Prostate cancer and toxicity from critical use exemptions of methyl bromide: environmental protection helps protect against human health risks

Although ozone-depleting Me bromide was destined for phase-out by 2005, it is still widely applied as a consequence of various critical-use-exemptions and mandatory international regulations aiming to restrict the spread of pests and alien species (e.g. in globalised transport and storage). The withdrawal of Me bromide because of its environmental risk could fortuitously help in the containment of its human toxicity. In this study, the authors conducted a systematic review of the literature, including in vitro toxicology and epidemiological studies of occupational and community exposure to the halogenated hydrocarbon pesticide Me bromide. The main focus was toxic (especially chronic) or carcinogenic effects from the use of Me bromide, on biomonitoring data and reference values. Eligible epidemiological studies were subjected to meta-analysis. Out of the 542 peer reviewed publications between 1990-2011, the authors found only 91 referring to toxicity of Me bromide and 29 using the term “carcinogenic”, “neoplastic” or “mutagenic”. Several studies provide new additional data pertaining to the mechanistic aspects of Me bromide toxicity. Few studies have performed a detailed exposure assessment including biomonitoring. Three evaluated epidemiological studies assessed a possible association between cancer and Me bromide. Overall, exposure to Me bromide is associated with an increased risk of prostate cancer OR, 1.21; 95% CI (0,98-1.49), P ) 0.076. Two epidemiological studies have analysed environmental, non-occupational exposure to Me bromide providing evidence for its health risk to the general public. None of the epidemiological studies addressed its use as a fumigant in freight containers, although recent field and case reports do refer to its toxic effects associated with its use in shipping and storage. The authors concluded that both the epidemiological evidence and toxicological data suggests a possible link between Me bromide exposure and serious health problems, including prostate cancer risk from occupational and community exposure. The environmental risks of Me bromide are not in doubt, but also its health risks, especially for genetically predisposed subjects, should not be underestimated.

Authors: Budnik, Lygia T.; Kloth, Stefan; Velasco-Garrido, Marcial; Baur, Xaver ;Full Source: Environmental Health (London, United Kingdom) 2012, 11, 5 (English) ;