Breast Milk Now Plagued with Poisons

from NYT Magazine
January 9, 2005
FIRST PERSON

Toxic Breast Milk?
By FLORENCE WILLIAMS

If human breast milk came stamped with an ingredients label, it might read
something like this: 4 percent fat, vitamins A, C, E and K, lactose,
essential minerals, growth hormones, proteins, enzymes and antibodies. In a
healthy woman, it contains 100 percent of virtually everything a baby needs
to survive, plus a solid hedge of extras to help ward off a lifetime of
diseases like diabetes and cancer. Breast milk helps disarm salmonella and
E. coli. Its unique recipe of fatty acids boosts brain growth and results in
babies with higher I.Q.'s than their formula-slurping counterparts. Nursing
babies suffer from fewer infections, hospitalizations and cases of sudden
infant death syndrome. For the mother, too, breast-feeding and its delicate
plumbing of hormones afford protection against breast and ovarian cancers
and stress. Despite exhaustion, the in-laws and dirty laundry, every time we
nurse our babies, the love hormone oxytocin courses out of our pituitaries
like a warm bath. Human milk is like ice cream, Valium and Ecstasy all
wrapped up in two pretty packages.

But read down the label, and the fine print, at least for some women,
sounds considerably less appetizing: DDT (the banned but stubbornly
persistent pesticide famous for nearly wiping out the bald eagle), PCB's,
dioxin, trichloroethylene, perchlorate, mercury, lead, benzene, arsenic.
When we nurse our babies, we feed them not only the fats, sugars and
proteins that fire their immune systems, metabolisms and cerebral synapses.
We also feed them, albeit in minuscule amounts, paint thinners, dry-cleaning
fluids, wood preservatives, toilet deodorizers, cosmetic additives, gasoline
byproducts, rocket fuel, termite poisons, fungicides and flame retardants.

If, as Cicero said, your face tells the story of your mind, your breast
milk tells the decades-old story of your diet, your neighborhood and,
increasingly, your household decor. Your old shag-carpet padding? It's
there. That cool blue paint in your pantry? There. The chemical cloud your
landlord used to kill cockroaches? There. Ditto, the mercury in last week's
sushi, the benzene from your gas station, the preservative parabens from
your face cream, the chromium from your neighborhood smokestack. One
property of breast milk is that its high-fat and -protein content attracts
heavy metals and other contaminants. Most of these chemicals are found in
microscopic amounts, but if human milk were sold at the local Piggly Wiggly,
some stock would exceed federal food-safety levels for DDT residues and
PCB's.

Some of the chemicals I'm mainlining to my 1-year-old daughter will stay in
her body long enough for her to pass them on to her own offspring. PCB's,
for example, can remain in human tissue for decades. On a body-weight basis,
the dietary doses my baby gets are much higher than the doses I get. This is
not only because she is smaller, but also because her food -- my milk --
contains more concentrated contaminants than my food. It's the law of the
food chain, and it's called biomagnification.

To refresh that lesson from seventh grade, here's how it works: Animals at
the top of the food chain receive the concentrated energy and persistent
chemicals of all the biota underneath them. Each member up the food chain
takes in exponentially more fat-loving toxins than its counterpart below.
This is why a slab of shark contains more mercury than its weight in
plankton. Ocean food chains are longer than terrestrial ones, so people who
eat many marine carnivores carry higher body concentrations of some
chemicals than the vegan at your local salad bar. When it comes to these
fat-soluble toxins, the Inuit are among the most contaminated populations on
earth, even though they live in the remote Arctic. But don't picture Eskimo
Woman in sealskin on the top of the food chain. Picture her suckling baby.

For a mother and child, nursing is perhaps the most intimate of acts.
Evolutionary biologists call it matrotropy: eating one's mother. My daughter
is not only physically attached to me; she is taking from me all that I can
give her. Each time I lift my shirt, she pants and flaps her arms and legs
as if it were Christmas. Then she settles in, both of us wholly reassured
that this is the best, safest and most satisfying food she could eat. I
nurse because, like many women, this is what I've been told by contemporary
pregnancy books and my pediatrician. I want to give her the best possible
start in an uncertain world.

I take this responsibility seriously, as most of us do; for her sake, I
don't drink much alcohol or caffeine. I avoid spicy foods, strawberries and
cruciferous vegetables, which are believed to cause gas in babies. I take my
vitamins to ensure that I have enough calcium and iron. I don't smoke. I'm
aware of concerns about pesticides and heavy metals, and I try to take
precautions. Since I have been pregnant with or nursing two children for
almost four years, I have been buying mostly organic food. Several years ago
we installed a three-stage reverse-osmosis filter on our tap water and ice
maker. I live in a leafy, scenic town in the Rocky Mountains far from brown
clouds and belching diesel freeways.

So it was with increasing discomfort that I scanned recent headlines about
pervasive toxic chemicals, the ones you can't easily avoid. There were
articles about elevated mercury levels in women of child-bearing age,
federal actions against the makers of Teflon and flame retardants
accumulating in breast milk. This last one especially frightened me. Not
only was nature's purest food tainted by chemicals, but the act of
breast-feeding itself, an act of love and nurture, was also now marred by
fear. Had I been wrong to be so smug about the superiority of
breast-feeding? Should I switch to formula, which contains plant-based fats
and therefore lower levels of some contaminants (although it may contain
higher levels of others, like aluminum and manganese, as well as the
pathogens and pesticides found in tap water)? I learned that in general,
older women have stored up more toxins than younger ones. Scientists believe
that mothers siphon off to their baby a significant amount of their lifelong
store of chemicals in the course of breast-feeding. Nursing a baby, it turns
out, is the ultimate detox diet. I'm 37. What toxins have I passed on to my
son and daughter?

To find out, I sent my breast milk off to be tested for certain flame
retardants called PBDE's, reputed in some press reports to be ''the next
PCB,'' a class of industrial chemicals banned in the late 70's. I knew some
PBDE's would turn up; they are found in virtually every animal and human
tested so far. The milk of American women has the highest levels in the
world, although still mostly lower (we think and hope) than levels at which
health effects might be seen in us or our children. What these levels tell
us is that our world is full of unhappy and improbable surprises, like the
fact that the plastic in our computers and TV's somehow ends up inside us.
Our collective levels tell us that the chemicals are increasing over time,
that someone should be paying attention and that it would be helpful to know
what havoc may be wreaked in our cells if present trends continue.

Waiting for results over the next two months, I learned more about
chemicals in my everyday life. I began eyeing my degrading foam mouse pad:
was I ingesting it? I read the ingredients label on my sunscreen. I noticed
the little white pesticide-notification flags on my neighbors' lawns. I
watched my 3-year-old son. Was he meeting his development targets? How was
his attention span? I recognized that in its incremental way, alarm over
toxic contamination creates a perfect storm for the overanxious parent. Now
in addition to worrying about the right schools, dirty bombs and car-seat
recalls, we get to wonder if our mattresses are emitting developmental
neurotoxins.

During this time, one thing became clear to me: we live in a
flame-retardant nation. The reason is polyurethane. Originally used by the
German Army in World War II, by the mid-50's the polymer was transforming
everything from refrigeration insulation to upholstered foam furniture to
car bumpers. It was an industrial miracle: cheap, soft and malleable. As one
industry Web site puts it, ''Today, polyurethanes can be found in virtually
everything we touch -- our desks, chairs, cars, clothes, footwear,
appliances, beds, the insulation in our walls, roof and moldings on our
homes.''

It has just one problem: it's highly flammable. Responding to strong
consumer-protection laws dating from the 70's, manufacturers increasingly
treated household foam and plastics with brominated flame retardants. The
National Association of State Fire Marshals says that such fire retardants
have saved hundred of lives from house fires. They also help prevent the
release of combustion byproducts like dioxin, a known human carcinogen.
PBDE's reflect a wholly modern conundrum: they are one toxic solution most
of us didn't know existed to a toxic problem most of us didn't know we had.

For the flame retardant to work, foams, plastics and fabrics are mixed
with, or coated in, PBDE's, polybrominated diphenylethers, but in such a way
that the chemical is not molecularly bound to anything. It appears to
migrate out of its product and attach to household dust. A class of
so-called organic compounds, PBDE's have as one of their signature
properties fat-solubility. Hence their unwelcome appearance in our breast
milk. They may remain in humans for several months to at least several
years. Semi-volatile in the environment, certain PBDE's have lately been
found in soil sediments; in chicken, pork, sausage and dairy products; in
sewage sludge and crop fertilizer; in fresh and saltwater fish; in wild
birds; on computer and desk surfaces; in clothes-dryer lint; on the insides
of residential windows; and in human fetal liver tissue.

Persistent toxins were first discovered in breast milk in 1951, when black
mothers in Washington were tested for the pesticide DDT. In 1966, a Swedish
researcher thought to test his wife's breast milk for PCB's, or
polychlorinated biphenyls, after he discovered them in the tissue of a dead
eagle. Five years later, Sweden banned PCB's, with the United States
following a few years later. But because of those chemicals' widespread use
and persistence, they are still the highest-concentration toxins in breast
milk, even in mothers born after the 1978 ban. Most scientists maintain that
prenatal exposure to PCB's -- considered by the Environmental Protection
Agency to be a probable human carcinogen -- can do real damage. Researchers
in the Great Lakes region, the Arctic and the Netherlands found that babies
born to mothers with mid- to upper-range background levels of PCB
contamination (probably because of diets rich in contaminated fish and
animal products) have delayed learning capabilities, lower I.Q.'s and
reduced immunities against infections. The longitudinal studies on which
these findings were based showed that some problems persisted at least into
early adolescence.

The message from these studies about breast-feeding, however, was not what
you might expect. Although the children who were breast-fed had higher PCB
levels than children who were exposed only in utero, they consistently
performed better than those who drank formula. When researchers controlled
for socioeconomic factors, the differences were more subtle but still there.
In other words, breast milk appears to be at least partly protective against
the effects of toxic chemicals. In fact, the World Health Organization and
other groups continue to recommend breast-feeding for all women. At first
this sounds reassuring, until you wonder how much better the breast milk
would be without the companion chemicals. We'll never know, since an
uncontaminated control group doesn't exist.

Swedish researchers first discovered the PBDE flame retardants in pike in
1981. Like PCB's, they concentrated in fat and stuck around. But unlike
PCB's, whose levels were gradually declining worldwide, the flame-retardant
levels were rising. The Swedes decided to look for the chemicals in stored
human milk samples, and what they found rocked the scientific community:
from the early 70's, when they first appeared commercially, to 1998, levels
of PBDE's in breast milk were doubling every five years, a rate unmatched by
any known chemical in the last 25 years.

''No one had ever heard of them -- we thought it was just a European
problem,'' said Kim Hooper, a specialist with the California Department of
Toxic Substances Control. ''So our lab looked in San Francisco Bay seal
blubber, and found a 100-fold increase over 10 years.'' When European
scientists first saw the test results of American women, they thought there
must be a mistake. Our levels were 10 to 100 times higher than those of
women in Europe and Japan.

So far, little is known about the health effects of PBDE's in humans. It's
difficult to experiment with human subjects, and so to estimate toxicity
scientists look to laboratory animals. What they have found is that in rats,
exposure to PBDE's has resulted in damage to the thyroid and its ability to
orchestrate proper brain development, although the exact mechanism remains
unclear. We know that the offspring of exposed rats suffer reduced motor
function, and that some develop tumors at high doses of one type of PBDE.
Several recent animal studies indicate that PCB's and PBDE's may act in
unison to block protein receptors and affect thyroid and endocrine
functioning.

Such observations can be useful in helping us determine toxic chains of
events but not in predicting at what dose the bad effects occur in humans.
And, as Paracelsus put it, the dose makes the poison. The dose required to
harm a developing fetus or small baby is likely to be much lower than to
harm an adult.

''No one at this time knows at what levels nursing is not the best approach
and in fact becomes harmful to babies,'' said Arnold Schecter, at the
University of Texas School of Public Health, the researcher to whom I sent
my samples. ''But such levels must exist.''

Aake Bergman, head of the department of environmental chemistry at
Stockholm University, whose data was instrumental in influencing the
European Union to ban two formulations of PBDE's, said: ''I hope I never
will be able to tell you about effects in humans. We will so totally have
failed if we see effects in humans.''

hen Congress ordered the banning of PCB's in 1976, it also passed the Toxic
Substances Control Act, which authorized the U.S. Environmental Protection
Agency to approve and regulate new chemicals. Approximately 58,000 existing
chemicals were grandfathered in, no questions asked, including PBDE's.
Today, about 15,000 chemicals are used commercially in the United States.
Under the law, manufacturers are required to submit any available
information on the health and safety of new chemicals, and the Environmental
Protection Agency has 90 days to assess it. Manufacturers are also required
to submit available toxicity information as it becomes available on older
substances. But with 2,000 new chemicals proposed every year and limited
data to review, the agency is seriously behind the curve. Of chemicals used
by children and families in consumer products, only about 25 percent have
registered complete toxicity data. In nearly 30 years, the E.P.A. has
required manufacturers to test about 1,500 chemicals, or 10 percent of the
total, and flat-out rejected only a handful of chemicals.

''We don't like to see a chemical building up in the tissues of people,''
said Charlie Auer, director of the E.P.A.'s Office of Pollution Prevention
and Toxics. With PBDE's, he said, ''there certainly is a basis for some
level of concern, but we don't have enough information.'' Still, in 2003 his
office reached an agreement with the biggest manufacturer of PBDE's, Great
Lakes Chemical Corporation, to stop producing two of three formulations by
the end of 2004. Existing stocks of those two forms of the chemical will be
used and eliminated ''over time,'' he said.

And so I do what any mother would: I try to gain a sense of control. Not
entirely happy about the exposed foam in my husband's old pick-up, I cover
the rips with duct tape. I retire my son's adorable airplane-print foam
chair to the garage. I even replace his questionable polystyrene beanbag
with one made out of organic buckwheat hulls. But there's not much I can do
about the television sets, computers, printers, coffee makers, carpets, roof
insulation and the rest of it short of moving my family into a tree and
sleeping on a horse-hair mattress.

To get a reality check, I call David Ropeik, a former environmental
journalist now with the Harvard Center for Risk Analysis. ''We're developing
new and better tests to allow us to do more biomonitoring, but so what?'' he
asked. ''It's really dicey to know what that means for human babies. The mom
who lets her kids get sunburned and worries about PBDE's is worrying about
the wrong thing.''

Knowing what we carry inside us, rather than making anyone feel better, may
in fact be making us feel worse. ''Biomonitoring is now so refined that you
can detect pretty much anything,'' said Peter O'Toole, a spokesman for the
industry-financed Bromine Science and Environmental Forum. ''It's become a
cottage business. We just want to see it done right, and not used as a scare
tactic.''

Fewer than 200 women have been tested in the United States for flame
retardants in their breast milk, many of them for a study by Arnold
Schecter. When he called with my PBDE results from the lab, he had mixed
news. The good news in relative terms is that at 36 parts per billion, my
levels are only 2 points above what Schecter's work suggests is the U.S.
median. This means that roughly half of women tested have levels above mine
and half below. The bad news is that my levels are presumed to be rising
with the current trend and are still an order of magnitude higher than those
of the rest of the industrialized world. At current rates of increase, my
levels could reach 300 parts per billion in 10 to 15 years. That's the level
that Tom McDonald, at the California Office of Environmental Health Hazard
Assessment, says corresponds to endocrine and thyroid dysfunction in lab
animals. What this means, though, in human terms, remains unclear. Talking
about PBDE's, Schecter said, ''We know less than one-tenth of one percent of
what we know about PCB toxicity. Your level, and that of other American
women, suggests to me that the E.P.A. still has a lot of work to do.''

I called Michael Dourson, a toxicology consultant who is very familiar with
the current research on PBDE's and children, to get a read on my own
numbers. He translated my PBDE levels -- 36 parts per billion -- into an
exposure estimate for my breast-feeding daughter and then compared that with
the best-known safe level that scientists can more or less agree on. What it
comes down to is that, roughly and with some uncertainty, my baby is
receiving one-seventh the exposure of the maximum level believed to be safe.
''Above that level, we're not sure, but we become less confident,'' he said.
''And at some point, it becomes not safe.''

After countries in Northern Europe began restricting certain flame
retardants in the 90's, levels in breast milk there declined. That is what
we hope to see here now that production of the two most worrisome flame
retardants has ceased.

I'm relieved that my exposure levels aren't higher. I'm relieved that some
of the substances are going off the market. And I'm relieved, frankly, to
get back to worrying about trans fats and car seats. But there is a
lingering unease that more toxic surprises await us. A few years ago, many
American toxicologists had never heard of polybrominated diphenylethers.
Already, another chemical is ready to claim ''the next PCB'' label: PFOA, or
perfluorooctanoic acid (used to make nonstick frying pans), believed by some
to be an even bigger problem.

Ultimately, though, the question for me as a mother is not at what
threshold of exposure will my baby be harmed, but why are we manufacturing
common products made with these toxins at all? ''There is almost no example
of a toxic chemical in breast milk that doesn't have a nontoxic
substitute,'' said Sandra Steingraber, a visiting scholar at Ithaca College
and author of ''Having Faith: An Ecologist's Journey to Motherhood.'' ''We
haven't yet compromised breast milk to such an extent that it's a worse food
than infant formula, but why get to that point?''

For now, I will continue to breast-feed my daughter. As for PBDE's,
McDonald said, ''My hope is that we caught it early enough.''

Florence Williams, a contributing writer for Outside magazine, writes
frequently about environmental issues.