LOS ANGELES, May 9 (Xinhua) -- Record-high levels of toxic chemicals are threatening peregrine falcons in parts of California, prompting worries about the birds' existence, it was reported Friday.

    State scientists have found that peregrines in Long Beach, Los Angeles and San Francisco contain the highest levels of flame retardants found in any living organism worldwide, the Los Angeles Times reported.

    The findings parallel studies that have detected high concentrations of polybrominated diphenyl ethers, or PBDEs, in human breast milk, particularly in California women.

    The compounds, which mimic thyroid hormones and can damage developing nervous systems, have spread to wildlife and people worldwide, working their way up food webs, The Times reported.

    The concentrations found in California's urban peregrines are similar to those that cause neurological damage in lab mice and rats, resulting in reduced motor skills and altered behavior, said the report.

    Scientists said the peregrines are being contaminated with the industrial chemicals from eating urban pigeons that scavenge on city streets, according to The Times.

    The chemicals are used as flame retardants on electronics and furniture cushions, the newspaper reported. They begin as indoor pollutants, building up in household dust, then migrate outdoors.

    The study was led by Kim Hooper, a scientist with the state Department of Toxic Substances Control's environmental chemistry laboratory.

    Hooper and his colleagues suspected that because household dust contains PBDEs, top predators in big cities would have the worst contamination, so they tested peregrine eggs in 42 locations, including Los Angeles, Long Beach, Newport Beach, Coronado and the San Francisco Bay Area, according to The Times.

    Peregrine falcons were once driven to the edge of extinction by the pesticide DDT.