The effectiveness of many of the common vaccines children receive may be seriously reduced by compounds used in the manufacture of grease- and water-resistant coatings found in many consumer goods. A study found that the levels of antibodies provided by the vaccinations were reduced by up to one half in children exposed to perfluorinated compounds (PFCs).

While there are many PFCs, the two that have been most studied are perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonate (PFOS). PFCs are used in the manufacture of pizza boxes, fast food wrappers, microwave popcorn bags, water and stain resistant coatings for clothing, fabric and carpets, and even Teflon.

No microorganisms are known to degrade PFCs and they've been building up in the environment, as well as in the human bloodstream, for over half a century.

People are exposed to these compounds in two different ways: through small amounts present in consumer goods as a contaminant or arising from chemical breakdown of the coating, and from large amounts of PFC waste produced during the manufacture of these goods.

PFCs have been used in increasing amounts since the 1950s. Because of their fluorine content, they're persistent. No microorganisms are known to degrade them and they've been building up in the environment, as well as in the human bloodstream, for over half a century. Some animal studies have suggested that they can cause various health problems, possibly even cancer at very high levels, but little is known about their effect on humans.

The new study points a finger at these compounds suppressing the human immune response. It found roughly a halving of the effectiveness of tetanus and diphtheria vaccines in children at age seven as the PFC content of the children's blood doubled.

The study looked at 656 children born in the Faroe Islands between 1999 and 2001. The Faroe Islands are located in the Norwegian Sea, between Scotland and Iceland. Because the country is an island, fish and seafood consumption is high. Fish and seafood tend to accumulate high levels of various pollutants, and so do the people who eat a diet rich in them. This made the Islanders a seemingly ideal population for a study of the effects of PFCs.

Antibody levels to tetanus and diphtheria were measured at age five, before children normally receive booster shots for these diseases, and at age seven. The level of several different PFCs was measured in the mother's blood before birth, to determine prenatal exposure, and in the children's blood at age five.

The results showed a strong link between higher blood PFCs, mainly PFOA and PFOS, and lower antibody levels. A doubling of PFOS in the mother's blood resulted in a 39% decrease in diphtheria antibody in the child at age five. A doubled PFOA concentration in the child's blood at age 5 meant a decrease in antibodies at age 7 of 36% and 25% to tetanus and diphtheria respectively.

The study can't show that PFCs caused the lowered immune response. Even looking solely at pollutants, a diet high in fish and seafood exposes a person to elevated levels of many pollutants.

Heightened levels of PFCs greatly increased the probability of antibodies falling below a clinically protective level--children not being sufficiently protected by the vaccines.

The study can't show that PFCs caused the lowered immune response. Even looking solely at pollutants, a diet high in fish and seafood exposes a person to elevated levels of many pollutants. What the study can do is point a finger at PFCs as a possible cause.

Other studies suggest that the PFC in the blood comes chiefly from ingesting contaminated food and water. What no one knows is whether this contamination comes mostly from exposure to small amounts of PFCs in consumer goods or the large amount of PFC waste released while producing these goods. And this makes a big difference. It won't do much good to avoid pizza boxes if the PFCs are already in the pizza, though it can't hurt.

In any case, this is unlikely to be the last people will be hearing about PFCs. Even if their production ceased today, they'd still be around in the environment for many decades or longer. And while their production is being phased out in many parts of the world, PFOS production has increased dramatically in China since 2003. Many other PFCs remain in commercial use worldwide.

It's been suggested that people who want to avoid PFCs refrain from buying greasy fast food, avoid stain resistance treatments, choose furniture, carpets and clothing that aren't marked as stain resistant and avoid non-stick cookware. Teflon, while not a PFC, can give off PFCs if heated to 450 degrees Fahrenheit or higher.

An article on the study appears in the Journal of the American Medical Association (JAMA).