Toxins in human milk

In The Netherlands, where I live, very often this issue comes up in the media. Many mothers are concerned about a possible toxidity of their milk, and formula producers use this issue in their literature about breastfeeding and artificial baby milk to discourage mothers to breastfeed their babies.

However, unlike many research done on this issue, there has never been found any evidence that breastfeeding isn't the preferred way of feeding anymore. The risks of feeding a baby at breastmilk far outreaches the risks of toxins in human milk, if there is any at all.

Annelies Bon explains the situation and comes up with a reference list with literature about toxins in human milk.

Influence of the toxins in human milk on the baby

Till short there has never been found any influence of the toxins in human milk on the baby, but recently in a Dutch research there was found some influence: In babies who received high doses of dioxin during their stay in the womb and through human milk, breastfeeding counteracted some of the positive effects on the motoric and neorological skills of the breastfed baby. In other words: breastfed babies who received high levels of toxins, fell back to the level of formulafed infants. But, one of the researchers said in a interview in the Volkskrant (August 8, 1996): "Breastfeeding restrains the negative effects on babies from dioxin exposure during the pregnancy". Most influence of the dioxins is during the pregnancy. The toxins pass through the placenta and have impact on mental and psychomotoric development of children.

Advice of the Dutch Health Council

In The Netherlands this subject has got a lot of publicity since the seventies. Several times newspapers published alarming articles about the high levels of toxins in breastmilk. The Dutch government decided to research breastmilk and give a breastfeeding advice. The latest report of the Health Council of the Netherlands (a governmental institution) was in 1996:

"Most adults in the Netherlands are exposed to approximately two picogrammes of toxic equivalents of dioxin-like substances per kilogramme of body weight per day. In general, it may be stated that in excess of 90% of human exposure to PCDDs, PCDFs and dioxin-like PCBs derives from the consumption of animal fats, of which 50% are contained in milk and milk products. Infants are exposed to these substances before birth as well as through the maternal milk. Their exposure through the maternal milk, expressed per kilogramme of body weight, may thus be substantially higher than that of adults. These exposure figures may be compared to the recommended exposure limit proposed by the committee.

This leads to the conclusion that the possibility that the ingestion of dioxin-like compounds causes adverse health effects in the Dutch population cannot be excluded with reasonable certainty.
The committee believes that it is supported in this conclusion by the correspondences between the degree of prenatal and postnatal exposure to dioxin-like substances and differences in development found in studies of infants up to the age of eighteen months. However, the findings of these Dutch studies gave no indication of development in infants outside what is considered to be the normal range. According to the committee the best way to reduce the exposure of infants is to reduce the life-time exposure of mothers, in fact the exposure of the whole population.
Limitation of breastfeeding is not the right way. It was already known and recent studies confirmed that breast feeding has a positive effect on the development of infants compared to formulafeeding. There is no reason to limit the freedom of parents to choose between breastfeeding and formulafeeding for their infant." By: Health Council of the Netherlands, committee on risk evaluation of substances/dioxins.
Read more: Dioxins, polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls Rijswijk: Health Council of the Netherlands, 1996; publication no. 1996/10.

"However, the committee is of the opinion, in the basis of general findings relating to the sensitivity of organisms at different moments in their development, that prenatal exposure is the more critical phase." (p. 78, same report as the above).

Conclusion

Exposure of nurslings to dioxines and dioxine alikes through breastfeeding is relatively high, and therefor a subject of research. Much research has been done, also a big Dutch research. This latest research shows again the positive influence of breastfeeding on the psychomotorological and neuromotorological development of babies. The few negative effects on the development of nurslings are contributed to the higher dioxins levels during the pregnancy and not to exposure through breastfeeding from the newborn. Restriction of breastfeeding certainly isn't recommended to lessen the effects of dioxins on nurslings or in later life.

Press release from La Leche League International

This press release is reprinted with the permission of La Leche League International.
[Delivered 21 April 1997 By Trisha Noack, Director of Public Relations, LLLI]

Today Greenpeace focuses our attention on the role of polyvinyl chloride, or PVC, in producing harmful contaminants such as dioxin which appear in human milk. While we acknowledge this message, La Leche League International reminds everyone that research indicates that even in a contaminated world, human milk is still best for babies. La Leche League International helps mothers worldwide to breastfeed through mother-to-mother support, information and education. Part of our mission is to promote better understanding of breastfeeding as an important element in the healthy development of the baby and mother.

Both human milk and the unique relationship between a breastfeeding baby and nursing mother offer significant advantages to mothers and babies. Other feeding methods draw raw materials from the same environment as human milk and are likely to contain the same contaminants. The production and disposal of artificial baby milk products add to our environmental problems by consuming energy and producing waste. Human milk contains dioxins only because it is the product of a contaminated world. Fortunately, human milk also helps children combat the effects of pollution while it has no negative impact on the environment. Indeed, the benefits of human milk may prove to be essential to compensate for and outweigh toxic effects from the environment.

La Leche League International acknowledges that human milk contains suspect compounds, reflecting general environmental contaminant levels. We urge society to examine the role of such substances as PVC in contributing to this condition. While science and industry search for a way to resolve this problem, we urge health care providers and parents to examine the research which overwhelmingly indicates that breastfeeding is still the very best start for our babies.

We call the attention of environmentalists to the message of the World Alliance for Breastfeeding Action, of which La Leche League is a charter member. The theme for World Breastfeeding Week 1997, August 1-7, is Breastfeeding: Nature's Way. We ask the help of all environmentalists in supporting breastfeeding as the optimal form of infant feeding while the use of damaging substances is brought under control. Human milk is a valuable natural resource that should be promoted and protected. Environmentalists and breastfeeding support groups alike have a common interest in promoting breastfeeding, the healthiest and most ecologically sound way to nurture our babies.

Letter from Doraine Bailey to Mother Jones Magazine, written Februari 1998

Dear Mother Jones Magazine,

Thank you for your interesting and thought-provoking interview by Marilyn Berlin Snell. It is a good reminder that progress is not without price, including the endangerment of our inheritors, our children.
In response to the article's discussion on the environmental risk factors associated with breastfeeding, I believe Ms. Snell and your readers would appreciate some additional information.

• Babies who are breastfed have lower risk for illness and death from contaminants and toxins in the environment than babies who are not breastfed
• Breastfed babies need no additional food or drink for about the first 6 months of life, reducing their exposure to contaminated or low-quality water or food and unsanitary food preparation areas
• Breastmilk rarely has environmental contaminants compared with industrially-produced baby foods which can fall victim to contamination (Dusdieker L, et al.)
• Studies show that neurological damage from fetal exposure to toxins is mitigated in direct proportion to the amount of breast milk in an infant's diet

The World Health Organization has carefully examined environmental toxins and the risk to chidren. They concluded that the advantages of breastmilk far outweigh any possible risks and recommend breastfeeding as preferable to any alternative.
Occasionally, reports will appear discussing the levels of contaminants in mother's milk, scaring women away from breastfeeding. The baby food industry has capitalized on mothers' insecurities, exaggerating the qualities of artificial milks and minimizing their known and proven risks. Here are some things to keep in mind

• Breastmilk is an easy source of human body fat for measuring the amount of toxins carried by a community's residents. Health authorities are not usually interested in the toxing levels in milk itself; studies are not typically done becaue of suspicions about ill-health of breastfed babies (Sim and McNeil)
• Other feeding methods draw raw materials from the same environment as human milk and are likely to contain the same environmental contaminants, as well as other possible contaminants resulting from the manufacturing process
• No company can continuously monitor its milk for every possible contaminant. Chemicals, metals, and organic compounds are never discovered if they are never sought
• Thirteen percent of infants studied were exposed to lead levels in excess of World Health Organization guidelines through artificial baby milk feedings (Watt GCM, Britton A, et al)
• Methemoglobinemia (Blue baby syndrome) arises most frequently from drinking water contaminated with nitrates from agricultural fertilizers. Over 12 million people in the U.S. drink water from public water systems where nitrate levels exceed standards. Such water systems are also used by artificial baby milk and infant food manufacturers. Infants whose food sources are reconstituted with nitrate-rich tap water (artificial baby milk, juice) face an exposure 80 times greater than infants not exposed to such water. Nitrates are not passed through breastmilk(Craun et al.)

Of course, the irony of the article is that any alternative to human milk for infant feeding perpetuates the very environmental contamination she condemns. The manufacture of artificial baby milks contribute to environmental pollution in many ways. There is a short (and incomplete) list:

• Cow: methane, rangeland soil compaction and degradation, fecal runoff into soils and water supplies, feed consumption, de-forestation to create more range or agricultural land
• Animal Feed: Carbon monoxide (CO) from growing, shipping and processing the crop; pesticide and herbicide runoff into water and soil; soil erosion, depending on farming practices. May also include animal components (beef, chicken, fish) which may contain toxic contaminants (PCBs, BSE virus, etc.)
• Milk Collection: CO exhausts from power plants for milking machines and refrigeration, and from transportation to processing center
• Milk Processing: CO exhaust from power plants for electricity and from processing centers for processing milk; chemicals from equipment cleaning; water wastes; wastes from processing and transporting ingredients
• Milk Packaging: CO exhaust from manufacture and shipping of packaging materials - steel, plastic, paper, cardboard; chemicals from label printing; wastes from individual product as well as group packaging
• Product Transportation: CO exhaust from transport to distribution centers, warehouses, and individual retailers, sometimes international
• Product Waste Disposal: landfill, ocean dumping, or incineration; water and ground contamination; non-bio degradable, non-recyclable materials (plastics)

There are no easy answers. However, continuing campaigns to phase out PCBs and other persistent organic pollutants have shown promise. Protecting, promoting and supporting breastfeeding is the best way to support such campaigns as well as building the healthiest children possible.

In 1997, the World Alliance for Breastfeeding Action (WABA) declared the annual theme for World Breastfeeding Week as "Breastfeeding: Nature's Way." WABA and the International Lactation Consultant Association both have excellent materials examining the environmental impact of infant feeding. Such materials may be of great interest and value to your readers. The organisations may be contacted as noted below.
"If breastmilk becomes too contaminated to use, then it is likely that our chances of having healthy children, or even being able to reproduce at all, will be in jeopardy." [Gabrielle Palmer]

Sincerely,
Doraine Bailey, MA
Breastfeeding Promotion and Support Specialist [1]

References and readings

• Sitarz, D (ed.) Agenda 21:The Earth Summit Strategy to Save our Planet
• Naar, Jon. Design for a Livable Planet: How you can help clean up the environment. New York: Harper & Row, 1990
• Craun et al. Methaemoglobin levels in young children consuming high nitrate well water in the U.S. Intl J Epidemiol 10:309-317, 1981
• Dusdieker L, et al. Nitrate in baby foods. Arch Ped Adol Med 148:490-494, 1994
• Goldman, Benjamin A (1991) The Truth About Where You Live: An atlas for action on toxins and mortality. New York: Random House. (U.S. Data only)
• Palmer, Gabrielle, The Politics of Breastfeeding 2nd edition, London: Pandora Press, 1993
• Radford A. "Breastmilk: A World Resource" WABA Activity Sheet #1. World Alliance for Breastfeeding Action, P.O. Box 1200, 10850 Penang, Malaysia
• Sim MR, McNeil JJ. "Monitoring chemical exposure using breastmilk: a methodological review." Am J. Epidemiol 136:1, 1992
• Watt, GCM, Britton, A, et al. "Is lead in tap water still a public health problem? British Med J 313:979, 1996

Bibliography

• Lead and Mercury in Breast Milk Claudia Gundacker, PhD, Beate Pietschnig, MD, Karl J. Wittmann, PhD, Andreas Lischka, MD, Hans Salzer, MD, Leonhard Hohenauer, MD and Ernst Schuster, PhD. Pediatrics Vol. 110 No. 5 November 2002, pp. 873-878 Conclusions. Neither Hg nor Pb concentrations exceeded critical levels. There are no reports on infants harmed by the intake of milk from unexposed mothers. We conclude that even theoretical risks from current Hg or Pb levels for the breastfed infant of a healthy mother can be ruled out
• Environmental exposure to polychlorinated biphenyls and quality of the home environment: effects on psychodevelopment in early childhood Jens Walkowiak, Jörg-A Wiener, Annemarie Fastabend, Birger Heinzow, Ursula Krämer, Eberhard Schmidt, Hans-J Steingrüber, Sabine Wundram, Gerhard Winneke . The Lancet Volume 358, Number 9293 10 November 2001
• Harris CA, Woolridge MW, Hay AW. , Factors affecting the transfer of organochlorine pesticide residues to breastmilk. Chemosphere 2001 Apr;43(2):243-56. "Existing studies monitoring organochlorine pesticide residues in breastmilk were examined to identify whether common factors determine the extent of transfer of these residues. A structured review of the English language literature was conducted. Papers were reviewed and assessed using a structured protocol. A total of 77 papers were initially identified, 46 of which contained conclusions relating to the factors which may affect the transfer of residues into breastmilk. Owing to the diversity of findings, papers were screened further to include only those in which a minimum of background information relating to selection of mothers and to milk sampling procedures were reported. Only eight papers were deemed to contain adequate information. Age, parity/length of previous lactation, fat mobilisation and the time of sampling were identified as the most likely factors to be considered when assessing transfer of organochlorine pesticide residues into breastmilk. This review highlights the difficulties of assessing trends in breastmilk contaminants where comparable sampling procedures are not used."
• Effects of perinatal PCB and dioxin exposure and early feeding mode on child development C. Lanting
• Environmental exposure to polychlorinated biphenyls (PCBs) and dioxins Consequences for longterm neurological and cognitive development of the child lactation. Boersma ER, Lanting CI . Adv Exp Med Biol 2000;478:271-87. "Despite a higher PCB exposures from breast milk we found at 18 months, 42 months of age, and at 6 years of age a beneficial effect of breast feeding on the quality of movements, in terms of fluency, and on the cognitive development tests." "Human breast milk volume and fat content is adversely affected by the presently encountered PCB levels in W. Europe. Our studies showed evidence that breast feeding counteracts the adverse developmental effects of PCBs and dioxins."
• Effecten van PCB's en dioxines. Marcel Huisman, ISBN 90 3670688 2
• Exposure of populations to dioxins and related compounds Liem AK, Furst P, Rappe C . Food Addit Contam 2000 Apr;17(4):241-59. "Exposure has been shown to have fallen over time in all countries where data are available. Countries that started to implement measures to reduce dioxin emissions in the late 1980s, such as The Netherlands, United Kingdom and Germany, clearly show decreasing PCDD/PCDF and PCB levels in food and consequently a significantly lower dietary intake of these compounds by almost a factor of 2 within the past 7 years."
• Effects of environmental exposure to polychlorinated biphenyls and dioxins on cognitive abilities in Dutch children at 42 months of age, by Patandin, S. et al. Journal of Pediatrics, January 1999, Volume 134, Number 1, pp33-4. Results: After adjustment was done for covariables, maternal PCB was associated with lower scores on the overall cognitive and sequential and simultaneous processing scales of the Kaufman Assessment Battery for Children (all P < .05). The highest exposed group (PCB 3 µg/L) scored 4 points lower on all 3 scales of the K-ABC when compared with the lowest exposed group (PCB < 1.5 µg/L). Both lactational exposure and current exposure to PCBs and dioxins were not related to 42-month cognitive performance. Conclusions: In utero exposure to “background” PCB concentrations is associated with poorer cognitive functioning in preschool children. Children of mothers at the upper end of exposure are especially at risk. Therefore maternal PCB body burden should be reduced, and breast-feeding should not be discouraged
• Dietary Exposure to Polychlorinated Biphenyls and Dioxins from Infancy Until Adulthood: A Comparison Between Breast-feeding, Toddler, and Long-term Exposure by Patandin, S. et al. Environmental Health Perspectives Volume 107, Number 1, January 1999
• Comparisons of Blood Dioxin, Dibenzofuran, and Coplanar PCB Levels in Strict Vegetarians [Vegans] and the General United States Population, A. Schecter and O. Papke, Organohalgen compounds 38 (1998): 179-82
• T. Vartianen et al., PCDD, PCDF, and PCB Concentrations in human milk from two areas of Finland Chemosphere 34(1997): 2571-83. The third-born child was exposed to only 70% of the PCBs and dioxins of the first-born. The 8th, 9th, and 10th children received only 20 percent as much
• Pre- and postnatal exposure to PCBs and dioxins a nd cognitive developement of Dutch children at 3 1/2 years of age, Organohalgen compounds Vol. 34 (1997) by Svati Patandin et al
• Plasma polychlorinated biphenyl levels in Dutch preschool children either breast-fed or formula-fed during infancy by Patandin, S., et al. American Journal of Public Health 87(October), 1997: 1711
• Chemical Analysis, exposure and risk assessment by A.K.D. Liem and R.M.C. Theelen, Oct 1997, ISBN 90-393-2012-8. Chapter 6. Risk Assessment of Breast-Fed Infants
• Environmental Toxicology and Pharmacology of Human Development, by S. Kacew and G. Lambert, Eds, Taylor and Francis Publ, 1997. Chapter 5 "Transport of Organic Chemicals to Breastmilk: Tetrachloroethene Case Study". "Therefore, in almost all circumstances, breastfeeding is highly advantageous for infant health and well-being despite the presence of chemical contaminants in human milk."
• Committee on Risk Evaluation of Substances/Dioxins. Dioxins. Polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls Rijswijk: Health Council of the Netherlands, 1996; publication no. 1996/10, ISBN: 90-5549-116-0 English summary
• Effects of Polychlorinated Biphenyl/Dioxin Exposure and Feeding Type on Infants' Mental and Psychomotor Development by Corine Koopman-Esseboom, MD, PhD; Nynke Weisglas-Kuperus, MD, PhD; Maria A.J. de Ridder; Cornelis G. van de Paauw; Louis G.M.Th. Tuinstra, MSc; Pieter J.J.Sauer, MD, PhD. Pediatrics Vol.97 No.5 May 1996. Results: Higher in utero exposure to PCB's was associated with lower psychomotor scores at 3 months of age: a doubling of the PCB load resulted in a decrease of 3 points. Breastfed infants scores significantly higher on the psychomotor score at 7 months of age, compared with formula-fed infants. However, when corrected for confounders, the psychomotor score of the 66% highest-exposed breastfed infants (>756 pg total PCB-dioxin toxic equivalent) was negatively influenced by this post-natal exposure to PCB's and dioxins and was comparable to the psychomotor score of formula-fed infants. Breastfed infants also scored higher on the mental scale at 7 months of age in a dose-dependent way. There was no significant influence of the perinatal PCB and dioxin exposure on the mental outcome at 3 and 7 months of age. At 18 months of age neither the mental nor the psychomotor score related to perinatal PCB or dioxin exposure, nor to the duration of breastfeeding. Conclusions: Prenatal PCB exposure has a small negative effect on the psychomotor score at 3 months of age. PCB and dioxin exposure through breastfeeding has an adverse effect on the psychomotor outcome at 7 months of age. The mental outcome at 7 months of age is positively influenced by breastfeeding per se; the perinatal exposure to PCB's and dioxins does not influence this outcome. At 18 months of age the development is affected neither by PCB's and dioxin exposure nor by feeding type
• Borstvoeding in een vervuild milieu, E.Rudy Boersma e.a., TW July/August 1996, p21-30. Conclusions: see the above article. And: there is a strong correlation between the (longterm) consumption of fat dairy products and high levels of PCB's and dioxines. However, the dioxin and PCB levels in the fat of the mother's body is the result of a longlife exposure. Restriction of consumption of dairy products during pregnancy and lactation will not lead to lower levels of dioxin and PCB levels in her human milk. Look at the University of Groningen for a description of this research project.
• Polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated diphenyls, report of the Health Council of the Netherlands: Committee on the Risk Evaluations of Substances; no. 1996/10E, Rijswijk, August 6, 1996; ISBN 90-5549-115-2
• Total and Inorganic Mercury in Breast Milk and Blood in Relation to fish consumption and amalgan fillings in Lactating women. Ageneta Oskarsson e.a. Archives of Environmental Healt, Vol 114, no.2, 1996, p224-6
• DDE and Insufficient Breast milk. Chessa Lutter and Rafael Perez-Escamilla, Am J of Public Health, Vol.86, No.6, 1996, p.887-8
• DDE and Shortened Duration of Lactation in a Northern Mexican Town. Beth.C. Gladen and Walter J.Rogan Am J of Public Health, Vol.85, No.4, 1995, p.504-8. Dr. Rogan's main research focus has been the effect of pollutant chemicals on the growth and development of children. He has been involved with three major studies. The first is a cohort study of North Carolina children exposed to background levels of PCBs and DDT. These children were born between 1978 and 1982, and were followed through puberty. Although the primary hypothesis of this study was that PCBs and DDT (as DDE) in breast milk might produce toxicity in nurslings, Rogan and his co-investigator, Beth Gladen (Statistics Branch, NIEHS), showed that transplacental but not lactational exposure to PCBs produced small but persistent delays in motor development detectable from birth to age 2 years. They also showed that DDE at higher levels was associated with markedly earlier weaning, replicated that finding in Mexico, and speculated that this might be because DDE is a weak estrogen
• Organochlorine compound residues in human milk in the United Kingdom 1989-1991. S.Dwarka e.a. Human & Experimental Toxicology, 14, 1995, p.451-5
• Milestone Development in Infants Exposed to Methylmercury from Human Milk. Philippe Grandjean e.a. Neuro Toxicology, 16(1), 1995, p.27-34. ABSTRACT by Chris Hafner-Eaton, PhD, MPH, CHES Appeared in: Breastfeeding Abstracts winter 96/97, publication of LLLI Purpose: Although human milk has been repeatedly demonstrated to enhance mental and psychomotor development in children, the neurotoxic effects of environmental pollutants transferred via breastfeeding were unclear and undocumented. Previous research focused on prenatal exposures and failed to control for breastfeeding status or duration; although studies of polychlorinated biphenyls (PCBs) have included breastfeeding with the results being protective in spite of PCB transfer through the breastmilk. This study investigated the significance of methylmercury exposure, a known neurotoxicant, from human milk in Faroese infants. Method: Granjean, Weihe, and White followed a birth cohort from consecutive deliveries during a 21 month period in 1986-1987 at three hospitals in the Faoroe Islands where high consumption of contaminated seafood was prevalent. Questionnaire data, and samples of umbilical cord blood and maternal hair for mercury analysis were obtained from 1022 singleton births (75.1% of all deliveries). Midwives collected questionnaire data regarding pregnancy course, dietary habits (frequency of fish and pilot whale), and the use of alcohol and tobacco. Additional information obtained from hospital charts and midwife recordings included parity, course of the parturition, birth weight and length and other relevant information. Following the birth, home visits by nurses provided data for the month (5-12 months) that developmental milestones were achieved for sitting without support, creeping, and getting to a standing position with support. The duration of nursing without supplements and age at weaning were also scored in months. Nonparametric statistical methods were used because the data did not fit a normal Gaussian distribution necessary. Correlations were deemed significant using Spearman's correlation coefficient, and differences between groups by the Mann-Whitney U-test. Results: Only 15 infants were not nursed at all, with 97.4% breastfeeding for at least 1 month. One hundred (17.2%) were breastfeed for 2 months or less, and 143 (24.5%) were breastfed for 3 months or less. Human milk was the sole source of nutrition for a median of 4 months, and weaning followed at a median age of 7 months. The age at which the child reached a developmental milestone was not associated with indices of prenatal mercury exposure, i.e., the mercury concentrations in umbilical cord blood and in maternal hair (p> 0.4 by Spearman's). The same lack of correlation existed for infants who were not breastfed at all or only briefly. However, milestone development was associated with the child's mercury burden at 12 months of age. The results show a paradoxical relationship where the longer a child was breastfed, the higher the child's hair mercury concentration, and the earlier the child reached the developmental milestones, i.e., indicating an advantage associated with breastfeeding. Even among those breastfed for at least 3 or 4 months, early milestone development was clearly associated with the child's hair-mercury concentration. These correlations were in an unexpected direction for all three milestones. Other potential confounders exhibited statistically significant correlations with breastfeeding duration: smoking (median of 8 months for non-smokers vs. 5 months for smokers); increasing maternal age; marital status (6 months for unmarried vs. 8 months for married mothers); and low birthweigth. These parameters were not associated with maternal mercury exposure. Major predictors of maternal mercury exposure included seafood consumption, parity and alcohol intake, but these were not related to the duration of breastfeeding. Only low birth weight was both a significant predictor of length of breastfeeding (briefer) and delayed milestone development. advantage with regard to developmental milestone attainment in infants, despite documented neurotoxic methylmercury transfer via breastmilk. While the study cohort was not a representative sample, selection factors (e.g., lack of a district health nurse or reluctance to accept nurse's visits) did not appear to affect the tendencies observed. There appears to be beneficial effects associated with breastfeeding such that the neurotoxic effects on milestone attainment are overruled or compensated. Had exposure to mercury through milk caused neurotoxic effects in this study, the duration of breastfeeding would have acted as a predictor for neurobehavioral delays. Clearly, three milestone measurements are limited in their predictive power of subtle forms of neurotoxicity and time of neurobehavioral assessment is also important. Thus, we should not assume that methylmercury from seafood is not a neurotoxicant
• Fish PCB concentration and consumption patterns among Mohawk women at Akwesasne. Edward F. Fitzgerald e.a. J of Exp Anal Environm Epidemiol, Vol.5, no.1, 1995, p.1-19
• "Occupational" exposure of Infants to toxic chemicals via breastmilk. Janusz Z. Byczkowski e.a. Nutrition, Vol.10 No.1, 1994, p43-8
• Organochlorine Pesticide Residues in Human Milk in Kayseri. H.Basri üstünbas e.a. Human & Experimental Toxoicology, 13, 1994, p.229-302
• Polychlorinated Biphenyls (PCBs) in the UK population: estimated intake, exposure and body burden. R. Duarte-Davidson and K.C.Jones. The Science of the Total Environment, 151, 1994, p.131-52
• Lead in breast milk: Should mothers be routineously screened? Laurie Tellier and Richard A. Aronson, Wisconsin Medical Journal, june 1994, p.257-8
• Mono-Ortho- and Non-Ortho-Substituted Polychlorinated Biphenyls in Human Milk from Mohawk and Control Women: Effects of Maternal Factors and Previous Lactation. C.S.Hong e.a. Arch Environm Contamination & Toxicology, 27, 1994, p.431-7
• Breast-feeding in a polluted world: uncertain risks, clear benefits. John W.Frank and Jack Newman. Can Med Assoc J. 149(1), July 1993, p.33-7
• Pesticides and polychlorinated biphenyl residues in human breast lipids and their relation to breast cancer. Falck,Jr, F et al. Arch Env Hlth 1992; 47(2): 143-46
• Toxicological index and the presence in the workplace of chemical hazards for workers who breastfeed infants. Giroux D, Lapointe G, Baril M. American Industrial Hygiene Association Journal 1992; 53(7):471-4
• Toxicological index and the presence in the workplace of chemical hazards for workers who breastfeed infants, Giroux D, Lapointe G, Baril M. American Industrial Hygiene Association Journal 1992; 53(7):471-4
• Rogan WJ Blanton PJ, Portier CJ, Stallard E. Should the presence of carcinogens in breast milk discourage breast feeding? Regulatory toxicology and pharmacology 13, 228-240; 1991 Abstract: Pollutant chemicals are commonly found in human milk at levels that would prevent its sale as a commercial food for infants. The chemicals found most commonly are dichlorodiphenyldichloroethene, polychlorinated biphenyls, dieldrin, chlordane, heptachlor, and polychlorinated dibenzodioxins. In general, the regulatory levels for these chemicals have been set to prevent cancer in adult humans from lifetime exposure. We compared lives saved in the postneonatal period by breast feeding to the estimated excess cancer deaths attributable to the contaminants in breast milk. The results of this analysis suggest that only extreme levels of contaminants in breast milk represent more of a hazard than failure to breast feed, but clinical considerations in individual cases might override this conclusion. Our analysis depends on assumptions about how the chemicals might cause cancer in humans and on whether breast feeding prevents some post-neonatal mortality. Noncarcinogenic hazards from chemical exposure, other hazards from breast feeding such as transmission of viruses, and benefits of breast feeding other than reduction in mortality were not considered
• Effects of perinatal Polychlorinated Biphenyls and dichlorodiphenyl dichloroethene on later development. Beth C. Gladen and Walter J. Rogan, The Journal of Pediatrics, vol.119, nr.1, July 1991, p58-63
• PCB's, DDE, and Child Development at 18 and 24 Months. Walter J. Rogan and Beth C. Gladen. Annual Epidemiology, vol 1, No 5, august 1991, p.407-13
• Jensen AA, Slorach SA. Chemical Contaminants in Human Milk. CRC Press Inc: Boca Raton, 1991. Reviews Booknews, Inc. , 06/01/91 "A global review of the contamination of human milk, providing data on levels of chemical contaminants and covering geographical variations and time trends in levels. Includes discussion of the extent and benefits of breast-feeding, the process involved in the transfer of chemicals into breast milk, the analytical methodology used in human milk studies, occupational chemicals found in human milk, the intake of toxic chemicals by breast-fed infants compared with intakes from other foodstuffs, and official limit values."
• Effects of perinatal polychlorinated biphenyls and dichlorodiphenyl dichloroethene transplacentally and through human milk. Gladen B.C. e.a. The Journal of Pediatrics, 1988, 113, p.991-995
• Jacobson J, Fein GG, Jacobson SW, Schwartz PM, Dowler JK. The transfer of polychlorinated biphenyls and polybrominated biphenyls across the human placenta and into maternal milk. AJPH 74:378-379, 1984
• Jensen AA. Chemical Contaminants in Human Milk. Residue Rev 1983; 89: 1-128
• Wickizer TM, Brilliant LB. Testing for polychlorinated biphenyls in human milk. Pediatrics 68:411-415, 1981

Links to other sites about toxins

• Healthy milk, healthy baby chemical pollution and mother's milk Natural resources and defense council
• Drugs and Toxic Chemicals in Breast Milk by Dr. Janusz Z. Byczkowski.
• Arbo-regels, o.a. over blootstelling aan chemische stoffen
• Sources of dioxins in several European countries
• Basic information about dioxin, and recommendations regarding dioxin in diet
• Toxicity of Dioxins at environmental levels
• Dioxins and their effects on human health WHO Fact Sheet No 225 June 1999
• Guideline Statement on Breastfeeding and Dioxins IBFAN Guideline December 20th, 2000
• Contamination with dioxin of some Belgium foor products from European centre for environment and health (WHO)
• Breastfeeding and lead The journal of the LEAD Group Inc.
• Cut pollution - not breastfeeding Baby Milk Action, reaction on the report Chemical Trespass: A Toxic Legacy published recently by the World Wildlife Fund
• Q&A from Environmental Protection Agency, US
• Minimizing contaminant risks during pregnancy and lactation Betty Crase, from LEAVEN, Vol. 30 No. 3, May-June 1994, p. 37
• Breastfeeding and environmental contaminants
• Toxins in formula is suspected to cause Violent Crime
• Hormone Disrupting Chemicals These pages provide an introduction to the effects of hormone disrupting chemicals on man and the environment. Other terms used to describe these chemicals include xenoestrogens, oestrogenic (estrogenic), hormone mimicking and endocrine disrupting chemicals. The chemicals involved include pesticides such as DDT, lindane and atrazine, the food packaging chemicals, phthalates and bisphenol A, alkylphenol ethoxylate detergents and the chemical industry by-products, dioxins. These pages are aimed at anyone interested in the subject, and include references to other research and reviews for those interested in investigating the field further. The pages focus particularly on those chemicals which are not organochlorines, but some information is also provided on organochlorines

Extra information about the dioxin crisis in Belgium in 1999

• Short report of the standing veterinary committee (99/21) held in Brussels on 16 july 1999

[1] Writer of the letter

Doraine Bailey, MA
Breastfeeding Promotion and Support Specialist
International Lactation Consultant Association (ILCA)
4101 Lake Boone Trail, Suite 201
Raleigh, NC 27607 USA

World Alliance for Breastfeeding Action (WABA)
World Breastfeeding Week Coordination
Av.Beira Mar, 3661 Lj.18
Casa Caiada - Olinda - PE
CEP 53130-540 - Brazil