Physiological effects of developmental exposure to flame retardant mixture Firemaster 550 or it's components

Firemaster 550 (FM550) is a flame retardant (FR) mixture which has become
one of the most commonly used FRs in household items such as foam-based
furniture and baby products. Because this mixture readily leaches from
products, contamination of the environment and human tissues is
widespread. Prior work by us and others has reported sex-specific
behavioral deficits in rodents and zebrafish following early life
exposure. In an effort to understand the mechanisms by which these
behavioral effects occur, here we explored the effects of its constituents
on behavioral outcomes previously shown to be altered by developmental
FM550 exposure.  The FM550 commercial mixture is composed of two
brominated compounds (BFR) and two organophosphate compounds (OPFRs) at
almost equivalent proportions. Both the BFR and the OPFR components are
differentially metabolized and structurally distinct, but similar to known
neurotoxicants. Here we examined adult Wistar rat offspring socioemotional
behaviors following perinatal exposure (oral, to the Dam) to vehicle, 2000
µg/day FM550, 1000 µg/day BFR or 1000 µg/day OPFR from gestation day 0 to
weaning. Beginning on postnatal day 65 offspring from all groups were
subjected to a series of behavioral tasks including open field, elevated
plus maze, marble burying, social interaction tests, and running
wheel.  Effects were exposure-, sex- and task-specific, with BFR
exposure resulting in the most consistent behavioral deficits. Overall,
exposed females showed more deficits compared to males across all dose
groups and tasks. These findings help elucidate how different classes of
flame retardants, independently and as a mixture, contribute to
sex-specific behavioral effects of exposure.