Researchers in the United States have found phthalates, a hormone-disrupting chemical used in many plastics and personal care products, in every one of a group of 163 babies they tested.
More than 80 per cent of the infants had at least seven different types of phthalates, a finding attributed to the widespread use of baby shampoos, skin lotions, and baby powders that contain the chemical. The researchers, who are publishing their results today in the journal Pediatrics, theorized that the children are absorbing the chemicals through their skin when parents use personal care products on them.
It is not known what health risks, if any, these exposures pose, but previous research has found the chemicals are capable of altering reproductive hormone levels in young children exposed through their mother's milk. One of the researchers who conducted the new study recommended that parents, as a precaution, try to reduce exposures by cutting down on the use of lotions and shampoos on babies.
"We really just don't want chemicals in our bodies that are changing our hormone concentrations," said Dr. Sheela Sathyanarayana, a pediatrician at the University of Washington in Seattle. "It's prudent to just try and decrease your exposures as much as possible at that early age, especially when these products aren't necessary."
Personal care products for babies typically don't list phthalates as an ingredient in the United States or Canada, but the chemical may be in them anyway.
A check of the database of the 65,000 cosmetics sold in Canada "found no cosmetics marketed for infants and children that include phthalate as an ingredient," according to an e-mailed statement to The Globe and Mail by Health Canada.
However, manufacturers are adding phthalates without disclosing their presence because they are included in listed items.
"While phthalates are not deliberately added to cosmetic products intended for babies and children, traces of phthalates may be found in the fragrance ingredients of these products," Health Canada said.
Because there is concern over the chemical, Health Canada has begun a two-year study on phthalate levels in personal care products, including some marketed for babies, and their potential to cause inhalation exposures.
The researchers didn't find an association between the chemical and the use of diaper wipes or diaper rash creams.
Phthalates (pronounced THA-lates), are a family of chemicals that, besides their use in fragrances, are also added as a softener to many types of plastic. They are one of the substances that give vehicles their distinctive new-car smell.
Many researchers are worried about them because they interfere with male reproductive hormones and laboratory animal experiments have linked early life exposures to male genital tract abnormalities.
Some scientists have theorized that low-dose exposures to the chemicals may be a factor in such medical problems as undescended testicles and hypospadias, a congenital disorder where a boy's urinary opening is located on the underside, rather than on the tip, of the penis.
These concerns have led to increased regulatory action against the chemicals, the most dramatic a decision by the European Parliament in 2005 to ban six types of phthalates from children's toys. Health Canada is also currently considering a ban on one type of phthalate in toys used by children under the age of 3.
In the new research, scientists checked urine squeezed out of used diapers for the presence of metabolized forms of the chemicals, indicating that the phthalates had passed through living tissues and weren't from the diapers themselves.
The tests were conducted on infants born from 2000 to 2005, who lived in California, Minnesota or Missouri. Parents were asked to indicate what personal care products they used on their children in the day before the sample was collected, allowing researchers to link exposures to shampoos and lotions.
There was a huge difference in individual readings, with some babies having extremely low levels and others quite high. For one type of phthalate, one of the babies had 4,481 parts per billion in urine, while half of those tested had less than 60.9 ppb.
Dr. Sathyanarayana said wide ranges are a sign that the amounts of the chemicals in a person's individual environment vary greatly, depending on the type of consumer products they use. The research was funded in part by the U.S. Environmental Protection Agency.