Researchers found very high levels of the flame retardant PBDE in one of ten samples of butter. The researchers believe the butter wrapper was the source of contamination, and they speculate that Deca-PBDE, which is being phased out of U.S. production, somehow got into the wrapping.
Although the toxicology of such flame retardants is uncertain, Californians have the highest recorded levels in the world of these chemicals in their bodies. Studies suggest the chemicals may be linked to thyroid problems, permanent learning and memory impairment, behavioral changes, hearing loss, delayed puberty onset, decreased sperm count, birth defects, and cancer.
"This would appear to be an isolated incident not representative of the product category, but based on the facts presented, further investigation is warranted," the National Milk Producers Federation said in a statement.
The study can be found at http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1289%2Fehp.1002604#Ahead%20of%20Print%20%28AOP%29.