Chemicals Lurking in the Cupboards

Common household chemicals may weaken children's immune response to vaccinations

(RxWiki News) Children with more exposure to PFCs, chemicals found in many household products, may not get enough protection from vaccines because of the chemicals' effects on their immune system.

A recent study reveals that higher levels of perfluorinated compounds, commonly called PFCs, present in children's blood both before and after birth, are associated with a lower antibody response to childhood immunizations.

"Keep your children up to date on their immunizations."

PFCs are common in a wide range of food packaging and familiar household products, such as Teflon, Scotchguard, Stainmaster and Gore-Tex.

Most Americans have some level of these chemicals in their bodies because they are so commonly used in manufacturing.

Dr. Philippe Grandjean, of the Harvard School of Public Health, led the study that investigated how well children developed antibodies to the diphtheria and tetanus vaccines, commonly given in the DTaP shot, compared to how much PFC concentration was in their blood.

Grandjean's study started with 656 children born in the Faroe Islands, a country in the Norwegian Sea between Scotland and Iceland, between 1999 and 2001.

They chose the Faroe Islands because its residents eat a lot of seafood, which is associated with higher exposure to PFCs.

Researchers measured the concentration of PFCs in the mother's pregnancy serum and then tested the 587 kids who completed the study at age five and age seven.

They found that children with higher concentrations of PFCs also had lower concentrations of antibodies for tetanus and diphtheria after they had received all their shots.

"We were surprised by the steep negative associations, which suggest that PFCs may be more toxic to the immune system than current dioxin exposures," Grandjean said.

Kids with double the concentration of three specific PFCs together had about half as much antibody concentration - which translates to about half the immunity of kids without those high concentrations of PFCs.

Some children's antibody concentrations were so low that they may not have long-term protection against the diseases the immunizations protect against.

Even after researchers controlled for the children's exposure to PFCs in the womb, they found that five-year-olds having twice the amount of two PFCs in their bodies were twice as likely to have too few tetanus antibodies and four times likely to have too few diphtheria antibodies to be effectively protected from those diseases two years later, when they were seven years old.

"Routine childhood immunizations are a mainstay of modern disease prevention," Grandjean said. "The negative impact on childhood vaccinations from PFCs should be viewed as a potential threat to public health."

Previous studies with mice had shown a reduced immune response after exposure to PFCs, but there was not much reliable similar data on humans.

"If the associations are causal, PFC exposure may increase a child's risk for not being protected against diphtheria and tetanus, despite a full schedule of vaccinations," the authors wrote in the paper.

The study appeared in the January 25 issue of the Journal of the American Medical Association.

It was funded by the National Institute of Environmental Health Sciences at the National Institutes of Health, the U.S. Environmental Protection Agency, the Danish Council for Strategic Research and the Danish Environmental Protection Agency.

Co-author Kare Molbak works at the Denmark government vaccine manufacturer Statens Serum Institut.

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Review Date: 
January 28, 2012