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From:
"Katherine A. Dettwyler" <[log in to unmask]>
Reply To:
Lactation Information and Discussion <[log in to unmask]>
Date:
Wed, 15 Oct 1997 15:10:01 -0500
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>LEAVEN, Vol. 30 No. 3, May-June 1994, p. 37
>
>"Minimizing Contaminant Risks During Pregnancy and Lactation"
>
>by Betty Crase
>
>1. Thoroughly wash and peel fruits and vegetables to eliminate the hazard
>of pesticide residues on the skins;
>
>2. Limit your intake of dairy products, realizing that the lower the
>butter fat, the lower the potential burden of fat-soluble contaminants;
>
>3. Reduce consumption of red meats, taking care to trim off excess fat
>which contains contaminants;
>
>4. Remove skin and excess fat from chicken;
>
>5. Avoid freshwater fish and other marine animals from known contaminated
>waters to avoid PCBs and mercury, in particular;
>
>6. Eat foods lower on the food chain, for example, eating grain rather
>than eating beef or other animals that have been fed grains;
>
>7. Avoid excessive weight loss through crash dieting which suddenly
>releases greater amounts of the fat-soluble contaminants, such as PCBs,
>into the bloodstream;
>
>8. Avoid smoking cigarettes and drinking alcohol as levels of
>contaminants have been found to be higher in those who smoke and drink;
>
>9. Limit the use of home, garden, and lawn pesticides as these are
>related to increased levels of DDT in breast milk; be sure to discard
>containers in the garage and workroom as these are possible sources of
>direct exposure to curious children;
>
>10. Discontinue the use of cosmetics made from contaminated raw materials
>such as lanolin prepared from the wool fat of sheep treated with
>persistent pesticides; use only a medical grade of lanolin such as
>Lansinoh(R) for sore or cracked nipples during breastfeeding;
>
>11. Avoid homes and buildings that have been treated for termites with
>chlordane or dieldrin;
>
>12. Avoid contact with incineration smoke and ash, preserved wood, or
>produce grown near incinerators; incineration discharge contains almost
>the full spectrum of chemical and industrial toxins, including the heavy
>metals.
>
>13. Avoid occupational exposure to chemical contaminants, demand that the
>workplace set safety standards considering pregnant and lactating women
>as the models.
>
>14. Beware of indoor pollution and high levels of PCBs, especially in
>kitchens and offices with electric installations.
>
>Betty Crase, BA, IBCLC, has been an LLL Leader for 17 years and is the
>manager of LLLI's Breastfeeding Reference Library & Database. This
>article features some of the highlights from a presentation she gave at
>an environmental conference entitled "Pesticides: Alternatives and
>Solutions," held in February 1994 in Chicago, Illinois, USA, cosponsored
>by a number of national environmental organizations.
>
>[Note: this list was part of the longer LEAVEN article "Pesticides and
>Breastfeeding," also available on the TLC LEAVEN files.]
>
>
>
>
>LEAVEN, Vol. 30 No. 3, May-June 1994, pp. 37-40
>
>"Pesticides and Breastfeeding", Part 1
>
>by Betty Crase
>
>Very few people any longer dispute the basic physiological and
>psychological superiority of human milk and breastfeeding. In this
>contaminated world in which we live, however, some wonder if human milk
>and breastfeeding can still be unequivocally recommended for every mother
>and baby? And what about the alternative for baby, infant formula? What
>steps can a woman take during pregnancy and lactation to minimize her, and
>consequently her developing baby's, exposure to pesticides and other
>organochlorine environmental toxins, such as DDT, DDE, PCBs and associated
>dioxins and furans, heavy metals such as lead, cadmium, and mercury, and
>others? Let's begin by taking a look at what we already know and what we
>must make our best educated guesses about for the future.
>
>One well known and respected researcher in the contaminant field, Dr.
>Walter Rogan, works for the Epidemiology Branch of the National Institute
>of Environmental Health Sciences, Research Triangle Park, North Carolina.
>Along with his colleagues, Dr. Rogan has spent fifteen years doing a
>prospective, ongoing study of North Carolina mothers and their children.
>It is interesting to see how his research has progressed and his
>viewpoint has changed over the years.
>
>In 1980 in the New England Journal of Medicine, Dr. Rogan reviewed what
>was then known about "Pollutants in Breast Milk," namely PCBs and the
>pesticides DDT, dieldrin, heptachlor, and chlordane. He began by
>reiterating that these chlorinated pesticides are lipid soluble,
>gradually accumulating in the general population's body fat over
>long-term exposure and being concentrated in the lipids of human milk. As
>a matter of fact, lactation is the main route of elimination of these
>persistent chemicals from the female body.
>
>He also pointed out that it's very difficult to accurately quantify the
>amounts of these organohalides in breast milk because levels vary widely
>from the beginning of a feed to the end, as well as throughout the day in
>any one sample of breast milk from any one woman. The findings of
>different research studies are also difficult to compare depending on
>whether reported contaminant levels were determined from whole milk or
>milk fat, which can give substantially higher values.
>
>Dr. Rogan examined a number of previous studies which found that PCBs and
>DDT and its derivatives were present in virtually all human milk samples
>from all over the world, even though DDT was banned in the USA in 1972
>and PCBs in 1976. They are still in widespread use in other areas of the
>world.
>
>PCBs, used mainly in the electrical industry as transformer-insulating
>fluids, leaked in huge concentrations into rice oil in Japan and Taiwan
>in the late 1960s and 1970s, respectively. Adult health consequences
>included an acne-like rash, headache, nausea, and diarrhea. Newborns were
>small for gestational age, had dark skin pigmentation, conjunctivitis,
>and jaundice. Children who were breastfed had higher blood levels of PCBs
>and levels increased with the duration of breastfeeding. Follow-up of
>some of these children at about nine years showed slight but clinically
>significant neurologic and developmental impairment. This was an unusual
>exposure, not an everyday occurrence.
>
>There were no reports of DDT toxicity in either occupationally exposed
>workers or experimentally exposed volunteers receiving doses considerably
>greater than in the general population.
>
>Animal studies were a different story, however, but Dr. Rogan cautioned
>about equating effects in animals with humans. Animal infants,
>particularly monkeys, have less body fat than human infants, so
>contaminants are more likely to attack target organs.
>
>Rogan acknowledged that further studies needed to be done, and he has
>proceeded to do one of the best.
>
>In 1986, Rogan and others published the first in a continuing series of
>reports on milk samples from about 900 women in North Carolina and the
>development of their children, born between 1978 and 1982. This 1986
>study published in the American Journal of Public Health specifically
>measured levels of PCBs and DDE in human milk, blood, and other body
>tissues at birth, six weeks, three months and six months, and from some
>of the mothers, at one year, and eighteen months.
>
>Almost all samples showed detectable levels of both PCBs and DDE. The
>highest levels were in older women, Black women, first-time mothers,
>cigarette smokers, and alcohol drinkers. PCBs, in particular, were higher
>in women consuming sport fish during pregnancy. Another important finding
>was the decline in contaminant levels in the milk during the course of
>lactation and with the number of children breastfed.
>
>A second study in 1986 published in the Journal of Pediatrics, was the
>first to report on about 900 of the North Carolina children and the
>"Neonatal effects of transplacental exposure to PCBs and DDE." There were
>no associations between PCB and DDE levels and birth weight, head
>circumference, and hyperbilirubinemia. The Brazelton Neonatal Behavioral
>Assessment Scales were administered after birth. Both chemicals were
>associated with hyporeflexia (lower reflex response). Higher PCB levels
>were also associated with hypotonicity (lower muscle tone). At that time,
>Rogan expressed concern about continued exposure to PCBs and DDE through
>breastfeeding.
>
>In 1987, the next report followed the children to one year of age; it was
>published in the American Journal of Public Health. The purpose of the
>study was to ascertain if the presence of PCBs and DDE in their mothers'
>milk had affected these children's growth or health. Neither chemical
>showed an adverse effect on weight or frequency of doctors' visits for
>illness, although differences were seen between breastfed and bottle-fed
>children. Bottle-fed children tended to weigh more and have more frequent
>gastroenteritis and otitis media.
>
>In 1988 in the Journal of Pediatrics, it was reported that the children
>were examined for any mental and psychomotor developmental effects at one
>year of age from transplacental exposure to PCBs and DDE. Higher
>transplacental exposure to PCBs was associated with lower psychomotor
>scores at both six and twelve months of age. The key finding here was
>that exposure to either chemical through breastfeeding was unrelated to
>the Bayley Scales of Infant Development test scores. No adverse effects
>on growth or occurrence of illnesses in the first year of life have been
>attributed to the presence of these chemicals in human milk.
>
>In 1991 three more studies in this series were published:
>
>A study published in the Annals of Epidemiology looked at "Child
>Development at Eighteen to Twenty-four Months" versus PCBs and DDE
>exposure. The trend toward lower psychomotor scores on the Bayley tests
>was still present and determined to still be due to transplacental
>exposure to the chemicals. There was no evidence of any effect from the
>larger but later exposure through breast milk, but at that time, Rogan
>expressed concern that such effects might show up as the children reached
>an older age.
>
>Another study in the Journal of Pediatrics followed up the children, now
>age five-and-a-half to ten-and-a-half years, with the McCarthy Scales of
>Children's Abilities and by checking report cards, when available, to see
>if the psychomotor deficit through two years of age, due to
>transplacental but not breastfeeding exposure to PCBs, was still present.
>The deficits seen at two years on the Bayley Scales of Infant Development
>were no longer apparent.
>
>The third 1991 study in Regulatory Toxicology and Pharmacology was
>particularly important. Rogan and colleagues developed various types of
>mathematical analyses to answer concerns about possible lifetime cancer
>risks from human milk exposure to chemical contaminants. The pesticides
>considered were DDT, chlordane, heptachlor, dieldrin and their
>metabolites, and industrial compounds or byproducts, such as PCBs and
>dioxins.
>
>An initial statement was made in that article that the contaminant levels
>in human milk would prevent its sale as a commercial food for infants,
>based on current standards. This type of statement is made quite casually
>from time to time, with no regard for the concern it causes breastfeeding
>mothers.
>
>Regulatory standards have been set by the World Health Organization and
>US Food and Drug Administration to attempt to control the levels of
>contaminants in foods. Current "allowable" levels have been set low to
>prevent toxicity in adults from exposure over a lifetime. In reality,
>there is a range in concentration of the chemicals, sometimes 100 to 1000
>times higher, over which no adverse reactions have been reported. It is
>also important to remember that human milk constitutes only one very
>limited route and time of exposure to contaminants over an individual's
>lifetime. In addition, the rapidly growing infant is gaining body fat,
>and thus a place to effectively store contaminants, during the time it is
>receiving human milk. What this means is that even though human milk may
>contain higher levels of contaminants than some commercial food stuffs,
>there are substantial, built-in safety margins.
>
>Rogan's analytical methods viewed risk from:
>
>* EXPOSURE to these chemicals in human milk over the duration of
>breastfeeding,
>
>* CARCINOGENICITY of the various chemicals,
>
>* LIFE EXPECTANCY based on death rates from cancer attributable to the
>chemicals,
>
>* POSTNEONATAL MORTALITY differences between breastfed and bottle-fed
>children, including the well-documented two-and-a-half times increased
>risk of death in the first two years of life from not being breastfed,
>
>* CHANGE IN LIFE EXPECTANCY between breastfed and bottle-fed children,
>assuming that breastfed children have excess cancer risk from the
>contaminants.
>
>The results were quite striking. Estimated loss of life expectancy from
>cancer from human milk exposure to the contaminants studied was less than
>three days; in contrast, the decrease in life expectancy from excess
>postneonatal mortality in infants not breastfed compared to the increase
>in life expectancy in breastfed infants is about seventy days. There was
>not only no advantage to avoiding breastfeeding, there was a
>disadvantage. Breastfed children, even those at the extreme doses of
>contaminants considered to be in human milk, had a net lower risk of
>death and longer life expectancy.
>
>Rogan concluded that at current levels, the estimated cancer risks
>associated with contaminants in breast milk do not outweigh the benefits
>of breastfeeding. Because of these results, he also questioned the
>usefulness of testing human milk for contaminants in the general
>population, although he felt that individual women facing occupational or
>accidental exposure from PCBs in particular might consider testing.
>
>In 1992 in NeuroToxicology, Rogan once again reviewed what had been
>learned in the preceding years about the neurotoxicology of PCBs and
>related compounds. Information about breastfed children concluded that
>despite the presence of PCBs in breast milk, no association between
>breast milk exposure and any measured outcome has been seen other than
>lower activity levels at four years among long-term breastfed children at
>the highest PCB levels.
>
>And finally, in 1993 in Early Human Development Rogan examined
>breastfeeding and cognitive development in the children he had followed
>for so long. What he discovered was that the breastfed children, even
>though they had received higher contaminant loads through human milk than
>the children who had been bottle-fed from birth, scored significantly
>higher on the Bayley and McCarthy mental and psychomotor development
>tests (at all time points from two years through five years) and had
>higher English grades on report cards from grade three or higher. There
>were also trends toward higher scores with increasing length of
>breastfeeding. Rogan concludes that breastfeeding, even with known
>contaminants in human milk, offers the potential for enhancing the
>children's development within the population at no risk and little cost.
>
>So, in answer to one of my original questions--can breastfeeding still be
>recommended for infants in this contaminated world.? Yes, and the
>research is there to confirm that answer.
>
>But what about the contaminants found in the infant feeding alternative,
>commercial infant formula?
>
>The Rogan series of studies cited earlier also analyzed cow's milk and
>infant formula that was being fed to infants and children not receiving
>human milk. No overall significant levels of pesticides and
>organochlorine contaminants were found, although individual samples may
>be higher.
>
>Even though processing standards and contaminant limits have been set in
>the USA, remember that cows are part of the contaminated environment,
>eating grasses, grains, and other feed potentially treated with
>pesticides and drinking water potentially contaminated with a variety of
>chemicals. Dairy cattle are also treated with a variety of drugs,
>including antibiotics, and these can find their way into the milk supply
>as well as potentially into infant formulas which are predominantly cow's
>milk-based.
>
>One set of compounds not yet discussed are the heavy metals, such as
>lead, cadmium, and mercury. The heavy metals bind more readily to human
>milk proteins as opposed to the previously described pesticides and
>organochlorines which bind to lipids.
>
>In general population exposure, lead levels in human milk are normally
>lower than the lead levels in milk-based infant formulas. This is
>especially true when concentrated infant formulas are mixed with water
>containing high lead levels or packaged in lead-soldered cans. There are
>generally higher blood lead levels in formula-fed infants than breastfed
>infants, too. The February 1994 issue of Pediatrics takes an extensive
>look at the lead crisis in infants in general, including the continuing
>controversy over the new lower blood lead concentration limit recently set.
>
>Cadmium levels in breast milk are about the same as in cow's milk. Please
>note, however, that cadmium and DDT levels are higher in the breast milk
>of smokers.
>
>Mercury levels typically are lower in human milk than those of lead and
>cadmium. The highest levels have been found in the milk of fish eaters,
>particularly sport fish. Concern is also raised from time to time about
>the contribution of mercury to human milk from silver amalgam dental
>fillings. This bears research investigation.
>
>Much of the preceding information comes from a highly respected reference
>text entitled Chemical Compounds in Human Milk, edited by two
>world-renowned researchers in the field, Allan A. Jensen of the Danish
>Institute of Technology, Department of Environmental Technology, and
>Stuart A. Slorach of the Food Research Department at the Swedish National
>Food Administration. This text reviews the global contaminant picture and
>its impact on human milk to 1991 in terms of general population versus
>occupational exposure.
>
>Other facts of interest from this book include the following:
>
>Dietary intake of contaminants during lactation is not a significant
>source of contamination in breast milk; the contaminants come from the
>mobilization of adipose tissue into the lipids in human milk. During
>pregnancy, however, dietary intake may significantly affect maternal
>contaminant levels because of an increase in adipose tissue in
>conjunction with weight gain, as well as development of key organ systems
>in the fetus itself.
>
>Contaminant levels are also dependent on personal exposure from a woman's
>location in the environment. There are higher levels of persistent
>organochlorines in women living in coastal regions, presumably from
>eating more readily available fish. However, women who consume great
>quantities of beef and dairy products should also be aware of concerns.
>
>There are lower levels of DDT and DDE in the milk of vegetarian mothers,
>but stable PCB levels indicate that contaminant sources other than food
>are involved, for example air pollution outdoors and indoors.
>
>The following quotation sums up the risk-benefit considerations as
>summarized in this authoritative text:
>
>Reports in the mass media about the presence of toxic chemicals in breast
>milk often alarm mothers, who wonder whether they should get their milk
>analyzed and, if the levels are relatively high, stop breastfeeding.
>Virtually all national and international expert committees have hitherto
>concluded--on the basis of available information--that the benefits of
>breastfeeding outweigh the possible risks from chemical contaminants
>present in human milk at normal levels. There is little point in
>investigating milk from individual concerned mothers, unless there are
>indications of abnormally heavy exposure, for example, at the workplace
>or due to poisoning incidents.
>
>References
>
>Gladen, B. C. et al. Development after exposure to dichloroethene
>polychlorinated biphenyls and dichlorodiphenyl transplacentally and
>through human milk. J Pediatr 1988; 113(6):991 -95.
>
>Gladen, B. C. and W. J. Rogan. Effects of perinatal polychlorinated
>biphenyls and dichlorodiphenyl dichloroethene on later development.
>JPediatr1991; 119(1pt1):58-63.
>
>Jensen, A. A. and S. A. Slorach, eds. Chemical Contaminants in Human Milk
>1991; Boca Raton, Florida: CRC Press, Inc.
>
>Rogan, W. J. et al. Pollutants in breast milk. N Engl J Med 1980;
>302(26):1450-53.
>
>Rogan, W. J. et al. Polychlorinated biphenyls (PCBs) and
>dichlorodiphenhyl dichloroethene (DDE) in human milk: effects of maternal
>factors and previous lactation. AJPH 1986; 76(2):172-77.
>
>Rogan, W. J. et al. Neonatal effects of transplacental exposure to PCBs
>and DDE. J Pediatr 1986; 109(2):335-41.
>
>Rogan W. J. et al. Polychlorinated biphenyls (PCBs) and dichlorodiphenyl
>dichloroethene (DDE) in human milk: effects on growth, morbidity, and
>duration of lactation. AJPH 1987: 77(10) :1294-97.
>
>Rogan, W. J. and B. C. Gladen. PCBs, DDE, and child development at 18 and
>24 months. Ann Epidemiol 1991; 1(5):407-13.
>
>Rogan, W. J. et al. Should the presence of carcinogens in breast milk
>discourage breast feeding? Reg Toxicol Pharmacol 1991; 13:228-40.
>
>Rogan, W. J. and B. C. Gladen, Neurotoxicology of PCBs and related
>compounds. NeuroToxicology 1992; 13:27-36.
>
>Rogan, W. J. and B. C. Gladen. Breast-feeding and cognitive development.
>Early Human Dev 1993; 31:181-93.
>
>Wolff, M. S. et al. Blood levels of organochlorine residues and risk of
>breast cancer. JNCI 1993: 85(5):648-52.
>
>
>Betty Crase, BA, IBCLC, has been an LLL Leader for 17 years and is the
>manager of LLLI's Breastfeeding Reference Library & Database. This
>article features some of the highlights from a presentation she gave at
>an environmental conference entitled "Pesticides: Alternatives and
>Solutions," held in February 1994 in Chicago, Illinois, USA, cosponsored
>by a number of national environmental organizations.
>
>["Minimizing Contaminant Risks During Pregnancy and Lactation" ran along
>with this article; it is also available on the TLC LEAVEN pages.]
>
>
----------------------------------------------------------------------------
-------
Katherine A. Dettwyler, Ph.D.                         email: [log in to unmask]
Anthropology Department                               phone: (409) 845-5256
Texas A&M University                                    fax: (409) 845-4070
College Station, TX  77843-4352
http://www.prairienet.org/laleche/dettwyler.html

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