Brominated flame retardants as possible endocrine disrupters

Abstract

Brominated flame retardants (BFR) are endocrine disrupters in experimental systems, both in vitro and in vivo. Although BFR effects on thyroid hormones are well confirmed, studies of effects on oestrogen/androgen systems are fewer but today growing in numbers. The effects of BFR on other hormone systems are still unknown. Hormonal effect levels in animals start from ca 1 mg/kg b.w., but there are exceptions: effects on spermatogenesis, suggesting hormonal causes, have been observed at a low dose (60 microg/kg b.w.) of a polybrominated diphenyl ether (PBDE) congener, BDE-99. It could be concluded that hormonal effects are of importance in risk assessment, and in some cases where effects are seen at low levels safety margins may be insufficient. One additional uncertainty is the lack of reliable human data that could be used to support animal BFR observations. In spite of the recent regulation of PBDE production, levels of both PBDE and of other BFR groups are still present in environmental samples. Thus, we have to deal with the possible effects of human BFR exposure for times to come. In order to reduce BFR exposure, the routes of exposure should be carefully examined and ways to reduce levels in major exposure routes considered.

PBDE exposure from food in Ireland: optimising data exploitation in probabilistic exposure modelling

“…In Europe the use of decaBDE is still permitted for all appliances except for electric and electronic equipment (BSEF, 2009), but the scientific discussion about the toxicity of decaBDE is ongoing (Viberg et al, 2003;Van der Ven et al, 2008). Effects of PBDEs in animal models include endocrine disruption, neurodevelopmental and behavioural effects, hepatic abnormalities, and possibly cancer (McDonald, 2002;Birnbaum and Staskal, 2004;Darnerud, 2008). Although little human epidemiology has yet been done, early studies suggest effects on male reproductive hormones (Meeker et al, 2009) and fertility (Akutsu et al, 2008b), thyroid hormone homeostasis (Turyk et al, 2008), cryptorchidism (Main et al, 2007), and lower birth weight and length (Chao et al, 2007).…”

Endocrine disruptive chemicals: mechanisms of action and involvement in metabolic disorders

“…BFRs are a group of industrial chemicals produced in high quantities, mainly used in electric devices, textiles, and cars (for an extensive review see Darnerud 2003Darnerud , 2008. These compounds are present in the environment at increasing levels and will be so for many years to come due to their environmental persistency.…”

Prenatal Exposure to PBDEs and Neurodevelopment

“…Most of these studies have focused on thyroid hormone disruption and a smaller number on disruption of the estrogen/androgen hormone system [reviewed by Darnerud (2008)]. Endocrine disruption during critical developmental periods may result in irreversible effects on differentiating tissue, including the brain (Bigsby et al 1999).…”