Michigan’s bald eagles are full of toxic flame retardants.
That’s according to a paper published last month in the Journal of Great Lakes Research. Researchers tested the liver tissues of dead bald eagles collected between 2009 and 2011. Of the 33 eagles tested, 31 tested positive for at least four common types of flame retardants, or polybrominated diphenyl ether (PBDE).
PBDEs were commonly used in manufacturing furniture, carpeting, padding and electronic devices between the 1970s and 2004. After several studies showed that exposure to these chemicals can cause damage to the liver, thyroid and brain, they were banned or voluntarily phased out in Europe and America. Despite the phase out, people the world over, and the environment, remain saturated with flame retardant chemicals.
Humans absorb PBDEs through their skin, via ingestion or inhalation, and exposure has been linked to neurological impairment in children. In birds, exposure has been linked to impaired reproduction, hormone disruption and behavioral and developmental problems. Michigan’s bald eagles have been found to have PBDE concentrations “among the highest…in liver tissues of any wildlife,” likely due to their position as the apex predators in the environment.
This is for the same reason that mercury content is so high in tuna. Tuna are poised near the top of the marine food chain. As smaller fish absorb mercury in the ocean, that mercury is passed on to the creatures that eat them – bioaccumulating in predatory tuna until they are finally caught.
One bald eagle measured 1,538 parts per billion PBDEs in its liver. Compare that to the median American concentration – already among the highest in humans – of about 30 ppb.
As researchers only looked for four specific PBDEs, they note that it is possible bald eagles are saturated with far more. Because of the overall state of chemical dispersal and regulation, Nil Basu, the associate professor who led the study at the University of Michigan, told Environmental Health News that it’s possible the eagles have been exposed to “hundreds of other potentially toxic chemicals.”