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More than 350 man-made contaminants have been found in the breast milk of mothers, including some 87 dioxin and dioxin-like compounds, and some 190 volatile compounds. Even so, WWF insists that it is still better for babies to be breast-fed than not.

The report, Chemical Trespass: A Toxic Legacy, reviews a range of scientific research now available on contaminants in breast milk. WWF believes that governments and industry must take urgent action now to address the toxic legacy being passed on to future generations.

Gwynne Lyons, author of the report and Scientific Consultant on Toxics for WWF-UK, said breast-fed babies in the UK, and many other industrialised countries, were still receiving far in excess of the WHO's recommendations for daily intakes of dioxins and dioxin-like substances.

"Sadly we are only getting part of the picture. The full range of contaminants in UK breast milk is unknown because past surveys have focused on a limited range of substances, many of which have been banned for several years," Gwynne Lyons said.

Elizabeth Salter, Head of WWF's Toxic Programme, hopes the report will encourage governments and industry to take real action to end this fateful legacy of "hand-me-down" poisons. But she cautioned against those who would use the report to discourage breast feeding.

"WWF strongly supports breast feeding as the best option for new mothers and their babies" she declared. "It provides immunological advantages, important nutrients and encourages bonding between mother and child. These positive factors outweigh the negatives of the toxic chemicals in breast milk.

"However, WWF believes mothers have the right to breast feed with confidence, knowing that the toxicity levels in their breast milk are as low as realistically possible, and certainly below WHO limits. This report clearly indicates that reducing the exposure of the unborn and new born infant to pollutants is now a major challenge for modern society."

WWF is calling on governments in Europe and throughout the world to take swift action to eliminate the use and production of persistent chemicals. The British government has committed some additional funding to investigate whether other contaminants, such as bisphenol A, polyaromatic hydrocarbons (PAHs) and various phthalates, are present in breast milk. However, WWF believes an even more extended survey of UK human contamination is needed.

Case studies on the effects of "hand-me-down" poisons
An ever-increasing scientific database demonstrates that the exposure of wildlife and humans to toxic chemicals is a global problem that needs action now. WWF is particularly concerned about the impact of endocrine or hormone disrupting chemicals (EDCs) on the environment and human health, and has also campaigned extensively for the ban of a range of persistent organic pollutants (POPs). The following case studies are a snap shot of the "accidental" evidence of human health impacts now being seen worldwide.

"What we do to the animals we do to ourselves" - making the link between wildlife and humans
Animal experiments have shown increased territorial marking in male mice exposed in the womb to certain endocrine disrupting chemicals such as the oestrogen-mimicking pesticide DDT. In humans it could be speculated that these sort of effects may translate into increased social aggression which may change the character of human communities.

People in the developing world are also at risk. Insecticides are widely used in tropical areas, and fat levels of DDT and its breakdown product DDE tend to be highest where it is used on crops and in homes for control of malaria. Wildlife and people living in the far north are also at risk, because many persistent substances are redistributed in a process termed global redistillation.

Pollutants may be preventing our children from reaching their full potential. Several studies in Europe and North America have linked reduced intelligence and behavioural effects with a child's exposure in the womb to PCBs (polychlorinated biphenyls) and co-contaminants. The WHO noted in 1998 that "subtle effects may already occur in the general population in developed countries at current background levels".

Toxic impacts on Inuit women and their offspring
The Inuit of northern Canada are a population of particular concern because they eat a lot of food from the sea, including predator mammals which tend to be heavily contaminated with toxic chemicals. Inuit women's breast milk is on average several times more contaminated with numerous organochlorine pesticides than that of women from southern Canada. Some research on the offspring of Inuit women has suggested an association between increased PCB exposure in the womb and increased ear and other infections, which may indicate that these substances can weaken the immune system.

Reducing our children's potential - a Mexican case study
Some of the most interesting recent field research carried out on POPs has occurred in Mexico. Striking differences have been exhibited in the development of children exposed to agricultural pesticides compared to children with minimal pesticide exposure.

In this work, researchers tested two groups of four and five year old children living in the Yaqui Valley region of northwestern Mexico. The two groups were similar in all respects, ranging from ethnicity to diet, except for their exposure to pesticides.

The families living in the foothills are ranchers who rely almost exclusively on traditional methods of pest control such as inter-cropping. The valley dwellers, on the other hand, live in an agricultural area that has seen heavy synthetic pesticide use since the 1940s. Samples of human breast milk and cord blood taken from valley women contained high levels of persistent contaminants including several targeted POPs: aldrin, endrin, dieldrin, heptachlor and DDE.

In tests developed to measure growth and development, the pesticide exposed valley children fell far behind their foothill-dwelling peers. The valley children exhibited:

  • decreased physical stamina in a jumping test,
  • a lack of eye hand co-ordination evident in their decreased ability to catch a ball,
  • diminished memory, and
  • a notable inability to draw a person, which is used as a non-verbal measure of cognitive ability.

The mix of pesticides used in the valley includes many synthetic POPs-listed compounds as well as non-persistent pesticides that jeopardise neurological development.

It cannot be stated with 100 per cent certainty that the pesticides are responsible for the effects in this specific case. However, the mounting scientific evidence that the dozen POPs are altering our children's ability to learn, to resist disease, and to reproduce has only added to the already compelling case for the rapid phase out of these notorious man-made compounds.
Download the report
An executive summary of Chemical Trespass: a toxic legacy is available to download in PDF format (60KB).

Research centre
For more information visit the toxics section of our online research centre.

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