Toxicity of Polybrominated Diphenyl Ethers and Other Flame Retardants to Wildlife
Flame retardants are a class of commonly used household and industrial products. Because of widespread use, there is concern that their presence in the environment can potentially pose a hazard and risk to wildlife.
The Challenge: Polybrominated diphenyl ether flame retardants (PBDEs) are contaminants that bioaccumulate and biomagnify in aquatic and terrestrial food webs. Unlike many contemporary pollutants, these flame retardants have increased in the environment over the past 30 years. Studies in Chesapeake and Delaware Bays have documented concentrations of nearly 1 μg/g wet weight of PBDEs in osprey eggs, and even greater levels in peregrine falcon eggs. Limited information is available on the toxicity thresholds of these compounds and new organophosphate flame retardants in wildlife.
The Science: We are determining the toxicity of PBDE flame retardants in various bird embryos (chicken, mallard, American kestrel, black-crowned night-heron and common tern) over a wide range of environmentally realistic doses. Measurements include embryonic survival, pipping and hatching success, and various biochemical, endocrinological, and immunological endpoints. In addition, studies also examined the toxicity of various organophosphate flame retardants in adult kestrels. The goal of these studies is to establish adverse-effect thresholds that can be used to interpret concentrations in free-ranging bird eggs collected from potentially polluted sites.
The Future: The penta-BDE formulation delayed hatching, and also decreased pipping and hatching success at 20 μg/g egg in kestrels, but had no effect on survival endpoints. Evidence of genotoxicity and oxidative stress was detected in kestrels and terns. Six congeners or co-eluting pairs of congeners were detected in treated eggs that were not found in the dosing solution suggesting metabolism in the developing embryo. Based on PBDE uptake rate in kestrel embryos, the lowest-observed-adverse-effect-level on pipping and hatching success was 1.8 μg total PBDE/g egg wet weight, which approaches concentrations detected in eggs of free-ranging birds. Studies with organophosphate flame retardants suggest that they are rapidly metabolized, and seemingly of minimal risk to predatory birds.
Below are publications associated with this project.
In ovo exposure to brominated flame retardants Part I: Assessment of effects of TBBPA-BDBPE on survival, morphometric and physiological endpoints in zebra finches
In ovo exposure to brominated flame retardants Part II: Assessment of effects of TBBPA-BDBPE and BTBPE on hatching success, morphometric and physiological endpoints in American kestrels
Sex‐specific responses in neuroanatomy of hatchling American kestrels in response to embryonic exposure to the flame retardants bis(2‐ethylhexyl)‐2,3,4,5‐tetrabromophthalate and 2‐ethylhexyl‐2,3,4,5‐tetrabromobenzoate
Female hatchling American kestrels have a larger hippocampus than males: A link with sexual size dimorphism?
Investigating endocrine and physiological parameters of captive American kestrels exposed by diet to selected organophosphate flame retardants
Comparative embryotoxicity of a pentabrominated diphenyl ether mixture to common terns (Sterna hirundo) and American kestrels (Falco sparverius)
Absorption and biotransformation of polybrominated diphenyl ethers DE-71 and DE-79 in chicken (Gallus gallus), mallard (Anas platyrhynchos), American kestrel (Falco sparverius) and black-crowned night-heron (Nycticorax nycticorax) eggs
Toxicity of polybrominated diphenyl ethers (de-71) in chicken (Gallus gallus), mallard (Anas platyrhynchos), and American kestrel (Falco sparverius) embryos and hatchlings
Below are partners associated with this project.
Flame retardants are a class of commonly used household and industrial products. Because of widespread use, there is concern that their presence in the environment can potentially pose a hazard and risk to wildlife.
The Challenge: Polybrominated diphenyl ether flame retardants (PBDEs) are contaminants that bioaccumulate and biomagnify in aquatic and terrestrial food webs. Unlike many contemporary pollutants, these flame retardants have increased in the environment over the past 30 years. Studies in Chesapeake and Delaware Bays have documented concentrations of nearly 1 μg/g wet weight of PBDEs in osprey eggs, and even greater levels in peregrine falcon eggs. Limited information is available on the toxicity thresholds of these compounds and new organophosphate flame retardants in wildlife.
The Science: We are determining the toxicity of PBDE flame retardants in various bird embryos (chicken, mallard, American kestrel, black-crowned night-heron and common tern) over a wide range of environmentally realistic doses. Measurements include embryonic survival, pipping and hatching success, and various biochemical, endocrinological, and immunological endpoints. In addition, studies also examined the toxicity of various organophosphate flame retardants in adult kestrels. The goal of these studies is to establish adverse-effect thresholds that can be used to interpret concentrations in free-ranging bird eggs collected from potentially polluted sites.
The Future: The penta-BDE formulation delayed hatching, and also decreased pipping and hatching success at 20 μg/g egg in kestrels, but had no effect on survival endpoints. Evidence of genotoxicity and oxidative stress was detected in kestrels and terns. Six congeners or co-eluting pairs of congeners were detected in treated eggs that were not found in the dosing solution suggesting metabolism in the developing embryo. Based on PBDE uptake rate in kestrel embryos, the lowest-observed-adverse-effect-level on pipping and hatching success was 1.8 μg total PBDE/g egg wet weight, which approaches concentrations detected in eggs of free-ranging birds. Studies with organophosphate flame retardants suggest that they are rapidly metabolized, and seemingly of minimal risk to predatory birds.
Below are publications associated with this project.
In ovo exposure to brominated flame retardants Part I: Assessment of effects of TBBPA-BDBPE on survival, morphometric and physiological endpoints in zebra finches
In ovo exposure to brominated flame retardants Part II: Assessment of effects of TBBPA-BDBPE and BTBPE on hatching success, morphometric and physiological endpoints in American kestrels
Sex‐specific responses in neuroanatomy of hatchling American kestrels in response to embryonic exposure to the flame retardants bis(2‐ethylhexyl)‐2,3,4,5‐tetrabromophthalate and 2‐ethylhexyl‐2,3,4,5‐tetrabromobenzoate
Female hatchling American kestrels have a larger hippocampus than males: A link with sexual size dimorphism?
Investigating endocrine and physiological parameters of captive American kestrels exposed by diet to selected organophosphate flame retardants
Comparative embryotoxicity of a pentabrominated diphenyl ether mixture to common terns (Sterna hirundo) and American kestrels (Falco sparverius)
Absorption and biotransformation of polybrominated diphenyl ethers DE-71 and DE-79 in chicken (Gallus gallus), mallard (Anas platyrhynchos), American kestrel (Falco sparverius) and black-crowned night-heron (Nycticorax nycticorax) eggs
Toxicity of polybrominated diphenyl ethers (de-71) in chicken (Gallus gallus), mallard (Anas platyrhynchos), and American kestrel (Falco sparverius) embryos and hatchlings
Below are partners associated with this project.