Cause For Alarm Over Chemicals - Fire Retardants
Toxic 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.
The chemicals, PBDE's, 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 mattresses, bedding, upholstered furniture, building
materials, televisions, computers and other electronic equipment.
This 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.
But 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
PBDE's used worldwide in 2001 were applied to products in North America.
Scientists who specialize in toxic contaminates say they haven't seen a
chemical build up in human bodies and the environment as quickly as that of
PBDE's in almost half a century. The flame retardants are as potent and long
lasting as PCB's (polychlorinated biphenyls) and DDT- chemicals that began to
accumulate in the environment in the 1950's and were banned in the 1970's. Even
if PBDE's were banned today, they would endure in the environment for decades,
A single, small dose of PBDE's 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 PBDE's performed poorly in maze tests and were hyperactive and slower
to become habituated to a new environment.
"These effects are persistent and worsen with age", said Per Eriksson, a
neurotoxicologist at Uppsala University in Sweden who led the rodent studies.
Only 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 PBDE's that are beginning to approximate those that harm
The 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.
"That 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.
Scientists 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
We're 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.
IMPACT ON INTELLIGENCE
Researchers 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 said.
The 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 studies show.
By far, the highest human exposures are in the United States.
A pregnant Indiana women 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 30's had amounts measuring nearly as much in another study
conducted by the California Department of Toxic Substances Control.
"The levels are rising, and as the levels rise, so should our concern about
health effects," McDonald said.
The 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.
EPA Adminstrator Christine Todd Whitman said in an interview that she is
concerned about the spread of PBDE's but that "we just don't know enough yet" to
take any action, especially because the compounds help protect the public from
Many 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.
"Even 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.
Last month, Assembly-woman Wilma Chan (D-Alameda) introduced a bill that
would restrict the use of PBDE's in products sold in California, beginning in
FIRMS OPPOSE BAN
Representatives of the four companies that manufacture PBDE's say they also
are worried about the buildup in humans and the environment. But the companies
oppose a ban, saying the compounds' benefits to pubic safety are well known and
their risks are uncertain.
We 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 teh Bromine Science and Environmental Forum, and 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.
If 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.
Several dozen flame-retarding compounds other than PBDE's 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 the
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.
Exposure 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
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.
Great Lakes Chemical Corp., based in Indiana, is the only manufacturer of the
type of PBDE's used in furniture and building materials. Albemarle Corp. of
Virginia is the only other U.S. maker of PBDE's.
The 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 PBDE's in their breast milk, tissues and blood as Europeans do.
Of the melange of toxic chemicals that people and wildlife breathe, eat and
drink, only three - lead, mercury and PCB's - are known to harm human health at
levels found in the environment. The new studies provide evidence that PBDE's
may be the fourth.
What disturbs scientists the most about PBDE's are their striking
similarities to PCB's which were widely used as insulating fluids in electrical
transformers until they were banned in the 1970's because they were collecting
in the tissues of people and wildlife.
Like PCB's and the pesticide DDT, PBDE's 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.
"This will be 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
PBDE's 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 second birthday.
Although EPA Administrator Whitman maintains that not enough is known about
the effects of PBDE's to warrant regulating them now, Birnbaum, the EPA's
director of toxicology, said "there is no questions" that the chemicals are
altering thyroid hormones. Altering thyroid hormones during fetal
development "can affect how the brain functions," she said.
Also, Eriksson and other toxicologists say the flame retardants have the same
effects as PCB's on the brains of newborn animals in the same doses.
In 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 PBDE's comparable to the amounts of PCB's that reduce
children's IQ's, toxicologists say.
"These are compounds that have the same properties as PCB's 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 PBDE's.
Reserach teams at Stockholm University and other scientific institutions in
Sweden have led the investigation of the flame retardants. The chemicals,
developed in the 1970's, were first detected in the environment in 1981 in a
river downstream from a textile manufacturing plant southwest of Stockholm.
As demand for flame retardants in electronics and furniture grew in the
1980's, PBDE's began to build up in nature and people, but few scientists
thought to look for them. Then, in the mid-1990's, Swedish scientists checked
women's breast milk and discovered that levels of PBDE's had increased
Stockholm 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 1990's.
PBDE's also are showing up in wildlife worldwide, settling in oceans and
lakes just as PCB's 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.
Ross 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 PBDE's in Great Lakes gulls, trout in Lake Ontario
and seals in San Francisco Bay every two to three years.
Some environmental scientists say the discovery of PBDE's 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 forgot ten lessons learned from the
toxic legacies of the past.
"We knew less about PCB's when they were banned than we know about PBDE's
today," Bergman said. "Those of us who have been around for a while say, 'Didn't
we learn from PCB's?"
(Written by Marla Cone, Copyright © LA Times, Apr 20, 2003, pp. A1 & A30)