The Discovery of lead in toys could be the tip of the iceberg
By Sarah S. Mosko, Ph.D.
Special to the OC Voice
It’s easy to blame China for the recent brouhaha over popular imported toys containing lead, a toxic heavy metal known to cause a myriad of developmental abnormalities including inattention/hyperactivity, learning deficiencies and delayed growth.
After all, the month of August 2007 alone saw a spate of five separate recalls by the Consumer Product Safety Commission (CPSC) for Chinese-made toys and another by Toys Я Us for imported vinyl baby bibs, all illegally containing lead in paints or inks (lead brightens the colors). Well-known toy importers Mattel, Fisher-Price and Schylling all made the recall lists.
Yet, a number of respected scientists are voicing strident concerns about toys and other products for children that contain other perfectly legal chemicals that might also be unsafe for young children. The discovery of lead in toys could be just the tip of an iceberg. What follows is an overview of what, beyond lead, has some scientists worried.
Phthalates (pronounced tha-lates)
Polyvinyl Chloride (PVC or vinyl) is one of the most common plastics used in children’s products. Since PVC is rock hard in its native state, plasticizers called phthalates are added to create softness and flexibility. Phthalates are not chemically bonded to the plastic polymer, just mixed in, so they’re free to migrate out during routine use.
Soft teething toys, bath books and rubber duckies, for example, traditionally contain phthalates, and the concern is that significant amounts can be ingested. Even toys not intended for oral use can be a source of ingestion since infants and toddlers put things in their mouths as a way to explore their world. Soft toys can be 10 to 40 percent, by weight, phthalate plasticizer.
Experiments in lab animals as early as 1999 by a team of US EPA researchers had shown that the male offspring of females exposed to common phthalates during pregnancy exhibit incomplete masculinization of their reproductive tracts—males were born with shrunken and malformed testes, sperm abnormalities and feminized nipples. Since phthalates are thought to act by blocking synthesis of the male sex hormone testosterone at a critical point in fetal development, they fall within a class of toxins called endocrine disruptors. Phthalates are also considered “hand-me-down” poisons because the exposed mothers are spared gross abnormalities.
In humans, sperm abnormalities have been found to be more frequent in men attending infertility clinics who have greater phthalate levels in their urine. Studies now also link phthalates to possible abnormal genitalia in American boys, premature breast development in Puerto Rican girls, and childhood asthma. Furthermore, the US EPA lists one common phthalate (DEHP) as a “probable human carcinogen” based on research documenting liver tumors in exposed animals.
Although much remains to be learned about which phthalates are of greatest potential harm to humans and at what level of exposure, the European Union moved in 1999 to reduce unnecessary risk to children by banning six phthalates from toys and other articles designed for infants and toddlers. Japan also instituted a more limited phthalate ban 5 yrs ago.
No phthalate has yet been banned by the U.S. government. In California, however, four phthalates are currently listed as reproductive toxins under the state’s Proposition 65 that requires products containing listed chemicals to sport a warning label.
The toy industry voluntarily reached an agreement with the CPSC in 1999 to eliminate PVC from objects designed specifically for mouthing. However, a 2003 investigation by Greenpeace revealed that PVC toys were still being sold by several manufacturers. And, a 2005 study commissioned by the U.S. Public Interest Research Group revealed that phthalates are still common in children’s teethers and bath toys, even those labeled “phthalate-free.”
Effective Dec 2006, the city of San Francisco instituted the first, in the nation, prohibition of the manufacture and sale of baby products containing any of six phthalates. As of this writing, a similar ban has passed the California state legislature (AB 1108) and is awaiting Governor Schwarzenegger’s signature. The states of New York, Oregon and Maryland are also considering phthalate bans.
Polycarbonate plastic baby bottles replaced glass ones decades ago. The building block of polycarbonate is the chemical bisphenol-A (BPA), an endocrine disruptor that mimics the action of the female sex hormone estrogen.
In fact, BPA was first investigated in the 1930s as a synthetic estrogen but eventually put to other uses when it was discovered that it could be polymerized to create polycarbonate, a clear and shatter-resistant plastic (e.g. 5-gallon water jugs). The epoxy resin that lines most food and beverage cans, including those holding infant formula, is also made from BPA. The chemical bonds that link the BPA subunits together break down in certain conditions and allow BPA to leach out. Allowing BPA in childcare products could thus expose children to the chemical.
Concern that early exposure to BPA might be dangerous was highlighted by an accidental discovery in 2003 by researchers at Washington State University: In female mice, incidental low-level exposure to BPA, via drinking from polycarbonate water bottles or being housed in polycarbonate cages, produced offspring with the wrong number of chromosomes. This condition is called aneuploidy and is a common cause of birth defects and miscarriage in humans. Subsequent research has shown that pre-natal exposure impacts the “grandchildren” too since the developing eggs of an exposed female fetus also show aneuploidy. Recent preliminary findings in women have in fact linked BPA exposure to miscarriage.
Well over 100 peer-reviewed studies have documented ill effects in laboratory animals stemming from low level BPA exposure, especially in pre-natal or in early post-natal life. In many cases, harmful effects were measured at dose levels below which the government lists as safe for humans. Included on the list are reduced sperm production, precancerous changes in the prostate and mammary glands, uterine damage, elimination of some normal sex differences in the brain, and insulin resistance (a precursor to diabetes).
Five popular brands of clear plastic baby bottles were found to leach BPA into their contents at levels found to be harmful in laboratory studies, according to a 2007 investigation by Environment California. Migration of BPA into the contents of resin-lined food and beverage cans, including infant formula, has been documented also.
The chemical industry continues to assure the public that BPA at current exposure levels does not represent a health hazard to fetuses and children, and the government has yet to take any action to the contrary.
Frederick vom Saal, a reproductive toxicologist at the University of Missouri-Columbia, has been particularly vocal in his criticism of both the industry, for its bias, and the federal government, for its failure to protect the public given the recent deluge of studies demonstrating harmful effects at doses encountered by young children. In 2006, vom Saal logged that 93 percent of the 149 studies that were government-funded found adverse health effects, whereas none of the 13 studies funded by the chemical industry reported any harm.
San Francisco stood alone in passing an ordinance in 2006 banning the manufacture and sale of BPA in baby products. However, it was never enforced and was subsequently repealed in April 2007, pending possible state-level action on the issue.
Flame retardants are added to many consumer products to prevent the spread of fire, so their introduction into bedding materials for infants makes perfect sense. However, the class of brominated flame retardants that is widely used, called PBDEs (polybrominated diphenyl ethers), is associated with notable health effects, especially in young animals. Infant exposure from PBDE-treated bedding fabrics or foam could occur by several routes—direct skin contact or by inhalation or ingestion of chemical-laden dust. Furthermore, PBDEs diffuse into air since they are not chemically bonded to targeted products.
The possible risks of early PBDE exposure have not been worked out fully but include derailment of brain development and disruption of both sex and thyroid hormones. For example, a series of experiments from the laboratory of Per Eriksson at Uppsala University in Sweden demonstrated permanent impairments of learning and memory in animals given a single dose soon after birth.
PBDEs are sold in three commercial mixtures (penta, octa and deca), so-named by the number of bromine atoms most represented in the component compounds. Until recently, octa and especially penta were thought to be more toxic than deca which dominates the global market currently. However, new data from U.C. Berkeley researchers indicates that deca can be broken down by bacteria as well as sunlight into more toxic forms, so it might be equally toxic in the long run.
The European Union passed bans on penta and octa in 2004. California also passed a blanket ban by 2008 on these two forms in all consumer products, not just those intended for children. Several other states have followed suit. Legislation is pending in California and a handful of other states to also limit the use of deca.
The US EPA has not formally banned any PBDE, but rather reached an agreement with U.S. manufacturers to voluntarily cease production of penta and octa as of 2004. However, a major loophole allowing continued importation of products with these chemicals still stands. A 2006 report from the U.S. Public Interest Group, that found infant bedding materials on the shelves testing positive for multiple PBDEs, is a case in point.
Virtually every investigation in recent years has shown phthalates, BPA and brominated flame retardants to be accumulating in human tissues, including those of infants and young children.
Even though much remains to be learned about the extent to which developing bodies are affected by these compounds, we already know that the young are most vulnerable to the disruptive effects of toxins in general. Certainly China deserves a good dose of the blame for the ongoing flap about toxic lead, yet we have to look homeward to explain how it is that chemicals now known to create havoc in developing animals are still allowed in childcare products.
Some 80,000 chemicals have been introduced into commerce since World War II, most without any human health safety testing, and those used to manufacture items for children are no exception. The national authorities responsible for insuring product safety are the US EPA, the CPSC and the FDA. All three lack application of a “precautionary principle” wherein a chemical or product is allowed to be marketed only after it is proven safe. Already formally adopted by the European Union, this approach errs on the side of safety and places the burden of proof on the manufacturers and importers that profit from the sale of their products.
The virtual opposite approach prevails here in the U.S. Nearly all the health safety testing performed on phthalates, BPA and PBDEs, for example, was undertaken quite recently and well after these chemicals enjoyed widespread use in childcare products for decades. Equally troublesome is the fact that it’s near impossible to find out what chemicals a given item might contain, since labeling is not required.
It’s a welcome change that the discovery of lead toys imported from China has nudged America’s parents to start thinking more deeply about the real costs of cheap toys. However, by not holding industry responsible for the health safety of their products we, as a society, are effectively placing corporate profits ahead of the health of our children. Put another way, does a “free market” include the freedom to pollute the bodies of children?
It seems a sad day indeed that, without a serious overhaul of how chemicals are regulated in this country, parents may well find themselves looking wistfully back to the good ole days when possible “choking hazard” was the only safety risk they had to consider when shopping for their youngsters.