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RACHEL
CARSON MEMORIAL LECTURE 3/12/03
Contaminated without Consent:
Why our
exposure to chemicals in air, food and water violates
human rights
Sandra Steingraber
Rachel Carson is the guiding
light for all of us who care about the health of the
planet and the people who live on it. With the
publication of Silent Spring, Carson provided us
four decades ago with a comprehensive exhaustively
researched biological argument in simple lyrical
language that anyone with or without training in the
sciences could read and understand. And everyone did
read it. I was less than five years old when that book
was published in 1962. My father who taught High School
used it as a textbook, and his students all read it. But
more than that, I remember hearing the bus driver talk
about that book. It was a book that reached across
socio-economic lines and truly did change the way people
thought about their relationship to the natural world.
The book takes a four-part
argument. First, Carson says we are all being
contaminated without our consent to inherently toxic
chemicals in the form of pesticides. Secondly, that the
risks to our health and the health of other species are
really needless because there are many non-toxic
alternatives, if we only looked about us and sought them
out. And then third, these alternatives are more
effective than toxic chemicals because besides all of
the unintended consequences of pesticides, the truth is
that these chemical poisons don’t really work very well
in controlling pests. And finally – and this is the
message I would like to elaborate because it is in the
book and in her last speeches before Congress, but it is
not the part that people really remember – she said we
have the right to know about the risks that we are being
compelled to endure, and once knowing we have the
obligation to act.
Carson died eighteen months
after Silent Spring was published. Breast cancer
silenced her voice. She was in her mid fifties; she was
the mother of a young son and a writer with ideas for
many more books. We had a few things in common. Both of
us were formally trained as wildlife biologists and went
on to make our living writing about the environment.
Both of us are mothers balancing motherhood with
research and writing. And both of us had cancer. The
important difference is that Carson had to live in fear
that her cancer diagnosis would be made public, and that
her enemies in industry would use her enduring the
disease of cancer to discredit her scientific
objectivity. I cannot imagine the burden that that must
have placed on her: having to swear the few friends she
confided in to utter secrecy; enduring the rigours of a
book tour and addresses before Congress wearing her wig;
trying to hide the effects of the mastectomy and the
radiation treatments. Thirty years of feminist thinking
that span her life and mine. At this point in history,
women’s experiences and the way they live their lives
are considered to be a valid way of understanding the
world. When I blend the voice of a cancer survivor with
the objective dispassionate voice of a biologist, I have
not had to be criticised that my science was ‘off’
because of my experience of undergoing cancer treatment.
At the mid point between
Carson’s death in 1964 and today, 3 December 2003, came
Bhopal. It was a wretched enactment of Carson’s idea.
The pesticide plant in Bhopal released the raw
ingredient for a pesticide, methyl isocyanate, into the
air. Eight thousand people immediately died. Another
twelve thousand would die in the years to follow. No one
knew what had happened to them, not even the doctors
treating the patients knew what had happened because
there was no right to know. The chemistry of what that
pesticide plant was using was a trade secret. And so
people died without knowing what kind of poison gas hit
them. Their doctors struggled to treat them not knowing
what antidotes might be possible. That so horrified the
world that two years later in 1986 in the United States
passed a comprehensive Right to Know Act on the basis
that toxic chemicals used within factory walls or
released into the environment that we all share – either
by a terrible accident or through routine emissions into
air, food, soil or water – form a public gesture and the
public therefore has the right to know about them. That
is now enshrined in the US legislation because anyone,
including my students at University, has the ability to
dial up a website, type in their zip code and within
thirty seconds have a read out of all the toxic releases
in their home community, from what industry, in what
amounts. You can click on the names of those chemicals
and find out the health effects of being exposed. It’s a
very powerful tool for social activism and it was the
dead of Bhopal who gave us that.
So in 1994 while at Harvard
University I began work on the book Living Downstream.
I tried to do two things at once: summarise all the
evidence I understand as a biologist, focusing on
environmental contaminants on the one hand and risk of
cancer on the other. Interwoven with the scientific
analysis is the story of my return to my hometown to
investigate my own cancer diagnosis as well as the
cancer cluster that was alleged to have occurred there.
I made use of Right to Know data by investigating the
toxic emissions into the river, into the ground water
wells in which the drinking water is gathered. I was
able to find out what went on at the pesticide factory
right near my high school, and what kind of toxic waste
is imported to the hazardous waste land fill near the
house where I grew up. The knowledge that I gained in
doing so and my ability to write about it in my book
Living Downstream was only made possible by the
twenty thousand dead in Bhopal. And my analysis and my
language and my words were made possible because Rachel
Carson wrote Silent Spring before I did. So I
would like you to join me in a moment of silence for the
death of Rachel Carson, who lost surely about twenty
years of her life to breast cancer, and the death of the
many thousands of victims in Bhopal. Who knows what
stories they might be able to tell us, what they might
be able to write and explain to us had they not died.
And in that silence perhaps we can each think of a way
that in our own life we might use our own voices to
speak out against those kinds of human rights abuses.
When I became pregnant at
the brink of forty, I had already spent twenty years as
a childless adult ecologist and my work was devoted
mainly to studying the ways in which organisms interact
with their environment. I first stared at the pregnancy
home test kit that one is required to pee on so that the
monoclonal antibodies that are embedded in that plastic
wand can react with the hormone in the pregnant woman’s
urine, known as human chorionic gonadotropin, causing a
colour change to occur on that plastic stick. The double
lines of purple that appeared in the stick were the
divining rod that told me I was going to have a baby: my
first reaction was “Oh, I am now a habitat!”
After twenty years of studying other habitats I was now
an environment for another organism to live out the
first nine months of its life. I felt that I was a kind
of inland ocean with this marine mammal swimming around
inside of me and I became very interested to know what
was going on in that environment.
And so my first personal
experience of pregnancy took me back to the embryology
that I had studied at university years ago and I became
very interested in understanding the threats to this
internal environment. What kind of toxic chemicals, what
kind of damage might be happening to this environment
and what risks to this life form that lived inside me
did those exposures create, a life whose body was just
being assembled for the first time. It seemed to me that
the risks might be unique and so my interest in this
topic and my pregnancy led me to Cornell University
where I spent four years studying a field called foetal
toxicology. So the book Having Faith, like
Living Downstream, is really two books in one. It
represents my best attempt to summarise the findings of
foetal toxicology and what it means for us but it also
tells the story of my own, very joyful pregnancy with my
now five-year-old daughter, Faith. It is premised on an
idea first coined by a native American midwife named
Katsi Cook who lives in my home state of New York. She
said a woman’s body is a first environment for all of
us.
That is my starting point.
Let me tell you a bit about the kind of paradigm in
science that is challenging the way governments regulate
toxic chemicals. These are findings that come out of the
field of foetal toxicology that are mounting a very
important challenge to the historical ways that we in
the US and you in England and also in the EU have looked
at toxic chemicals and thought about the ways in which
to manage them. So I will give away my thesis statement
right up front and then would like to guide you through
some of the windows of vulnerability of human
development. I will be talking mostly out of my book
Having Faith but will include as I go some of my new
research on adolescence, puberty and old age so we will
be going through a whole life span and looking at
certain risks to human health.
Here is the idea: the old
belief was called the ‘dose makes the poison’, a phrase
originally used by a mediaeval physician named
Paracelsus who noticed when treating syphilis with
mercury, the treatment of choice, that too much would
kill the patient. ‘The dose makes the poison’ is still
the principle upon which chemotherapy drugs are given to
cancer patients. The hope is to give a dose the patient
can tolerate, but large enough to poison the cancer
cells. This is a very powerful notion in medicine and in
toxicology. When a chemical is discovered to be
inherently toxic – perhaps because it causes miscarriage
or infertility, perhaps because it is a neurological
poison that effects the brain, perhaps because it is
related to cancer – instead of moving immediately to
divorce our economy from dependence on such a chemical
the regulatory system requires instead laboratory
studies (mostly on animals, but also on possible human
exposure) to decide on the maximum dose allowable in the
environment. Exposure routes could be as a residue in
food if it is a pesticide, levels allowable in drinking
water or ground water, or how much air pollution can we
allow. Regulators set these so-called safe threshold
levels. The idea is that above these levels there might
be human harm, but below that the harm is mostly
negligible.
The new science is showing
that the timing of exposure makes the poison as much or
more than the dose. This draws on the realisation that
we are not all middle-aged adults; we all begin our
lives as embryos and go through a life span; and we are
not the same individual biologically or physiologically
during that entire life span. We go through important
changes during our life and enter windows of
vulnerability when we are exquisitely sensitive to the
effects of toxic exposures – far out of the proportion
that the dose might predict. Embryonic and foetal life
is one of those times, and so is infancy.
For example, all of us have
something called the ‘blood brain barrier’ that works
pretty well to keep out any pesticide. Insecticides
operate on the principal of chemical electrocution. They
are all neurological poisons. The blood brain barrier
will work pretty well to ensure that insecticide
residues consumed with your dinner will not leave your
blood stream and enter the brain matter where they can
do some more damage. However we do not get a blood brain
barrier until we are six months old. Anyone younger than
six months is missing the suit of armour that surrounds
the brain and offers pretty good protection against the
neurological damage of insecticides. So tiny,
vanishingly small exposures of insecticides to someone
younger than six months can create disproportionate
risks to the brain, and can be a terrible saboteur of
that brain compared to similar or even much larger
exposures for older humans.
The human rights
implications of this new science need to be fleshed out,
and let me offer an overarching observation. We are not
providing under the law equal protection against toxic
chemicals to all citizens. The new science shows that we
are discriminating by age against particular groups of
people, not only the very young but also I hope to
demonstrate to you that adolescence, affected by the
hormonal effects of puberty, represents another window
when tiny exposures can create disproportionate risks to
health. And old age represents another period when we
are exquisitely sensitive to toxic chemicals because we
start losing defence mechanisms. The blood brain barrier
becomes permeable again. It starts to fall apart. Liver
enzymes are no longer as efficient. The kidneys are not
detoxifying as effectively. The immune system becomes
compromised. So the very old and the very young
physiologically resemble each other to a large degree
and then in the middle you have the experience of
puberty and adolescence which for very different reasons
also represents a vulnerable window of time. I argue
that our current model of regulation does not
sufficiently protecting these three groups: the very
young, teenagers and the elderly.
Now comes the time where I
explain where babies come from. Let us start when an egg
and a sperm find each other at the upper reaches of the
fallopian tube. You might know it takes about five days
to a week for that little gondola boat to float down the
canal of the fallopian tube where it opens out into the
delta of the uterus and implants itself. So about a week
between the fertilisation and the period of implantation
occurs when that embryo actually buries itself into the
wall of the uterus. We start off as a one-celled
organism; by the time the fertilised egg floats out into
the uterus it is 58 cells big. Those 58 cells are
arranged in a little ball called the morula which buries
itself in the uterine lining. Morula is the Latin for
mulberry because it’s exactly what it looks like. The
lining grows right up over the top of it and then long
siphoning tubes are sent out from the morula into the
blood filled lining of the uterus and those long
siphoning tubes break open the tips of the spiral
arteries as they snake through the uterus. Those
arteries begin to gush blood, so even before the
placenta and the umbilical cord and the life support
system of the embryo is established, life begins in a
pool of blood. This bloody lagoon created by the
breaking open of these arteries nurtures the new life
form until the life support system develops in the weeks
to follow.
Before we continue the story
let us look at threats to human life right at the very
start: the stage of egg and the sperm. Women who smoke
go into menopause on average two to three years earlier
than women who do not. Something about smoking shortens
the fertile life span of a woman: we now know the agent
behind this is a chemical in tobacco smoke called
benzoapyrene that cycles around the blood, gets into the
chromosomes of the eggs, flips certain genetic switches,
and programmes cell death. So we know that cells can
commit programmed suicide. The threat is called
apoptosis. Benzoapyrene in cigarette smoke has this
effect on human eggs in the ovary and shortens the
fertile life span of women smokers. Researchers began to
wonder whether the benzoapyrene in diesel exhaust and in
coal burning power plant emissions might be having the
same effect. I do not have an answer for you yet: but we
know it is true for laboratory animals. Laboratory rats
exposed to benzoapyrene in the ambient air of their
cages at levels in some of our larger industrial cities,
experience a shortening of fertile life.
Sperm also are not immune to
these effects. Studies of men exposed to pesticides
through drinking water in some agricultural areas in the
United States have lower sperm quantity and lower sperm
quality. These men are not farmers, but are simply
living in farming areas and drinking the water in rural
communities. We also know that males who have exposure
to certain kinds of industrial chemicals, such as diesel
and kerosene, father children who are at much higher
risk for certain kind of paediatric cancers. In some
cases, their children have ten-fold the risk, for
example of neuroblastoma, a childhood cancer that tends
to kill the very young. Children of men with these
occupational exposures are ten times more likely to be
diagnosed with neuroblastoma in the first two years of
life than children of men of a similar socio-economic
backgrounds and classes but who do not have such
exposures.
But let us continue our
story. Let us assume that there is a viable egg and
sperm. Fertilisation occurs, grows into a morula and
begins to implant itself in the lining of the uterus.
The risk of exposure at this point in our story is not
infertility but spontaneous abortion. Here we have an
important human rights issue and a possible conversation
with the right to life community. I am not a member of
this community. I am very much in the other camp. I
believe very strongly that motherhood is the hardest job
in the world. It is a lot harder to be a mother than it
was to write my doctoral dissertation and I entered into
it joyfully and through my own choice. I do not think
any woman should be forced into it against her will. But
whatever your thoughts or opinions on that topic, we
might agree that if you become pregnant wilfully and
with great joy, and then experience a spontaneous
miscarriage because of a chemical that you were exposed
to earlier on in your pregnancy, this is a violation of
human rights, a violation of foetal protection and a
violation of a woman’s ability to choose to have a
child. It is a form of chemical abortion. Evidence
suggests that solvents and pesticides that enter into
the story of pregnancy in the first few weeks raise the
risk of interfering with the chemical cascade that has
to occur: these are chemical messages that flow from one
cell to another in the morula and as the morula turns
into embryo with the extra embryonic membranes such as a
chorion, amnion, allantoic sac, placenta, umbilical
cord. All these require a choreography of messages being
sent back and forth between the cells in the embryo and
interference will cause this new life form to be flushed
from the system because implantation does not take place
properly.
Let us go on with our story.
Let us assume that a miscarriage does not occur, that
implantation successfully happens. Now we are at about
week five of a human pregnancy as midwives and
obstetricians would date it. What happens next is a
period called organogenesis. This takes place between
weeks five and ten of a human pregnancy and during this
time the entire human body is assembled, developing from
the top down and from the centre out. The heart develops
before the arms and the fingers. All of the internal
organs in the centre of the body and the head of the
body develop faster than those below. The heart develops
faster than the gonads, for example. All this takes
place in the period between weeks five and ten. At the
end of week ten of pregnancy you have a human being the
size of a paper clip with all the body parts present. We
have thirty more weeks to come. The danger at this point
is a birth defect. Any toxic chemical that enters our
story at this point and interferes with essentially the
process of Japanese origami that causes these flat
pieces of tissue to roll themselves up and fold
themselves up into three dimensional human body
structures will affect the human body form in some way.
And depending on the location of the birth defect we
know the timing of what must have gone on. A cleft
palate happens very early on in human development, and
so does a cardiac defect. Undescended testicles reflect
a problem with the gonads and happen later. Webbed or
missing fingers and toes and missing limbs happen later
in development than any midline defect.
We have pretty good evidence
that exposure to pesticides during that week five to ten
of a human pregnancy is linked to birth defects. There
are good birth defect registries in the UK, better than
those in the United States. I relied a lot on the UK
registry when I looked at birth defects discussed in
chapters three and four of Having Faith. Many
European countries have good registries: the Swedes are
excellent; Finland, Spain and Italy have nice registries
as well. What these data show is that women exposed to
pesticides, either because they work in farming,
nurseries or greenhouses during the window of time in
early pregnancy have excess rates of particular kinds of
birth defects. This is shown over again, no matter what
the country: certain kinds of clefts, cardiac defects,
limb reduction deficits, undescended testicles and
hypospadias (when the opening of the penis does not
happen at the tip but by the scrotum or under the
shaft). Good registry data shows time trends of
hypospadias, with good evidence from interviews about
the kind of exposure and the jobs of the mothers. Women
who work in certain kinds of agricultural occupations
have sons who are at higher risk for this kind of birth
defect. The good registry data I could use in the US
(mostly from California and some from Texas and
Minnesota) shows similar trends. In California, the
closer a woman lives to an agricultural field where
pesticides are sprayed, the higher her risk for
stillbirth caused by birth defects. The highest risk of
all is living within a mile of an agricultural field
that is sprayed with pesticides. In Minnesota,
interesting evidence shows the that further west you
live in the State the higher the risk of birth defects.
The further west you go, the more intense the
agriculture. Furthermore, there is an interesting
seasonality to the data. Children born to farmers have
high risks of birth defects, but even higher if their
birthdays are in the winter: the period of organogenesis
corresponds to the spring months of planting when
pesticide use is the highest. So there is a spike of
birth defects among babies born in the winter months of
December and January. Now there is corroborating
evidence from Iowa.
So let us continue with our
story. Let us presume the body develops in a perfectly
healthy way. There is no birth defect; the next thirty
weeks of pregnancy are devoted to the growth and
development of all those parts that were formed during
organogenesis. One of the hallmarks of that development
occurs in the fifth and sixth months of pregnancy when
there is a huge spurt in brain growth development.
During this month all those brain neurons that were
formed during organogenesis start moving. They migrate.
They spin out an axon and travel down it just like a
spider that can propel down from a silken thread from
the ceiling. And as these spider cells meet each other
they spin the connections which are a hallmark of being
human. We do not have so many more brain cells than most
other mammals but we have far more connections between
those brain cells, and many of those are spun in the
fifth and sixth months of pregnancy. The danger here is
brain damage so if pesticides, or a heavy metal like
lead or mercury, enter our story at this point those
brain cells stop moving. They are paralysed; they cannot
find each other and the connections are not made. When
the baby is born, its head looks perfectly normal. There
is no malformation, there is no birth defect, but we
cannot see the subtle change in the architecture in the
brain underneath and we may not notice until maybe that
child goes to school that there is a learning disability
or behavioural problem like Attention Deficit Disorder
or hyperactivity or autism. We are getting better at
measuring exposure to heavy metals, pesticides and
industrial contaminants in the umbilical cord blood at
birth and then looking at development of the child
through school and seeing, for example, whether exposure
to high levels of mercury prior to birth increases the
need for special educational services. Lead exposure
before birth increases the risk of trouble with
mathematics. Exposed to PCBs before birth shortens
attention span, or focus to stay on task. Now this is
fascinating because it means we are changing the nature
of the self through exposure to toxic chemicals. A child
is born with a different mind than it otherwise would
have.
Let us go on. Let us go to
the very end of pregnancy. We have emerging evidence to
suggest that certain pesticides as well as certain
industrial chemicals can alter the day of birth. We
might think that our birthday has something to do with
our astrological chart. I can tell you as a biologist,
that the kind of chemicals that your mother was exposed
to when she was pregnant, probably had as much to do
with the day that you were born than the stars did. That
is because certain chemicals such as PCBs and now we
suspect DDT not only cross the placenta, but also can
get into the fibres of the uterine muscle tissue itself
and alter the way calcium flows through that muscle. The
flow of calcium through any muscle determines whether it
will contract or not. By opening the calcium channels of
the muscle in late pregnancy, the uterine muscle will
start contracting sooner than it otherwise would, and
essentially shortens gestation. Babies are being born
early. If this is more than three weeks before their due
date they are officially classified as a pre-term birth
and we are beginning to realise that the stubbornly high
incidence of pre-term birth in spite of good pre-natal
care in the United States may be related to
environmental exposures. PCBs, that old industrial
chemical used in electrical fluids, is one of the few
oily fluids that does not catch on fire and so is used
to lubricate electrical parts at high temperature. We
now know PCBs not only cause birth defects and cancer
but also are officially classified as chemicals with the
power to shorten human gestation. Being born before you
should is the leading cause of disability in the United
States and probably in England. It sometimes requires
millions of health care dollars to save the lives of
those babies and just bring them up to their birth
dates. Very often, many of them require a lifetime of
special medical needs and special educational needs.
Let us talk about
breastfeeding, and then I want to mention puberty and
old age and the new research I am doing. Breastfeeding
is probably the trickiest topic in Having Faith.
I felt like I was walking on a kind of high wire whilst
writing it. There are two true things about breast milk,
and they seem mutually contradictory, but they are not,
and it is hard to hold two true things that seem like
they contradict each other in your head at the same
time. The first true thing about breast milk is that it
is absolutely the best food for human infants. The data
on the health benefits of breast milk are absolutely
unanimous and that babies who are breastfed are
healthier, they die less often in their first year of
life and they enjoy health benefits for a lifetime
thanks to mother’s milk. Breast milk contains antibodies
from a woman’s own blood stream that help protect
against things like pneumonia, diarrhoea and respiratory
diseases in the first year of life for reasons we do not
fully understand. Breastfed children do not die as often
from cot deaths, sudden infant death syndrome, perhaps
because they breathe differently than bottle fed babies.
When breastfeeding, breathing patterns are not
interrupted. When bottle-feeding, the milk flows out too
fast, the baby learns to stop its tongue against the
teat so it does not choke and in that split second will
stop breathing. Perhaps as breathing patterns are set,
breastfeeding allows for a healthier form of breathing
that is not interfered with while the baby sleeps –
because cot death usually occurs when the baby is asleep
and forgets to breathe. The other leading theory is that
breastfed babies wake more easily than bottle fed babies
so that they are aroused more. They need to be fed more
during the night until their brain stem mechanism
becomes fully mature and the baby will keep breathing,
to the point where it sleeps the night. That is
important to early survival. We do not exactly know the
mechanism but the data are very clear, that if
breastfeeding will protect against sudden infant death
syndrome.
But the benefits go on.
Breastfed babies grow into an individual at lower risk
for diabetes, asthma, allergies, eczema, obesity,
juvenile arthritis, Crones disease, and ulcerative
colitis. There is lower risk for childhood leukaemia and
lymphoma. Babies have higher IQ and less need for
special education, fewer learning disabilities, better
vision and better hearing. But how can that be? There
are growth factors in breast milk whose job is not to be
digested as food but rather that go through the infant’s
gut, go into the brain and help guide all those still
migrating neurons after birth to find the right
connections. Even up to age two, as the infant brain is
still forming breast milk promotes good brain growth
development. That is probably why infants who are
breastfed have better hearing and vision. We believe
that the fewer autoimmune problems such as diabetes and
juvenile arthritis may be related to the immune factors
in breast milk. These provide temporary immunity, and go
into an infant’s cells and turn on and turn off certain
genes modulating the nascent immune system so that when
the child grows up, it is better able to distinguish
between a true pathogen and attack and kill it and
something that is harmless.
There is nothing else like
breast milk. Formula is an inferior pretender. Now I
will say right now, I am not trying to make
bottle-feeding mothers feel guilty. I am an adoptive
child and my own adoptive mother fed me formula. But on
the other hand, the evidence is strong, and on that
basis I chose to breastfeed my own daughter Faith for
three years and am now breastfeeding my son two-year-old
son Elijah. I have actually been continually lactating
now for five long, joyful, symbiotic years.
Here is the other true thing
about breast milk. Breast milk, human milk, is the
most chemically contaminated human food on the planet.
Why is that? Well, you have to think like an ecologist.
Breast milk occupies one rung higher on the human food
chain, than the food that adults eat. What that means is
that the milk making lobules in the back of a nursing
mother’s chest wall have one more chance to concentrate
the poison found in things like toilet deodorisers,
moth-proofing agents, flame retardants, pesticides,
dioxins, PCBs. These are the most common contaminants of
breast milk. They are commonly found in the food, but
are ten to a hundred times higher in breast milk because
they are persistent and concentrate as they move up the
food chain. Nursing infants that feed on their mother’s
body eat one rung higher on the food chain than we who
eat a combination of animal food and plant based food.
For that reason, pound for pound, human infants are
receiving many higher times more pesticide residues than
we are. When safe levels are set for pesticide residues
in food bought in the supermarket, no one thought “what
are nursing infants going to receive if we allow this
much pesticide residues in wheat, that much in sweet
potatoes, this much in eggs, and this much in fish.” No
one thought that a nursing infant will get at least ten
times that amount in breast milk. No one regulates
breast milk, it is not transported across state
boundaries and it is not sold in supermarket shelves. If
it were, United States data indicates that many women’s
breast milk would not be available for sale because the
amount of deleterious substances found exceed the
accepted levels; the accepted maximum contaminant levels
that allow you to sell something from the supermarket
shelf.
So on the one hand,
breastfed children are healthier, die less often, go on
to be smarter, have better eye sight, have fewer immune
problems, and do suffer less from allergies. On the
other hand, measures of the blood of children in school,
or who have been nursed, even for a period as short as
six weeks, show four to five times more contaminants
than their formula fed counterparts. So our breastfed
children are paying a terrible price for their right as
children to drink their mother’s milk. And the right of
the mother to feed the child milk from her own body is
being compromised. The goodness of that milk is being
compromised by the presence of contaminants. I want to
be careful and say that we have not yet contaminated
mother’s milk to the point where it is a worse food for
babies than formula – but do we want to let it get to
that point? The United States has terrible breastfeeding
rates, we have the worst in the world, I think, of
developed countries, because we fail to give women paid
maternity leave. Formula feeding is thought to kill at
least four thousand infants a year in the United States.
In other words if we enabled all women to breastfeed
there would be four thousand less deaths of infants
under the age of one every year in the US.
Contaminated breast milk is
not killing four thousand infants a year. A risk benefit
analysis would argue that as long as it is killing fewer
than four thousand, then we should do nothing. But a
human rights analysis should say, that no child should
be harmed by contaminants in mother’s milk. If we can
raise the goodness of mother’s milk, then we should do
it and we should get chemicals out of milk. The answer
is not to use formula milk, but to say that any chemical
that is (a) known to be inherently toxic, and (b) known
to accumulate in mother’s milk, has no place in the
twenty first century economy and we need to immediately
phase out any dependency that our economy has, whether
industrial or agricultural on the use of this chemical.
Some words about puberty.
This amazing rite of passage between childhood and
adulthood is made possible by parts per billion
concentration of steroidal hormones. You might remember
the profound effects that puberty had on your psyche,
your body, your thoughts, and your emotional life. Just
parts per billion concentration of hormones elicited
this huge change. We do not know a lot about the biology
of puberty yet. But we do know that the body is growing
rapidly, the skeleton is being mineralised and cells are
dividing fast, so a lot of DNA is replicating. Whenever
DNA replicates, it is more vulnerable to injury than
when in its quiet state. All kinds of parts of the body
develop hormone receptors so that they can become
targets of hormones such as oestrogen, testosterone or
some of the hormones that your adrenal gland is
producing, your pituitary gland, your thyroid gland. Not
just gonads, but all these glands in the body from your
brain to your thyroid to your adrenal gland that sit on
the back of your kidney are all playing a role in this
great hormonal response that is going on. We in the
biological community are worried about the effect that
endocrine disrupting chemicals in the environment might
be playing on this body that is primed to respond to
hormones, because we know that there are chemicals out
there that have the ability to mimic hormones inside the
human body.
The question is whether
exposures to certain kinds of pesticides are altering
the timing and experience of puberty. And the data are
just beginning to come in. In Belgium some provocative
work shows that immigrant children from developing
nations that still use DDT and live in certain
neighbourhoods are at high risk for premature or
precocious puberty – girls developing breasts before the
age of eight or nine. They have an eighty fold higher
risk. On the other hand girls who are growing up in
those countries, who still presumably have these
exposures, do not develop precocious puberty. Nor is
precocious puberty found in the native born Belgian
children living in the same neighbourhood. So what might
be happening is some kind of interaction between
nutrition and pesticide exposure. Pesticide exposure
early in life is priming the body in such a way that if,
later in life, nutritional status goes up, you get
precocious puberty. Whereas children who remain in
developing countries and consume a limited number of
calories, do not experience precocious puberty, nor do
the children who have plenty of calories but do not have
pesticide exposure. It takes both high nutritional
status and pesticide exposure to elicit this problem. A
lot of work remains to tease apart the effects of high
nutritional status, changing experience and timing of
puberty, and the interactive effects of environmental
chemicals. Now in the US we have terrible rising rates
of childhood obesity, we do not yet know if that is
driving the apparent rise in early puberty, or whether
that is acting together with something like pesticide
exposures. I am now looking at the data in this area.
A word about old age. One of
the things that interests me is dementia. And again,
autobiography drives my science; my own dear adopted
father was diagnosed quite a long time ago with
Parkinson’s disease. It developed, as in the case of 30
per cent of Parkinson’s patients, into full-blown
dementia. Just this year he was institutionalised in a
nursing home. One of the things that people with
Parkinson’s dementia often suffer from are delusions and
hallucinations. My father became deluded that my mother,
his own dear, beloved wife of 57 years, who he worships,
was having an affair. He followed her around shouting
accusations and my sister and I were worried for her
safety. My father was a veteran of World War II and
served in a distinguished way in Italy, and he began to
relive his war life. The combination of believing that
he was in the War and that my mother was cheating on him
was a dangerous combination that led to our family’s
decision. This leads to questions about the role the
environment might play in dementia. Some preliminary
evidence, mostly from the UK, from laboratory animals,
shows that early life exposures to certain kinds of
pesticides, is associated with Parkinson’s dementia.
Laboratory animals exposed early in life, followed by an
exposure in adult life, have two injuries to the brain,
one very early and one later. The combination can elicit
the cascade of neuro-degenerative changes leading to
full blown Parkinson’s. There is something about silent
toxicities early in life, matched by exposures in adult
life, that elicit changes and appear to be behind
Parkinson’s dementia.
All this, of course, is in
controlled animal studies. However, we also know that
certain kinds of farmers are more prone to dementia than
other people and that certain kinds of veterans of wars
where pesticides were used, such as the Vietnam War are
at higher risk for Parkinson’s. Now we are looking
closely at the Gulf War veterans. The first, as far as I
am concerned misguided, of the two military ventures in
Iraq in 1991 has led to an entire generation of disabled
veterans. Lou Gehrig’s Disease, or what is called ALS,
is one neuro-degenerative disease that these veterans
appear to suffer from and perhaps Parkinson’s is another
one. We have new evidence to suggest that welding metals
may put some welders at higher risk than the general
population. So right now provocative evidence from both
human and animal studies suggests environmental links to
Parkinson’s disease. I am now looking closely at the
data, and I would like to expand that to include
Alzheimer’s disease. I have not yet cast my net there,
but I would like to look at the entire human spectrum,
the ways in which we enter and leave these vulnerable
times, and the human rights problems connected to
exposures during these periods of time.
More importantly, I would
like to look at ways in which we can re-cast our entire
regulatory system, our entire way of delivering goods
and services, and of growing foods so that we no longer
need to use toxic chemicals. We can, as Rachel Carson
encouraged, seek out alternatives and to stop taking
counsel from those who tell us that the only way is to
use poisons.
I always close my lectures
with a short reading from one of the more lyrical and
joyful passages of my books. I want to remind us that
when all is said and done, this is really about human
life and its joy. Behind every data point, is a human
life and that is the reason for our interested. This is
from chapter four of Living Downstream. This is
the scene of my own amniocentesis with Faith.
Amniocentesis is more routinely practised in the US than
here, for better or worse. It is a procedure offered to
what they call elderly prima gravida, meaning old
mothers, like myself and in it about 30ccs or one short
glassful of amniotic fluid is removed from the belly of
a pregnant woman. In that fluid is contained skin cells
of the foetus, which can be cultured and grown to show
the DNA, to see if there are any gross chromosomal
abnormalities. The woman can make her decisions based on
those results. So I underwent this procedure and here is
what happened after that.
The needle is out. We’re
done. The mood is still upbeat. The obstetrician hands
the pair of vials to the technician, who holds them up
to the light like glasses of fine wine.
‘Nice colour,’ she says.
‘Do you want to hold them?’ And she passes the vials,
hot as blood, into my hands. The fluid inside is pale
gold, it seems to glow. ‘Well, it’s like liquid amber!’
I sputter, ‘Like an amber jewel.’ It occurs to me that
amniotic fluid might be the loveliest substance I have
ever seen.
The obstetrician touches my
arm, ‘That’s baby pee,’ she says, smiling. ‘We like it
yellow. It’s a sign of good kidney functioning’. I look
at the vials again, Oh right. …
The obstetrician is
finishing up, she reminds me to drink plenty of water
today. Drink plenty of water. Before it is baby pee,
amniotic fluid is water. I drink water and it becomes
the blood plasma which suffuses through the amniotic sac
and surrounds the baby – who also drinks it.
And what is it before
that? Before it is drinking water, amniotic fluid is the
creeks and rivers that fill reservoirs. It is the
underground water that fills wells. And before it is
creeks and rivers and ground water, amniotic fluid is
rain. When I hold in my hands a tube of my own amniotic
fluid, I am holding a tube full of rain drops. Amniotic
fluid is also the juice of oranges that I had for
breakfast, and the milk that I poured over my cereal,
and the honey I stirred into my tea. It is inside the
green cells of spinach leaves and the damp flesh of
apples. It is in the yoke of an egg. When I look at
amniotic fluid and I am looking at rain falling on
orange groves, I am looking at melon fields, potatoes in
wet earth, frost on pasture grasses. The blood of cows
and chickens is in this tube. The nectar gathered by
bees and humming birds is in this tube. Whatever is
inside humming bird eggs is also inside my womb.
Whatever is in the world’s water is here in my hands.
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