20 April 2003
for Alarm Over Chemicals
* Levels of common fire retardants in humans are rising rapidly,
especially in the U.S. Animal tests show effects on the brain.
Marla Cone, Los Angeles Times Staff Writer
chemicals used as flame retardants are rapidly building up in the
bodies of people and wildlife around the world, approaching levels
in American women and their babies that could harm developing brains,
new research shows.
chemicals, PBDEs, or polybrominated
diphenyl ethers, are used to reduce the spread of fire in an
array of plastic and foam products in homes and offices, including
upholstered furniture, building materials, televisions, computers
and other electronic equipment.
year, the European Union banned the two PBDE compounds that have
been shown to accumulate in human bodies. Some European industries
had already begun to phase out the chemicals, and levels in the
breast milk of European women have begun to decline.
in the United States, no action to regulate the flame retardants
has been taken, and their use continues to rise. About half of the
135 million pounds of PBDEs used worldwide in 2001 were applied
to products in North America.
who specialize in toxic contaminants say they haven't seen a chemical
build up in human bodies and the environment as quickly as that
of PBDEs in almost half a century. The flame retardants are as potent
and long-lasting as PCBs (polychlorinated biphenyls) and DDT-- chemicals
that began to accumulate in the environment in the 1950s and were
banned in the 1970s. Even if PBDEs were banned today, they would
endure in the environment for decades, scientists say.
single, small dose of PBDEs fed to newborn laboratory mice and rats
disrupts their brain development, altering their learning ability,
memory, behavior and hearing, according to three studies, two conducted
in Europe and one at the U.S. Environmental Protection Agency. Mice
fed less than 1 part per million of PBDEs performed poorly in maze
tests and were hyperactive and slower to become habituated to new
about these studies
effects are persistent and worsen with age," said Per Eriksson,
a neurotoxicologist at Uppsala University in Sweden who led the
a few hundred people in the U.S. have been tested so far. But studies
completed in the last few months show that some American women and
their babies are carrying levels of PBDEs that are beginning to
approximate those that harm newborn rodents.
brains of newborn mice are altered when their bodies contain concentrations
that are 10 to 100 times higher than levels already seen in some
people in the United States today.
is not a comfortable margin of exposure," said Linda Birnbaum,
director of experimental toxicology at the EPA's National Health
and Environmental Effects Research Laboratory. Because concentrations
in Americans are doubling every few years, it won't take long to
close the gap.
have not yet determined how the flame retardants are getting into
human beings. Some suspect that dust in homes and offices containing
foam from old furniture cushions is the primary source; others suspect
it comes mainly from consumption of fish caught in contaminated
waters. The uncertainty complicates the task of figuring out ways
to tell people how they can reduce their exposure.
adding them to consumer products, so they're in every home, every
office, every car, every bus, every plane," said Tom McDonald,
a toxicologist with the California Environmental Protection Agency's
Office of Environmental Health Hazard Assessment.
say the effects on children are likely to be subtle -- not mental
retardation or disability, but measurable changes in a child's intelligence,
memory, hyperactivity and hearing. "We're concerned about learning
and memory and some behavioral effects and hearing loss," Birnbaum
flame retardants, which pass through the placenta and are readily
absorbed by a fetus, are doubling in concentration every two to
five years in people and wildlife throughout North America, several
far, the highest human exposures are in the United States.
pregnant Indiana woman had the largest individual concentration
found so far -- 580 parts per billion -- and her baby carried nearly
as much at birth, according to an Indiana University study published
last month. A San Francisco Bay Area woman in her 30s had amounts
measuring nearly as much in another new study conducted by the California
Department of Toxic Substances Control.
levels are rising, and as the levels rise, so should our concern
about health effects," McDonald said.
federal EPA, which has jurisdiction over the chemicals, has made
no move to regulate them. The agency has begun a risk assessment
of the compounds, which is expected to be completed next year.
Administrator Christine Todd Whitman said in an interview that she
is concerned about the spread of PBDEs, but that "we just don't
know enough yet" to take any action, especially because the
compounds help protect the public from fires.
scientists in the United States, Canada and Europe disagree. Two
Cal/EPA scientists, writing in a scientific journal, have recommended
a phase-out of the chemicals.
in the absence of further studies, it seems clear that less toxic
alternatives to the persistent PBDE flame retardants are desirable,"
wrote McDonald and Cal/EPA scientist Kim Hooper.
month, Assemblywoman Wilma Chan (D-Alameda) introduced a bill that
would restrict the use of PBDEs in products sold in California,
beginning in 2006.
of the four companies that manufacture PBDEs say they also are worried
about the buildup in humans and the environment. But the companies
oppose a ban, saying the compounds' benefits to public safety are
well known and their risks are uncertain.
are concerned about the findings, and we want to get to the bottom
of this as much as the regulators and scientists do," said
Lawrie McLaren, program director for the Bromine Science and Environmental
Forum, an industry group. "At the same time, you have a product
with a proven benefit, as far as saving people's lives, so one has
to be very careful."
a fire occurs, products treated with flame-retarding chemicals provide
as much as 15 times as much escape time as untreated products, according
to the industry group. In Great Britain, a government report estimated
that flame retardants on furniture saved about 1,800 lives there
in a 10-year period.
dozen flame-retarding compounds other than PBDEs exist. Some of
them do not accumulate in tissues and pose less risk. Electronics
manufacturers already are switching to them or are altering their
plastics so that retardants are unnecessary. But the chemical companies
say there are drawbacks in some applications, including higher costs,
less effective fire retardancy and reduced durability of furniture.
is probably highest in North America because it is the only place
still using the form of PBDE most likely to accumulate in humans
and the environment. That compound, penta-BDE, is banned in Europe
but is used in the polyurethane foam of furniture and building materials
in the United States. Much less is known about any health effects
of PBDE compounds that are applied to computers and electronics
equipment and whether they accumulate in bodies.
Lakes Chemical Corp., based in Indiana, is the only manufacturer
of the type of PBDEs used in furniture and building materials. Albemarle
Corp. of Virginia is the only other U.S. maker of PBDEs.
exposure levels of tested Americans vary widely -- some people carry
concentrations as much as 100 times as high as others -- and they
follow no obvious geographic pattern. On average, however, Americans
carry 10 to 70 times as much PBDEs in their breast milk, tissues
and blood as Europeans do.
the melange of toxic chemicals that people and wildlife breathe,
eat and drink, only three -- lead, mercury and PCBs -- are known
to harm human health at levels found in the environment. The new
studies provide evidence that PBDEs may be the fourth.
disturbs scientists the most about PBDEs are their striking similarities
to PCBs, which were widely used as insulating fluids in electrical
transformers until they were banned in the 1970s because they were
collecting in the tissues of people and wildlife.
PCBs and the pesticide DDT, PBDEs are slow to break down, persisting
in the environment and accumulating in human and animal fat. PBDE
concentrations increase as the chemicals move up through the food
web, peaking in top predators such as whales, dolphins, birds of
prey and humans.
will be a social experiment we'll be following for the next 20 years.
It is not going away," said Hooper, a scientist at Cal/EPA's
Hazardous Materials Laboratory.
mimic thyroid hormones, which regulate the growth of a baby's neurological
system. Because of that, if exposure comes during a critical phase
of brain growth, it can alter how the brain develops, said Eriksson,
the Swedish toxicologist. "There is a window of development
when these compounds cause effects," Eriksson said. In humans,
that period lasts from the third trimester of pregnancy to a child's
EPA Administrator Whitman maintains that not enough is known about
the effects of PBDEs to warrant regulating them now, Birnbaum, the
EPA's director of toxicology, said "there is no question"
that the chemicals are altering thyroid hormones. Altering thyroid
hormones during fetal development "can affect how the brain
functions," she said.
Eriksson and other toxicologists say the flame retardants have the
same effects as PCBs on the brains of newborn animals in the same
several studies, children born to women who ate large amounts of
PCB-contaminated fish have been found to have reduced intelligence.
Some women are carrying amounts of PBDEs comparable to the amounts
of PCBs that reduce children's IQs, toxicologists say.
are compounds that have the same properties as PCBs and DDT, and
it's just a matter of concentration before we have a toxic effect,"
said Aake Bergman, Stockholm University's chief of environmental
chemistry and one of the world's leading scientists regarding PBDEs.
teams at Stockholm University and other scientific institutions
in Sweden have led the investigation of the flame retardants. The
chemicals, developed in the 1970s, were first detected in the environment
in 1981 in a river downstream from a textile manufacturing plant
southwest of Stockholm.
demand for flame retardants in electronics and furniture grew in
the 1980s, PBDEs began to build up in nature and people, but few
scientists thought to look for them. Then, in the mid-1990s, Swedish
scientists checked women's breast milk and discovered that levels
of PBDEs had increased sixtyfold.
University researcher Daiva Meironyte-Guvenius said the growth in
breast milk "was very scary. The reaction here in Sweden was
very powerful." Facing public and political pressure, companies
in Europe began to voluntarily phase out use of the most persistent
flame retardants in the late 1990s.
also are showing up in wildlife worldwide, settling in oceans and
lakes just as PCBs and DDT did. Even polar bears near the North
Pole and sperm whales feeding in deep ocean waters are contaminated
with them. The effects on wildlife are unknown.
Norstrom of the Canadian Wildlife Service, who has studied contaminants
in wildlife for 30 years, said he was "flabbergasted"
by the rapid buildup in North America: a doubling of PBDEs in Great
Lakes gulls, trout in Lake Ontario and seals in San Francisco Bay
every two to three years.
environmental scientists say the discovery of PBDEs near the North
Pole proves their global spread, and that this should be an impetus
for U.S. regulators to take precautionary measures as soon as possible.
Many say they are dismayed that industry and society have forgotten
lessons learned from the toxic legacies of the past.
knew less about PCBs when they were banned than we know about PBDEs
today," Bergman said. "Those of us who have been around
for a while say, 'Didn't we learn from PCBs?' "