Download peregrine falcons in california urban areas are contaminated with

Peregrine Falcons In California's Urban Areas are Contaminated with Toxic Chemicals
By Marla Cone, Los Angeles Times
May 9, 2008
The birds were endangered by DDT in the '70s. Now, scientists have found that falcons
in cities including Los Angeles contain record-high levels of flame retardant.
California's peregrine falcons, once driven to the edge of extinction by the pesticide
DDT, now are contaminated with record-high levels of other toxic chemicals that may
threaten them again.
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 findings parallel studies that have detected high concentrations of the chemicals,
known as 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 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.
Scientists said the peregrines, the fastest and most agile birds, are being contaminated
with the industrial chemicals from eating urban pigeons that scavenge on city streets.
The chemicals are used as flame retardants on electronics and furniture cushions. They
begin as indoor pollutants, building up in household dust, then migrate outdoors, where
they pollute urban environments.
Kim Hooper, a scientist with the state Department of Toxic Substances Control's
environmental chemistry laboratory who led the study, said the PBDE levels in the
peregrines have doubled every 10 years, and might still be increasing.
Hooper and his colleagues suspected that because household dust contains PBDEs, top
predators in big cities would have the worst contamination, so they tested the eggs of
peregrines in 42 locations, including Los Angeles, Long Beach, Newport Beach,
Coronado and the San Francisco Bay Area.
Their hunch was right. The eggs in rural inland and coastal areas had only trace
amounts of PBDEs, but the urban eggs contained up to 52 parts per million, and one
dead chick contained 95 ppm. Scientists consider those concentrations extremely high -substantially higher than nearly any chemical measured in any species worldwide in
recent years.
"We think urban wildlife are sentinels for exposure to indoor pollutants in big cities,"
Hooper said.
Hooper said a PBDE compound called deca is largely responsible for the birds'
contamination. Deca, used in electronics since the 1970s, is produced in large amounts
in the United States -- about 80 million pounds a year.
The peregrine is known for its torpedo-like dives, reaching speeds of up to 200 mph.
Hunting from skyscrapers in large cities as well as from steep cliffs in rural areas, they
inhabit much of North America. They normally shun prey on the ground, choosing to
capture birds mid-flight.
One bird egg, taken from the Port of Long Beach, had the highest level of any egg -- 52
ppm. Other birds with highly contaminated eggs had nested on high-rises in San
Francisco and downtown L.A., including the Union Bank building. Included was a
popular pair that San Francisco residents named George and Gracie.
"We're always concerned when a high level of contaminants is found in a species," said
Alex Pitts, a spokeswoman for the U.S. Fish and Wildlife Service. PBDEs "are showing
up everywhere and they are more concentrated in urban areas, which is challenging for
urban wildlife."
Because the levels have been increasing, "it's very possible they could reach levels in
the food web that could be unsafe for predators such as peregrine falcons," Pitts said.
Janet Linthicum of the Santa Cruz Predatory Bird Research Group, said the high
contaminant levels are "disappointing and disturbing" but she has "no idea whether there
are any effects."
The two dead chicks and 95 unhatchable eggs that were tested came from the Santa
Cruz group's archive and had been collected at nesting sites between 1986 and 2007.
Avian experts say if a bird's nervous system is altered, it might change how it hunts and
raises its young, and perhaps eventually reduce populations.
"Whatever happens to the peregrines, we will be surprised by it, just like we were
surprised when DDT thinned eggshells," Hooper said.
A half century ago, peregrines, bald eagles and brown pelicans were nearly wiped out by
DDT, an insecticide that weakened their egg shells and caused nearly complete
reproductive failure.
Like DDT, the brominated flame retardants are slow to break down in the environment
and build up in animal tissues, reaching high levels in species that top the food web.
PBDE levels in the birds' eggs are about a hundredfold higher than the amounts found in
the breast milk of California women, who have among the highest concentrations of
women tested worldwide, the scientists said.
Children are five to 10 times more contaminated than adults because they are exposed
to more dust from playing on floors.
The recovery of the peregrine, known as the bird of kings because of its prized role in
falconry, has long been hailed as one of the nation's greatest ecological success stories.
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In the 1970s, its numbers in North America plummeted to about 300 breeding pairs,
including only two pairs in California. But its populations have been growing since DDT
was banned in the United States in 1972, and the bird was removed from the nation's
endangered species list in 1999. About 3,000 pairs inhabit North America, including
about 200 pairs in California.
California recently banned two PBDEs, known as penta and octa, because they were
accumulating in human breast milk, but deca is unregulated in the state. It is banned or
being phased out only in Maine, Washington state and Sweden. However, some large
manufacturers of computers and other electronics have voluntarily stopped using deca.
Until recently, deca wasn't detected much in the environment. In this study, the state
scientists are reporting that it contaminates the birds by breaking down into the toxic
compounds that were banned.
"What's striking is that the peregrines are contaminated with the highest brominated
ones, the deca, which had not been found previously at such high levels," Hooper said.
"It may be time to look for green alternatives for deca."
Assemblyman Mark Leno (D-San Francisco), has introduced a bill that would ban all
brominated and chlorinated flame retardants. Chemical industry representatives oppose
the bill, saying deca is important to protect people from fires in electronic equipment and
that there is little evidence that it is responsible for the contamination.
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