Seabird eggs show highest contamination to date
Seabirds' eggs from the San Francisco Bay area have been found to contain the highest levels of toxic chemicals ever traced in wildlife, scientists from the Californian Environmental Protection Agency (EPA) revealed this week.Flame retardant polybrominated diphenyl ethers (PBDEs), which are very similar to neurotoxic chemical polychlorinated biphenyls (PCBs), banned decades ago, was found to be present in the eggs of various Californian seabirds, including the tern.
"Seabirds are useful for monitoring and assessing ecosystem health because they are high on the marine food web, are long-lived and are generally localised nears their breeding and non-breeding sites," explained Dr Jianwen She, a scientist from the Californian EPA's toxic substances control.
"The discovery of unusually high levels of PBDEs suggests that eggs could be valuable tools in monitoring persistent organic pollutants in the environment," she added.
The research showed that PBDEs affected hormonal, neurological and reproductive development and functions in animals. Moreover, large amounts of the chemicals were proven to have a carcinogenic affect.
In addition to the concerns over seabird eggs, the Californian EPA's investigation also showed that breast milk samples from women in the USA contained between 10 and 70 times more PBDEs than samples from women in Europe and Japan.
Scientists are still not sure why this pattern shift is occurring.
By Jane Kettle