthalates prolongs the survival of white blood cells,” said Barry Weinberger, associate professor of pediatrics and chief of neonatology at UMDNJ -Robert Wood. “We also found that phthalates encourage cells to produce hydrogen peroxide, which is used by the cells to kill germs. [But] hydrogen peroxide, when produced in excess in the lung or the intestine … can kill cells and damage tissue.”
Researchers concluded that “understanding the inflammatory effects of phthalates in neonates” is vital to determining whether there is a need to “limit the use of phthalate-containing medical devices in neonates.”