Natural compounds akin to synthetic flame retardants wend their way up marine food chains and accumulate in whale blubber, researchers have found. It's the first time that scientists have used a new radiocarbon-dating method to determine whether potentially troublesome chemicals in the environment are of natural or synthetic origin.
The oceans contain thousands of naturally occurring organic compounds that incorporate the halogen atoms chlorine and bromine. Used by organisms for such purposes as self-defense, some of these halogenated chemicals have become valuable drugs, while others are harmful to people.
Human activities generate halogenated compounds that can be similar or identical to those made in nature. For example, polybrominated diphenyl ethers (PBDEs) are human-made flame retardants that some scientists suspect have negative health effects (SN: 10/25/03, p. 266: http://sciencenews.org/articles/20031025/bob10.asp). Certain sponges harbor similar but natural ha