Health Studies

health-studies_1_0

“Super Lice” Resistant to Over the Counter Chemical Treatments

louses2In many schools, kids aren’t the only ones going back to school. It is estimated that roughly 10 million children worldwide between the ages of 3 and 11 are infected with lice annually. And recent studies report that many commercial products sold to treat lice are no longer working. The lice have built up a resistance to the chemicals.

So, what do we do? Even if the chemicals did work, there is concern over their toxicity to humans and the environment. In order to treat lice effectively, combing is a bare necessity, but Stanford’s Packard Children’s Health Services Pediatric Hotline says adding rosemary extract to our shampoo can help repel and kill lice.

Fortunately, Original Sprout’s 2-n-1 Hair & Body Wash, Natural Shampoo, and Miracle Detangler all contain Organic Rosemary and Organic Calendula. So, we use our great, moisturizing, natural shampoos on the whole family, then spritz on a little of our leave-in detangler and lice are sure to think twice about jumping into any of our lovely locks. Worry-Free Preventative Luxury in two simple steps!

Hairdressers more prone to breast cancer

hairstylistHairdresser styling red-haired womanHeadteaching, pharmacy and hairdressing are three jobs carrying an increased risk of breast cancer, according to a Swedish study The survey, of more than a million women revealed these inexplicable patterns, also implicating systems analysts, beauticians and telephone operators as having a higher than normal risk.

Writing in the American Journal of Public Health, Dr Marina Pollan and Dr Per Gustavsson said that some of the statistical blips might be due to the career paths followed by white collar workers. The study’s authors speculated that exposure to chemicals used in the hair and beauty industry might contribute to the extra risk. Currently, one in 12 British women and one in eight US women will get the disease at some point in their lives.

What Are PARABENS?

Preservative chemicals found in samples of breast tumours probably came from underarm deodorants, UK scientists have claimed. Their analysis of 20 breast tumours found high concentrations of para-hydroxybenzoic acids (parabens) in 18 samples. Parabens can mimic the hormone estrogen, which is known to play a role in the development of breast cancers. The preservatives are used in many cosmetics and some foods to increase their shelf-life. “From this research it is not possible to say whether parabens actually caused these tumours, but they may certainly be associated with the overall rise in breast cancer cases,” says Philip Harvey, an editor of the Journal of Applied Toxicology, which published the research. “Given that breast cancer is the largest killer of women and a very high percentage of young women use underarm deodorants, I think we should be carrying out properly funded, further investigations into parabens and where they are found in the body,” Harvey told New Scientist.

Could lavender and tea tree oil act as endocrine disruptors?

ABC SCIENCE ONLINE

The lavender and tea tree oils found in some soaps, shampoos, hair gels and body lotions can produce enlarged breasts in boys, researchers report. These plant oils were linked to abnormal breast development in three boys, which was reversed when they stopped using them, write Dr Clifford Bloch of Pediatric Endocrine Associates in Colorado, and colleagues. They say their study, published today in the New England Journal of Medicine, suggests these oils can act in ways similar to the hormone estrogen. “This report raises an issue of concern, since lavender oil and tea tree oil are sold over the counter in their ‘pure’ form and are present in an increasing number of commercial products, including shampoos, hair gels, soaps, and body lotions,” the researchers write. “Whether the oils elicit similar endocrine-disrupting effects in prepubertal girls, adolescent girls, or women is unknown.”

While it is very common for boys to develop temporary breast enlargement as they go through puberty, the condition is very rare in young boys. Doctors call the condition prepubertal gynaecomastia, and often find no explanation for it. The researchers found the condition in three otherwise healthy boys, aged 4, 7 and 10. “I got wind of it because I was given a clue by a patient,” Bloch says. That case involved the 4-year-old “who was using absolutely nothing on his skin except a lavender oil preparation that his mother had obtained from a homeopath. She used to rub it on his chest and body every night” because lavender, in complementary medicine circles, is said to have healing properties. Several months after the boy stopped getting the ‘healing balm’, his breasts returned to normal. Meanwhile, Bloch then began to see lavender crop up in other cases, including the 10-year-old, who was using a hair styling gel and shampoo that contained both lavender oil and tea tree oil. There was also a 7-year-old, who had been using lavender-scented soap and skin lotions. In laboratory tests, scientists at the US National Institute of Environmental Health Sciences (NIEHS) found that both substances can mimic the action of the female hormone estrogen. They can also block male hormones that control both masculine characteristics and inhibit the growth of breast tissue.
— ABC Science Online

FOR IMMEDIATE RELEASE
February 08, 2007

CONTACT: Kevin Donegan or Marisa Walker, Breast Cancer Fund, (415) 346-8223; Stacy Malkan, Campaign for Safe Cosmetics, (202) 321-6963; David Steinman, author, “Safe Trip to Eden,” (310) 403-6995; Sheila Huettl, Freedom Press, (323) 208-2629

Chemical Found in Soy Products Could Damage Sperm and Impair Fertility

The plant chemical GENISTEIN, which is found in soy products and legumes, could damage sperm and lead to fertility problems, according to a study presented on Wednesday at the… European Society of Human Reproduction & Embryology’s annual conference in Copenhagen, Denmark, Reuters reports. Lynn Fraser, a professor of reproductive biology at King’s College London, tested the chemical — which can mimic the effect of the female hormone estrogen — on human and mouse sperm (Reaney, Reuters, 6/21). Fraser found that human sperm were more than three times as likely to lose their acrosomes — caps that enable them to penetrate an egg at fertilization — an hour after genistein exposure than they were before exposure (Fleming, Daily Telegraph, 6/22). Although genistein affects sperm’s ability to penetrate an egg, a woman’s intake of genistein-containing foods likely has a greater effect on fertility than a man’s consumption, according to the researchers (Reuters, 6/21). Fraser said that women trying to become pregnant might be able to increase their chance of pregnancy by avoiding foods with high concentrations of genistein during ovulation (Roberts, BBC News, 6/21).
Tea tree oil faces ban over health fear

Scientists say even small amounts could provoke rashes and allergies

Tea tree oil, the increasingly popular remedy for everything from spots to insect bites and vapour rubs, is under threat of being banned by the European Union. The EU has said that even small amounts of the undiluted oil could be unsafe and unstable after clinical trials found users risked rashes and allergies. Cosmetic products, such as shampoo and bath oils, that use the oil in concentrations of less than 1 per cent are safe. But the toiletries and cosmetics firms that produce the neat form of the natural remedy have been given until June to convince a panel of scientists that the oil is safe to sell to the public. The warnings follow revelations that boys have been warned against using oils or hair gels that contain tea tree oil after three cases of them growing breasts were reported.

Researchers in the US believe that the oils may have hormone-like properties that lead to gynaecomastia – the growth of breasts. When the boys stopped using the oils, the breasts disappeared. Writing in New England Journal of Medicine, the researchers say that the repeated use of such oils may disrupt hormonal function. It has also been revealed that tea tree oil in cosmetics and creams could increase the chances of catching ‘superbug’ infections in hospital. Exposure to low doses of the oil made pathogens such as MRSA, E.coli and salmonella more resistant to antibiotics.

‘Because essential oils are natural products, the public often assumes they must be safe,’ says Frances Fewell, director of the Institute for Complementary Medicine. ‘You should never apply any sort of essential oil directly to the skin without diluting it first in a suitable carrier oil. Tea tree oil has become very popular, and many people have started applying it directly to deal with acne and skin infections. In fact this is a very aggressive oil. The skin can dry out, blister or form a rash.’

In a strongly worded report, the EU’s Scientific Committee on Consumer Products has said it has serious concerns about the neat oil which, it found, is ‘a severe irritant’ to the skin and ‘degraded rapidly’ if exposed to air, light and heat. The SCCP said existing safety tests were inadequate and that even widely sold toiletries were of ‘questionable stability and were being sold without adequate proof of safety’. ‘The sparse data available suggest undiluted oil as a commercial product is not safe,’ the committee’s report said. ‘Our major concern is that toxic and risky chemicals become even more potent – up to three times as strong – if stored at room temperature, and exposed to light and air.’

‘Whether or not the SCCP will be reassured by whatever the toiletries and cosmetics firms give them in June, I’m not sure,’ said Christopher Flower, head of the British Cosmetic, Toiletry and Perfumery Association. ‘They may have a view on whether it is still appropriate for the public to use it neat at all. They may well decide that, regardless of the industry’s presentations to them, the neat oil should not be used. Or they may simply say it should not be used frequently or over all of the body.’

Essential oils are concentrated oils extracted by passing steam through plants. The steam vaporises the volatile aromatic chemicals in the plant and these are then distilled. Not all essential oils, however, have gone through this process. ‘Essential oils are widely available under various forms of labelling and packaging, sometimes with insufficient regard for safety,’ says Sylvia Baker of the Aromatherapy Trade Council. ‘Many are of poor quality, and some are totally synthetic. There are companies that specialise in making nature-identical oils and then offering them as pure products. Others are bulked with cheaper oils and synthetics.’

The oil, which is derived from the Australian melaleuca tree and has been a traditional remedy among Australian Aboriginals for centuries, is famous for its antiseptic properties. Used by Australian troops for battlefield injuries in the First World War, it is now found in shower gels, toothpastes, mouthwash and face cleansers, to cure skin complaints, to treat cuts and burns, and as an insect and lice repellent.

Soy Cancer Warnings

CANCER patients are being warned to avoid soy because it can accelerate the growth of tumours.

The Cancer Council NSW will issue guidelines today, warning about the dangers of high-soy diets and soy supplements for cancer patients and those people in remission from cancer. At particular risk are people suffering from hormone-dependent cancers, including breast and prostate cancer – the two most common types of cancer in Australia. Cancer survivors are also being urged to avoid high doses of soy, as they may be more vulnerable to a relapse. Research has found high consumption of soy products can also limit the effectiveness of conventional medicines used to treat the disease.

“There is evidence to suggest that women with existing breast cancer or past breast cancer should be cautious in consuming large quantities of soy foods or phyto-oestrogen supplements,” a position statement from the Cancer Council says. “Women with current or past breast cancer should be aware of the risks of potential tumour growth when taking soy products. “The Cancer Council does not support the use of health claims on food labels that suggest soy foods or phyto-oestrogens protect against the development of cancer.”

Health experts are particularly concerned that breast-cancer sufferers who take soy or phyto-oestrogen supplements could feed the disease and reduce the effectiveness of their treatment. Soy, which is present in soy beans, soy milk, tofu, tempeh and some breads, contains phyto-oestrogens that mimic the actions of hormones in the body. This means it may interfere with cancer drugs such as Tamoxifen, which works by suppressing the female hormone oestrogen. Men with prostate cancer are also being warned against high soy consumption, as phyto-oestrogens may imitate the male hormone androgen. Although the Cancer Council has warned against soy supplements, it believes an occasional intake of soy food is still safe for cancer patients.

Cancer Council nutritionist Kathy Chapman said soy supplements could contain dangerously high doses of phyto-oestrogens. “If you were a woman with breast cancer and thought, ‘I’m going to radically change my diet and have very large portions of soy at every meal’, it could be a problem,” Ms Chapman said. “For someone who has tofu once or twice a week and drinks a bit of soya milk, it’s not so much of a problem.”

Soy has earned a reputation as a natural “superfood” that cuts the risk of breast or prostate cancer, and is commonly included in women’s health supplements. This claim was based on findings that cancer rates were lower in Asia, where soy consumption is high. But soy would lower the risk of contracting cancer “only a little”, according to the Cancer Council. “While they may have a protective effect, there is also some evidence that phyto-oestrogens may stimulate the growth of existing hormone-dependent cancers,” the council’s statement said.

The risk of contracting other non-hormone-dependent cancers, including bowel cancer, would be unaffected by soy intake. The Cancer Council was prompted to investigate the issue after being inundated with questions about the role of soy in cancer patients’ diets. “We felt we were getting a lot of calls on our hotline about this topic,” Ms Chapman said.

Breast-cancer survivor Susie Musarra was surprised by the new evidence about soy. The Sydney mother of two was diagnosed five years ago. She followed a healthy diet, containing plenty of fruit and vegetable juices, during chemotherapy treatment. “It’s really confusing, because you get a lot of conflicting information about what to eat,” she said. “It’s good to have this advice, because it helps you make an informed decision – and the Cancer Council is a reputable source.”

The effect of phytoestrogens on breast cancer

Phytoestrogens are a group of chemicals found in plants that can act like the hormone estrogen. Estrogen is a hormone necessary for childbearing and is involved with bone and heart health in women. Higher exposure to estrogens over a lifetime is linked with increased breast cancer risk.

Working as estrogen mimics, phytoestrogens may either have the same effects as estrogen or block estrogen’s effects. Which effect the phytoestrogen produces can depend on the dose of the phytoestrogen. The phytoestrogen can act like estrogen at low doses but block estrogen at high doses. Estrogen activates a family of proteins called estrogen receptors. Recent studies have shown that phytoestrogens interact more with some members of the estrogen receptor family, but more information is needed about how these receptors work, especially in breast cancer. Finally, phytoestrogens acting as estrogen mimics may affect the production and/or the breakdown of estrogen by the body, as well as the levels of estrogen carried in the bloodstream.

Phytoestrogens – acting differently from estrogen – may affect communication pathways between cells, prevent the formation of blood vessels to tumors or alter processes involved in the processing of DNA for cell multiplication. Which of these effects occur is unknown. It is very possible that more than one of them may be working. Also, the effects in various parts of the body may be different. from Phytoestrogens and Breast Cancer.

Oils Linked to Breast Growth in Boys

BOSTON — Lavender and tea tree oils found in some shampoos, soaps and lotions can temporarily leave boys with enlarged breasts in rare cases, apparently by disrupting their hormonal balance, a preliminary study suggests.

essential-oilsWhile advising parents to consider the possible risk, several hormone experts emphasized that the problem appears to happen infrequently and clears up when the oils are no longer used. None of those interviewed called for a ban on sales.

The study reported on the condition, gynecomastia, in three boys ages 4, 7 and 10. They all went back to normal when they stopped using skin lotions, hair gel, shampoo or soap with the natural oils.

It’s unclear how often this problem might crop up in other young children.

These plant oils, sometimes called “essential oils,” are added to many health-care products, usually for their scent. The oils are sometimes found in other household products or sold in purer forms. Tea tree oil is sometimes used in shampoos for head lice.

The suspected effect in this study is blamed on some chemical within the oils that the body processes like estrogen, the female hormone that promotes breast growth.

The findings were being reported Thursday in the New England Journal of Medicine. The federally funded study came out of the University of Colorado and the environmental health branch of the National Institutes of Health. The findings were first released last year at a science meeting.

The three boys were brought to their doctors with overdeveloped breasts that looked like those of girls in early puberty. They were sore in one case. For each boy, doctors could tie the problem only to their use over several months of the natural-oil products.

The researchers suspected that the oils might be upsetting the boys’ hormonal balance. So they did a series of laboratory tests to check how these oils work within human cells. The oils appeared to mimic estrogen and block the male hormone androgen.

On product labels, the oils sometimes are listed by their scientific names: Lavandula angustifolia (lavender oil) and Melaleuca alternifolia (tea tree oil). Such products do not require government approval to be sold unless they make specific health claims.

Marijuana and soy products also have been linked to gynecomastia.

Dr. Clifford Bloch, a hormone specialist in Greenwood Village, Colo., who treated the three boys, recommended that parents “be cautious” with such products, especially for prolonged use. “I would not give these products to my children,” he said in an interview.

Bloch said he also suspects the oil played a role in a handful of young girls he saw for a similar condition, including a 17-month-old whose parents were washing her bottles with a lavender-scented soap.

Others sounded less worried. “It takes very little estrogen to cause gynecomastia in a young child,” said Dr. Richard Auchus, a University of Texas Southwestern Medical Center hormone expert who knew of the study findings. “If they’re getting it for a brief period of time, that really shouldn’t cause long-term problems.”

Also, the research did not pinpoint any specific estrogen-like compounds in the oils or look for them in a range of products. Chemist Steven Dentali, at the industry group American Herbal Products Association, said that warning people to avoid such oils “is premature without the additional basic research needed to bolster the case that the issue here is both real and significant.”

Gynecomastia is very common in boys during the hormonal changes of puberty. But it also occurs as a rare condition in younger boys, men, and girls before puberty.

Bloch, the study doctor, said it’s unknown if such oils could hurt women with estrogen-fed breast tumors.

CANCER-CAUSING CHEMICAL FOUND IN CHILDREN’S BATH PRODUCTS

Women’s Shampoos and Body Wash also Contaminated

WASHINGTON — A hidden cancer-causing petrochemical has been found in dozens of children’s bath products and adults’ personal care products, in some cases at levels that are more than twice the U.S. Food and Drug Administration’s lenient recommended maximum. Laboratory tests released today revealed the presence of 1,4-Dioxane in products such as Hello Kitty Bubble Bath, Huggies Baby Wash, Johnson’s Baby Wash, Scooby-Doo Bubble Bath and Sesame Street Bubble Bath. The tests also found the carcinogen in Clairol Herbal Essences shampoo, Olay Complete Body Wash and many other personal care products. 1,4-Dioxane is a petroleum-derived contaminant considered a probable human carcinogen by the U.S. Environmental Protection Agency and a clear-cut animal carcinogen by the National Toxicology Program. It is also on California’s Proposition 65 list of chemicals known or suspected by the state to cause cancer or birth defects. Because it is a contaminant produced during manufacturing, the FDA does not require it to be listed as an ingredient on product labels.

“Regrettably, 1,4-Dioxane contamination is just the tip of the iceberg,” said Jeanne Rizzo, R.N., executive director of the Breast Cancer Fund, a founding member of the Campaign for Safe Cosmetics. “Because the FDA does not require cosmetics products to be approved as safe before they are sold, companies can put unlimited amounts of toxic chemicals in cosmetics.” Steinman said parents should be outraged that companies are willing to spend a significant amount of money on entertainment licensing agreements that entice children but won’t spend pennies to remove contaminants such as 1,4-Dioxane. “Consumers who have young children, as I do, have the right to expect the highest purity in children’s products,” Steinman said. “I call on American consumers to say no to dangerous petrochemicals in their children’s cosmetic and personal care products.”

Product

Baby & Children’s Consumer Products

  • 1,4-Dioxane concentration
  • Disney Clean as Can Bee Hair & Body Wash (Water Jel Technologies) 8.8 ppm
  • Disney Pixar Cars Piston Cup Bubble Bath (MZB Personal Care) 2.2 ppm
  • Gerber Grins & Giggles Gentle & Mild Aloe Vera Baby Shampoo 8.4 ppm
  • Hello Kitty Bubble Bath (Kid Care) 12 ppm*
  • Huggies Baby Wash Shea Butter 4.0 ppm
  • Huggies Natural Care Baby Wash Extra Gentle and Tear Free 4.2 ppm
  • Johnson’s Head-to-Toe Baby Wash (Johnson & Johnson) 5.3 ppm to 6.1 ppm
  • Johnson’s Kids Tigger Bath Bubbles (Johnson & Johnson) 5.6 ppm to 7.9 ppm
  • Johnson’s Kids Shampoo Watermelon Explosion (Johnson & Johnson) 10 ppm*
  • Lil’ Bratz Mild Bubble Bath (Kid Care) 3.7 ppm
  • L’Oreal Kids Orange Mango Smoothie Shampoo 2.0 ppm
  • Mr. Bubble Bubble Bath Gentle Formula with Aloe 1.5 ppm
  • Rite-Aid Tearless Baby Shampoo 4.3 ppm
  • Scooby-Doo Mild Bubble Bath (Kid Care) 3.0 ppm
  • Sesame Street Wet Wild Watermelon Bubble Bath (The Village Company) 7.4 ppm

Adult Consumer Products

  • Clairol Herbal Essences Rainforest Flowers Shampoo 23 ppm*
  • Olay Complete Body Wash with Vitamins (normal skin) 23 ppm*
  • Suave Naturals Passion Flower 2.0 ppm

*Product was at or above FDA maximum

Reduce fetal exposure to BPA and phthalates, experts say

With Health Canada recently banning plastic baby bottles made from bisphenol A and proposing to ban certain toys, questions arise about whether similar actions should be taken to safeguard pregnant women

Citing possible risks to young children, Health Canada recently banned plastic baby bottles made from bisphenol A and is proposing to ban toys containing six types of phthalates, best known as the rubber duck chemical.

Singling out babies and toddlers for special protection against harmful chemicals is a good idea because infants, with their rapidly growing bodies and unique exposure patterns, can be more vulnerable to dangerous chemicals than are most adults.

But a question has arisen about Health Canada’s actions: If young children shouldn’t come into contact with the two chemicals, what about pregnant women and their fetuses, which are even more susceptible to harmful compounds, especially those with hormonal impacts, like these man-made substances?

Bisphenol A is an estrogen mimic, meaning exposure gives an extra hit of the female hormone, while phthalates interfere with testosterone production, reducing levels of the crucial male hormone.

During fetal development, in particular, humans are extremely sensitive to sex hormones. Everything from genital development to brain organization is choreographed by specific levels of these hormones circulating in the womb at precise points in the pregnancy. If levels are skewed by synthetic chemicals, there is the risk of irreversible, life-long changes occurring.

“Pregnant women and the fetus are in fact the greatest target group for all of these chemicals,” says Frederick vom Saal, a professor at the University of Missouri and one of the leading researchers in the U.S. investigating bisphenol A, or BPA as it is also known.

Health Canada needs “to now take the next logical step” and consider wider restrictions on the chemicals to reduce exposures in pregnant women, contends Dr. vom Saal. The agency shouldn’t assume “that by just targeting protections for newborns they’ve done enough.”

Although Health Canada took action against the two chemicals to protect children, the most provocative research on both compounds has been done on pregnant rodents and on their pups during early neonatal life, the period that corresponds to the last part of gestation in humans. Because conducting experiments on pregnant women would be unethical, these animal laboratory tests are designed to flag possible harmful effects on people.

Such experiments have found dramatic results, including enlarged prostates, skewed mammary ducts that in women would translate into increased breast cancer risk, and the feminization of male genitals.

Safeguards for pregnant women are needed, agreesanother top researcher in the field, Shanna Swan, director of the Center for Reproductive Epidemiology at the University of Rochester’s school of medicine, and an authority on phthalates. While children are sensitive to the chemicals, they’re “not as sensitive as the fetus. There is no question about that,” says Dr. Swan.

Dr. Swan has published a study finding that women who have higher levels of phthalates during pregnancy give birth to boys with a slightly shorter distance from the start of their genitals to the anus, mirroring a discovery made in male rodents exposed to the chemical. In rodents, the shrinkage is viewed as feminizing the male genital tract, but the effect occurred at far higher doses than what is found in people exposed to the chemicals.

Nonetheless, because there is animal evidence of harm during gestation, Dr. Swan says “we should assume until proven otherwise that it’s reproductively toxic to humans.”

Health Canada said it is monitoring research on the chemicals, but it believes the weight of evidence does not yet warrant measures to reduce exposures by pregnant women.

“Health Canada will take appropriate action if a risk to human health is identified,” it said in an e-mailed response to questions.

But the federal agency has begun several studies on pregnant women and their babies to see whether the animal research is onto something, and has ordered up research to see if the genitals of newborns have been affected by their mothers’ exposure to the two chemicals.

Last month , for instance, it posted a notice indicating that it has asked a McMaster University researcher to study pregnant women to find out whether BPA affects the anogenital distance in their babies. It has a similar study on phthalates to try to duplicate Dr. Swan’s findings.

In human babies, as in rodent pups, males typically have a larger distance from the anus to the genitals than females, and it is likely that anything reducing the sex difference would be hormonal in nature.

The chemical industry said it welcomes the research and predicted its products will get a clean bill of health. “We are confident that the levels of bisphenol A that will be found will be extremely low and we think it’s unlikely that any health effects will be observed,” said Steven Hentges, spokesman for the American Chemistry Council.

The council also represents phthalate makers and has argued that the research showing effects on the genitals of boys is flawed.

It’s been relatively easy for Health Canada to introduce measures restricting infant exposure to phthalates and BPA by ordering them out of just a few products such as plastic baby bottles and toys. If it decides pregnant women need protection, it faces a much harder task because products containing the substances are ubiquitous.

“The ability of governments to actually tackle adult exposures is going to be extremely challenging,” Dr. vom Saal predicted.

Pregnant women wanting to reduce their exposure while the government researches the issue may have difficulty because many plastic products don’t disclose what they’re made from, although some polycarbonates containing BPA carry the plastic industry’s symbol of a triangle encasing the number seven, while polyvinyl chloride, which often contain phthalates, sometimes carries a triangle encasing the number three.

As well, there isn’t a full understanding of how humans are being exposed to the chemicals, but residues in food from packaging and processing equipment are suspected. Some researchers believe other sources might be important, such as breathing dust containing the chemicals or absorbing them through the skin, as people would do for compounds in cosmetics.

The uterus doesn’t offer protection against the compounds, which have been detected in the placenta, amniotic fluid and umbilical cord blood, indicating that maternal exposure leads to fetal exposure.

The amounts of exposure in people are low, but according to some experts, they are still worrisome. Blood concentrations of bisphenol A are typically a couple of parts per billion, while phthalates measured in urine can be thousands of parts per billion. One part per billion is a tiny amount, the equivalent of one second of elapsed time over nearly 32 years.

But Dr. vom Saal cautioned that these concentrations are far higher than the natural amounts of estrogen in people, which are in the parts per trillion, and testosterone, in the parts per billion. He says that because people’s hormone systems are already operating at their natural levels, any alterations caused by phthalates and BPA should be a source of concern.

Health Canada studying effect of chemicals on infant genitals

Health Canada has quietly been studying a delicate topic: Whether or not the genitals of Canadian babies are being altered by their moms’ exposure to bisphenol A or phthalates during pregnancy.

The research will measure the distance between the start of a baby’s genitals and its anus, a space that on average is larger in boys than in girls. If the space is getting smaller, it means boys are being born less manly, and likely to have smaller penises and testicles.

The phthalate study is under way and will take up to five years to complete, while the bisphenol A research is just starting.

Phthalates, which are able to reduce levels of the male hormone, testosterone, are found in everything from polyvinyl chloride shower curtains to floor tiles, where they’re used to make plastics less brittle. They’re also added to cosmetics and perfumes to make the fragrance last longer.

Bisphenol A, an estrogen mimic, is the main ingredient in polycarbonate plastic products, including office water-cooler jugs, lenses for eyeglasses and the protective coatings on compact discs. It’s also in the epoxy liners found on the inside of most food and beverage cans, and in some carbonless paper register receipts.

All BPA is made by humans and isn’t found in nature, although there are some microbial sources of phthalates.

Scientists have known for years that dosing pregnant rodents with phthalates feminizes their male offspring, giving them female-like areolas and nipples, and smaller genital tracts. The amounts used to prompt the effects are far above what people are exposed to, but recently, researchers in the U.S. believe that they have detected slightly smaller genitals in boys born to mothers with higher-than-average phthalate exposure during pregnancy.

Bisphenol A has raised health concerns too, with tests in experimental animals leading to such conditions as early puberty, genital malformations and increased prostate growth, often at low doses given during fetal development.

The federal government is also testing several thousand Canadians for their BPA and phthalate levels, but the results are not yet available. Bio-monitoring in the U.S. has found that nearly everyone carries detectible amounts of the two chemicals. One survey conducted between 2003 and 2004 found about 93 per cent of Americans have bisphenol A in their bodies, and researchers looking for phthalates have found a similar percentage.

This resource was written by Martin Mittelstaedt Environment Reporter
Published on Thursday, Aug. 06, 2009 7:11PM EDT
Last updated on Friday, Aug. 28, 2009 3:41AM EDT