Mammalian Toxicity of Organic Compounds of Bromine and Iodine

Human beings are exposed to an increasing number and increasing amounts of organo-bromine and organochlorine compounds, both of man-made and natural origin. The commercial products of this nature present at highest levels in the general environment include alkyl halides (in particular, methyl bromide), aryl halides and polybrominated diphenyl ethers, all of which exert well-documented toxic effects on mammalian cells. The major systems affected include the points of contact with the environment (i.e., the pulmonary and gastrointestinal tracts and the skin), the central nervous system and the liver. In addition, some of these substances disrupt the hormonal status with respect to thyroid hormones and estrogens. If not easily predictable at present, many of these forms of toxicity are not surprising in light of the reactivity, hydrophobicity, and/or structural properties of the compounds in question.