rachel carson memorial lecture

8/9/2019 Rachel Carson Memorial Lecture

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Rachel Carson is the guiding light for all of us who care about the health of the planetand the people who live on it. With the pub-lication of Silent Spring, Carson provided usfour decades ago with a comprehensiveexhaustively researched biological argumentin simple lyrical language that anyone withor without training in the sciences could readand understand. And everyone did read it. Iwas less than five years old when that book was published in 1962. My father whotaught high school used it as a textbook, andhis students all read it. But more than that, Iremember hearing the bus driver talk about

that book. It was a book that reached acrosssocio-economic lines and truly did changethe way people thought about their relation-ship to the natural world.

The book takes a four-part argument.First, Carson says we are all being contami-nated without our consent to inherently toxicchemicals in the form of pesticides.Secondly, that the risks to our health and thehealth of other species are really needlessbecause there are many non-toxic alterna-tives, if we only looked about us and soughtthem out. And then third, these alternativesare more effective than toxic chemicalsbecause besides all of the unintended conse-

quences of pesticides, the truth is that thesechemical poisons don’t really work verywell in controlling pests. And finally – andthis is the message I would like to elaboratebecause it is in the book and in her lastspeeches before Congress, but it is not thepart that people really remember – she saidwe have the right to know about the risksthat we are being compelled to endure, andonce knowing we have the obligation to act.

Carson died eighteen months after Silent Spring was published. Breast cancersilenced her voice. She was in her midfifties; she was the mother of a young sonand a writer with ideas for many more

books. We had a few things in common.Both of us were formally trained as wildlifebiologists and went on to make our livingwriting about the environment. Both of usare mothers balancing motherhood withresearch and writing. And both of us hadcancer. The important difference is that

Carson had to live in fear that her cancerdiagnosis would be made public, and thather enemies in industry would use herenduring the disease of cancer to discredither scientific objectivity. I cannot imaginethe burden that that must have placed on her:having to swear the few friends she confid-ed in to utter secrecy; enduring the rigours of a book tour and addresses before Congresswearing her wig; trying to hide the effects of the mastectomy and the radiation treatments.Thirty years of feminist thinking span herlife and mine. At this point in history,women’s experiences and the way they live

their lives are considered to be a valid wayof understanding the world. When I blendthe voice of a cancer survivor with theobjective dispassionate voice of a biologist,I have not had to be criticised that my sci-ence was ‘off’ because of my experience of undergoing cancer treatment.

Bhopal disaster horrified worldand led to Right to Know Act inUnited StatesAt the mid point between Carson’s death in1964 and today, 3 December 2003, cameBhopal. It was a wretched enactment of

Carson’s idea. The pesticide plant in Bhopalreleased the raw ingredient for a pesticide,methyl isocyanate, into the air. Eight thou-sand people immediately died. Anothertwelve thousand would die in the years tofollow. No one knew what had happened tothem, not even the doctors treating thepatients knew what had happened becausethere was no right to know. The chemistry of what that pesticide plant was using was atrade secret. And so people died withoutknowing what kind of poison gas hit them.Their doctors struggled to treat them notknowing what antidotes might be possible.That so horrified the world that two years

later in 1986 the United States passed a com-prehensive Right to Know Act on the basisthat toxic chemicals used within factorywalls or released into the environment thatwe all share – either by a terrible accident orthrough routine emissions into air, food, soilor water – form a public gesture and the pub-

lic therefore has the right to know aboutthem. That is now enshrined in the US legis-lation because anyone, including my stu-dents at University, has the ability to dial upa website, type in their zip code and withinthirty seconds have a read out of all the toxicreleases in their home community, fromwhat industry, in what amounts. You canclick on the names of those chemicals andfind out the health effects of being exposed.

It is a very powerful tool for social activismand it was the dead of Bhopal who gave usthat.

Steingraber used new law tofind out what was in her ownback yardIn 1994 while at Harvard University I beganwork on the book Living Downstream. Itried to do two things at once: summarise allthe evidence I understand as a biologist,focusing on environmental contaminants onthe one hand and risk of cancer on the other.Interwoven with the scientific analysis is the

story of my return to my hometown to inves-tigate my own cancer diagnosis as well asthe cancer cluster that was alleged to haveoccurred there. I made use of Right to Knowdata by investigating the toxic emissionsinto the river, into the ground water wells inwhich the drinking water is gathered. I wasable to find out what went on at the pesticidefactory right near my high school, and whatkind of toxic waste is imported to the haz-ardous waste land fill near the house where Igrew up. The knowledge that I gained indoing so and my ability to write about it inmy book Living Downstream was only madepossible by the twenty thousand dead in

Bhopal. And my analysis and my languageand my words were made possible becauseRachel Carson wrote Silent Spring before Idid. So I would like you to join me in amoment of silence for the death of RachelCarson, who lost surely about twenty yearsof her life to breast cancer, and the death of 2

Rachel Carson Memorial Lecture Pesticides News 63 March 2004

Contaminated

without Consent:Why our exposure to chemicals in air, food and water violates human rights

For its first Rachel Carson memorial lecture, Pesticide Action Network UK invited the renowned American campaigner SandraSteingraber to talk about her experiences with pesticides and other toxic pollutants. This is an edited version of her speech in London.



the many thousands of victims in Bhopal.Who knows what stories they might be ableto tell us, what they might be able to writeand explain to us had they not died. And inthat silence perhaps we can each think of away that in our own life we might use ourown voices to speak out against those kindsof human rights abuses.

When I became pregnant at the brink of forty, I had already spent twenty years as achildless adult ecologist and my work wasdevoted mainly to studying the ways in whichorganisms interact with their environment.

My first personal experience of pregnan-cy took me back to the embryology that Ihad studied at university years ago and Ibecame very interested in understanding thethreats to this internal environment. Whatkind of toxic chemicals, what kind of dam-age might be happening to this environmentand what risks to this life form that livedinside me did those exposures create, a lifewhose body was just being assembled forthe first time. It seemed to me that the risksmight be unique and so my interest in thistopic and my pregnancy led me to CornellUniversity where I spent four years studyinga field called foetal toxicology.

Book summarises findings onfoetal toxicology and tellspregnancy storyThe book Having Faith, like Living Downstream, is really two books in one. It

represents my best attempt to summarise thefindings of foetal toxicology and what itmeans for us, but it also tells the story of myown, very joyful pregnancy with my nowfive-year-old daughter, Faith. It is premisedon an idea first coined by a native Americanmidwife named Katsi Cook who lives in myhome state of New York. She said a woman’sbody is a first environment for all of us.

The findings that come out of the field of foetal toxicology are mounting a veryimportant challenge to the historical waysthat we in the US and you in England andalso in the EU have looked at toxic chemi-cals and thought about the ways in which to

manage them. So I will give away my thesisstatement right up front and then would liketo guide you through some of the windowsof vulnerability of human development. Iwill be talking mostly out of my book Having Faith but will include as I go someof my new research on adolescence, pubertyand old age so we will be going through awhole life span and looking at certain risksto human health.

Here is the idea: the old belief was calledthe ‘dose makes the poison’, a phrase origi-nally used by a mediaeval physician namedParacelsus who noticed when treatingsyphilis with mercury, the treatment of

choice, that too much would kill the patient.‘The dose makes the poison’ is still the prin-ciple upon which chemotherapy drugs aregiven to cancer patients. The hope is to givea dose the patient can tolerate, but largeenough to poison the cancer cells. This is avery powerful notion in medicine and in tox-

icology. When a chemical is discovered tobe inherently toxic – perhaps because itcauses miscarriage or infertility, perhapsbecause it is a neurological poison thateffects the brain, perhaps because it is relat-ed to cancer – instead of moving immediate-ly to divorce our economy from dependenceon such a chemical the regulatory system

requires instead laboratory studies (mostlyon animals, but also on possible humanexposure) to decide on the maximum doseallowable in the environment. Exposureroutes could be as a residue in food if it is apesticide, levels allowable in drinking wateror ground water, or how much air pollutioncan we allow. Regulators set these so-calledsafe threshold levels. The idea is that above

these levels there might be human harm, butbelow that the harm is mostly negligible.The new science is showing that the tim-

ing of exposure makes the poison as much ormore than the dose. This draws on the reali-sation that we are not all middle-aged adults;we all begin our lives as embryos and gothrough a life span; and we are not the sameindividual biologically or physiologicallyduring that entire life span. We go through

important changes during our life and enterwindows of vulnerability when we areexquisitely sensitive to the effects of toxicexposures – far out of the proportion that thedose might predict. Embryonic and foetallife is one of those times, and so is infancy.

For example, all of us have somethingcalled the ‘blood brain barrier’ that workspretty well to keep out any pesticide.Insecticides operate on the principal of chemical electrocution. They are all neuro-logical poisons. The blood brain barrier willwork pretty well to ensure that insecticideresidues consumed with your dinner will notleave your blood stream and enter the brainmatter where they can do some more dam-age. However we do not get a blood brainbarrier until we are six months old. Anyoneyounger than six months is missing the suitof armour that surrounds the brain and offerspretty good protection against the neurolog-ical damage of insecticides. So tiny, vanish-ingly small exposures of insecticides tosomeone younger than six months can createdisproportionate risks to the brain, and canbe a terrible saboteur of that brain comparedto similar or even much larger exposures forolder humans.

The human rights implications of thisnew science need to be fleshed out, and letme offer an overarching observation. We arenot providing under the law equal protectionagainst toxic chemicals to all citizens. Thenew science shows that we are discriminatingby age against particular groups of people,

not only the very young but also I hope todemonstrate to you that adolescence, affectedby the hormonal effects of puberty, representsanother window when tiny exposures cancreate disproportionate risks to health. Andold age represents another period when weare exquisitely sensitive to toxic chemicalsbecause we start losing defence mechanisms.The blood brain barrier becomes permeableagain. It starts to fall apart. Liver enzymes are

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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.

PAN staff with Sandra Steingraber (far right) at the Rachel Carson lecture on the Day of No Pesticides, December 3 2003.



from the top down and from the centre out.The heart develops before the arms and thefingers. All of the internal organs in the cen-tre of the body and the head of the bodydevelop faster than those below. The heartdevelops faster than the gonads, for exam-ple. All this takes place in the periodbetween weeks five and ten. At the end of week ten of pregnancy you have a humanbeing the size of apaper clip with all thebody parts present.We have thirty moreweeks to come. Thedanger at this point isa birth defect. Anytoxic chemical thatenters our story at thispoint and interfereswith essentially theprocess of Japaneseorigami that causesthese flat pieces of tis-sue to roll themselvesup and fold them-selves up into threedimensional humanbody structures willaffect the human bodyform in some way.And depending on thelocation of the birth defect we know the tim-ing of what must have gone on. A cleftpalate happens very early on in humandevelopment, and so does a cardiac defect.

Undescended testicles reflect a problemwith the gonads and happen later. Webbed ormissing fingers and toes and missing limbshappen later in development than any mid-line defect.

We have pretty good evidence that expo-sure to pesticides during that week five toten of a human pregnancy is linked to birthdefects. There are good birth defect reg-istries in the UK, better than those in theUnited States. I relied a lot on the UK reg-istry when I looked at birth defects discussedin chapters three and four of Having Faith.Many European countries have good reg-istries: the Swedes are excellent; Finland,

Spain and Italy have nice registries as well.What these data show is that womenexposed to pesticides, either because theywork in farming, nurseries or greenhousesduring the window of time in early pregnan-cy have excess rates of particular kinds of birth defects. This is shown over again, nomatter what the country: certain kinds of clefts, cardiac defects, limb reductiondeficits, undescended testicles and hypospa-dias (when the opening of the penis does nothappen at the tip but by the scrotum or underthe shaft). Good registry data shows timetrends of hypospadias, with good evidencefrom interviews about the kind of exposure

and the jobs of the mothers. Women whowork in certain kinds of agricultural occupa-tions have sons who are at higher risk forthis kind of birth defect. The good registrydata I could use in the US (mostly fromCalifornia and some from Texas andMinnesota) shows similar trends. In

California, the closer a woman lives to anagricultural field where pesticides aresprayed, the higher her risk for stillbirthcaused by birth defects. The highest risk of all is living within a mile of an agriculturalfield that is sprayed with pesticides. InMinnesota, interesting evidence shows thatthe further west you live in the State thehigher the risk of birth defects. The further

west you go, the more intense the agricul-ture. Furthermore, there is an interestingseasonality to the data. Children born tofarmers have high risks of birth defects, buteven higher if their birthdays are in the win-ter: the period of organogenesis correspondsto the spring months of planting when pesti-cide use is the highest. So there is a spike of birth defects among babies born in the win-ter months of December and January. Nowthere is corroborating evidence from Iowa.

Let us presume the body develops in aperfectly healthy way. There is no birthdefect; the next thirty weeks of pregnancy

are devoted to the growth and developmentof all those parts that were formed duringorganogenesis. One of the hallmarks of thatdevelopment occurs in the fifth and sixthmonths of pregnancy when there is a hugespurt in brain growth development. Duringthis month all those brain neurons that were

formed during organogenesis start moving.They migrate. They spin out an axon andtravel down it just like a spider that can pro-pel down from a silken thread from the ceil-ing. And as these spider cells meet eachother they spin the connections which are ahallmark of being human. We do not have somany more brain cells than most other mam-mals but we have far more connectionsbetween those brain cells, and many of thoseare spun in the fifth and sixth months of pregnancy. The danger here is brain damageso if pesticides, or a heavy metal like lead ormercury, enter our story at this point thosebrain cells stop moving. They are paralysed;they cannot find each other and the connec-tions are not made. When the baby is born,its head looks perfectly normal. There is nomalformation, there is no birth defect, butwe cannot see the subtle change in the archi-tecture in the brain underneath and we maynot notice until maybe that child goes toschool that there is a learning disability orbehavioural problem like Attention DeficitDisorder or hyperactivity or autism. We aregetting better at measuring exposure toheavy metals, pesticides and industrial cont-aminants in the umbilical cord blood at birthand then looking at development of the child

through school andseeing, for example,whether exposure tohigh levels of mer-cury prior to birthincreases the need for

special educationalservices. Lead expo-sure before birthincreases the risk of trouble with mathe-matics. Exposed toPCBs before birthshortens attentionspan, or focus to stayon task. Now this isfascinating because itmeans we are chang-ing the nature of theself through exposureto toxic chemicals. A

child is born with adifferent mind than it otherwise would have.Let us go on. Let us go to the very end of

pregnancy. We have emerging evidence tosuggest that certain pesticides as well as cer-tain industrial chemicals can alter the day of birth. We might think that our birthday hassomething to do with our astrological chart.I can tell you as a biologist, that the kind of chemicals that your mother was exposed towhen she was pregnant, probably had asmuch to do with the day that you were bornthan the stars did. That is because certainchemicals such as PCBs and now we suspectDDT not only cross the placenta, but also

can get into the fibres of the uterine muscletissue itself and alter the way calcium flowsthrough that muscle. The flow of calciumthrough any muscle determines whether itwill contract or not. By opening the calciumchannels of the muscle in late pregnancy, theuterine muscle will start contracting sooner

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than it otherwise would, andessentially shortens gestation.Babies are being born early. If thisis more than three weeks beforetheir due date they are officiallyclassified as a pre-term birth andwe are beginning to realise thatthe stubbornly high incidence of pre-term birth in spite of goodpre-natal care in the United Statesmay be related to environmentalexposures. PCBs, that old indus-trial chemical used in electricalfluids, is one of the few oily fluidsthat does not catch on fire and sois used to lubricate electrical partsat high temperature. We nowknow PCBs not only cause birthdefects and cancer but also areofficially classified as chemicalswith the power to shorten humangestation. Being born before youshould is the leading cause of dis-ability in the United States and probably inEngland. It sometimes requires millions of health care dollars to save the lives of thosebabies and just bring them up to their birthdates. Very often, many of them require alifetime of special medical needs and specialeducational needs.

Breast milk is the best food forhuman babies – but it is alsocontaminated

Breastfeeding is probably the trickiest topicin Having Faith. I felt like I was walking ona kind of high wire whilst writing it. Thereare two true things about breast milk, andthey seem mutually contradictory, but theyare not, and it is hard to hold two true thingsthat seem like they contradict each other inyour head at the same time. The first truething about breast milk is that it is absolute-ly the best food for human infants. The dataon the health benefits of breast milk areabsolutely unanimous and that babies whoare breastfed are healthier, they die lessoften in their first year of life and they enjoyhealth benefits for a lifetime thanks to moth-

er’s milk. Breast milk contains antibodiesfrom a woman’s own blood stream that helpprotect against things like pneumonia, diar-rhoea and respiratory diseases in the firstyear of life for reasons we do not fullyunderstand. Breastfed children do not die asoften from cot deaths, sudden infant deathsyndrome, perhaps because they breathe dif-ferently than bottle fed babies. When breast-feeding, breathing patterns are not interrupt-ed. When bottle-feeding, the milk flows outtoo fast, the baby learns to stop its tongueagainst the teat so it does not choke and inthat split second will stop breathing. Perhapsas breathing patterns are set, breastfeeding

allows for a healthier form of breathing thatis not interfered with while the baby sleeps –because cot death usually occurs when thebaby is asleep and forgets to breathe. Theother leading theory is that breastfed babieswake more easily than bottle fed babies sothat they are aroused more. They need to be

fed more during the night until their brainstem mechanism becomes fully mature andthe baby will keep breathing, to the pointwhere it sleeps the night. That is importantto early survival. We do not exactly knowthe mechanism but the data are very clear,that breastfeeding will protect against sud-den infant death syndrome.

But the benefits go on. Breastfed babiesgrow into an individual at lower risk for dia-betes, asthma, allergies, eczema, obesity, juvenile arthritis, Crones disease, and ulcer-ative colitis. There is lower risk for child-hood leukaemia and lymphoma. Babies havehigher IQ and less need for special educa-tion, fewer learning disabilities, better visionand better hearing. But how can that be?There are growth factors in breast milk whose job is not to be digested as food butrather that go through the infant’s gut, gointo the brain and help guide all those stillmigrating neurons after birth to find the rightconnections. Even up to age two, as theinfant brain is still forming breast milk pro-motes good brain growth development. Thatis probably why infants who are breastfedhave better hearing and vision. We believethat the fewer autoimmune problems such asdiabetes and juvenile arthritis may be relat-ed to the immune factors in breast milk.These provide temporary immunity, and gointo an infant’s cells and turn on and turn off certain genes modulating the nascentimmune system so that when the childgrows up, it is better able to distinguishbetween a true pathogen and attack and killit and something that is harmless.

There is nothing else like breast milk.Formula is an inferior pretender. Now I willsay right now, I am not trying to make bot-tle-feeding mothers feel guilty. I am anadoptive child and my own adoptive mother

fed me formula. But on the other hand, theevidence is strong, and on that basis I choseto breastfeed my own daughter Faith forthree years and am now breastfeeding mytwo-year-old son Elijah. I have actually beencontinually lactating now for five long, joy-ful, symbiotic years.

Here is the other true thing about breast

milk. Breast milk, human milk, isthe most chemically contaminat-ed human food on the planet.Why is that? Well, you have tothink like an ecologist. Breastmilk occupies one rung higher onthe human food chain, than thefood that adults eat. What thatmeans is that the milk makinglobules in the back of a nursingmother’s chest wall have onemore chance to concentrate thepoison found in things like toiletdeodorisers, moth-proofingagents, flame retardants, pesti-cides, dioxins, PCBs. These arethe most common contaminantsof breast milk. They are common-ly found in the food, but are ten toa hundred times higher in breastmilk because they are persistentand concentrate as they move upthe food chain. Nursing infants

that feed on their mother’s body eat one runghigher on the food chain than we who eat acombination of animal food and plant basedfood. For that reason, pound for pound,human infants are receiving many highertimes more pesticide residues than we are.When safe levels are set for pesticideresidues in food bought in the supermarket,no one thought ‘what are nursing infantsgoing to receive if we allow this much pesti-cide residues in wheat, that much in sweetpotatoes, this much in eggs, and this much in

fish.’ No one thought that a nursing infantwill get at least ten times that amount inbreast milk. No one regulates breast milk, itis not transported across state boundariesand it is not sold in supermarket shelves. If it were, United States data indicates thatmany women’s breast milk would not beavailable for sale because the amount of deleterious substances found exceed theaccepted levels; the accepted maximum con-taminant levels that allow you to sell some-thing from the supermarket shelf.

So on the one hand, breastfed childrenare healthier, die less often, go on to besmarter, have better eye sight, have fewer

immune problems, and do suffer less fromallergies. On the other hand, measures of theblood of children in school, or who havebeen nursed, even for a period as short as sixweeks, show four to five times more conta-minants than their formula fed counterparts.So our breastfed children are paying a terri-ble price for their right as children to drink their mother’s milk. And the right of themother to feed the child milk from her ownbody is being compromised.

Contaminated breast milk is not killingfour thousand infants a year. A risk benefitanalysis would argue that as long as it iskilling fewer than four thousand, then we

should do nothing. But a human rightsanalysis should say that no child should beharmed by contaminants in mother’s milk. If we can raise the goodness of mother’s milk,then we should do it and we should getchemicals out of milk. The answer is not touse formula milk, but to say that any chemi-

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Michael Meacher, former UK Environment Minister and Chair for the

lecture discusses pesticide issues with David Buffin from PAN UK.

rachel carson memorial lecture

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