Perfluorinated compounds (PFCs) [see http://en.wikipedia.org/wiki/Perfluorinated_compounds] are widely used in a variety of manufactured products, such as non-stick cookware (e.g., teflon), waterproof clothing (e.g., Scotchgard), and fast-food packaging (e.g., microwave popcorn bags). PFC's can be transferred to children prenatally (via the mother) and postnatally from exposure in the environment (e.g., food, clothing). Recent experiments have strongly indicated that PFC's can damage the immune system and, when injected into pregnant mice (for example), PFC's resulted in toxicity to the pups’ immune system. The offspring were unable to produce the necessary antibodies toward a standard foreign protein. This immunotoxicity effect was observed to occur at blood PFC concentrations similar to those common in the U.S. and other western populations. [See http://www.ncbi.nlm.nih.gov/pubmed/22109712.] As prior posts have noted, animal studies are not human studies, but are often persuasive evidence of a potential for harm, especially when there is a commonality of mammalian bodily systems. [See http://www.time.com/time/health/article/0,8599,1815241,00.html.]
Researchers thus examined whether damage to the immune system may occur in children exposed to PFC's. As an expression of overall immune function, they measured the serum concentration of antibodies against tetanus and diphtheria; all children had been vaccinated against these diseases four times by age 5 years. A total of 656 children were enrolled in the study.
The PFC exposure was measured in blood samples taken at two points in time – from the pregnant mother at the last examination before birth, and from the child at age 5 years of age. Blood samples were obtained from a total of 587 of the children. Five different PFC compounds were measured and were found to be present in all blood samples. The child’s antibodies were measured just before the last vaccination and again two years later at age 7 years.
The PFC content in the blood sample from the mother showed an inverse relationship with the child's level of antibodies at age 5, before the fourth vaccination. Thus, the child's prenatal PFC exposure was associated with a decreased ability to produce antibodies later in life.
The most distinct effect was found in the 7-year-old children. The overall negative effect corresponded to a halving of the antibody level when the PFC exposure doubled. The authors note that this steep negative association suggests an influence that is stronger than the effect caused by dioxin exposure. Only a few medical conditions, such as some rare hereditary diseases, radiation and certain types of cancer drugs, are otherwise known to interfere strongly with children’s ability to respond to vaccinations.
Thus, children so exposed had a markedly reduced immunological ability to contend with disease.
The study can be found at http://jama.ama-assn.org/content/307/4/391.short.
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