Children are vulnerable

Jul. 15, 2010.  Children are not little adults. Their small, developing bodies receive greater exposures by weight than adults to contaminants in air, water, food, and everyday products. In addition, their immature metabolism and organ systems are typically less capable of fending off chemical assaults. And subtle damage to developing bodies that does not trigger immediate health effects may lead to disease later in life.

In its recently updated cancer risk guidelines, the Environmental Protection Agency (EPA) explicitly acknowledges the importance of childhood exposures. The Agency concluded, after a review of 23 studies of early life exposures to cancer-causing chemicals, that carcinogens are typically 10 times more potent for babies than for adults, and that some chemicals are up to 65 times more powerful (EPA 2005). Despite these and other well-documented concerns regarding children's sensitivity to harmful substances, no special protections exist regarding ingredients in personal care products marketed for babies and children.

Reasons for children's increased vulnerability to chemicals

According to the National Academy of Sciences, several factors contribute to children's exceptional vulnerability to the harmful effects of chemicals (NAS 1993):

  • A child's chemical exposures are greater pound-for-pound than those of an adult.
  • Children are less able than adults to detoxify and excrete chemicals.
  • Children's developing organ systems are more vulnerable to damage from chemical exposures.
  • Children have more years of future life in which to develop disease triggered by early exposure.

Consider the skin. Studies confirm what any parent knows: an infant's skin is soft and delicate (Fluhr 2000; Giusti 2001). Infant skin is also considerably thinner than adult skin; in fact, the thickness of children's skin increases linearly with age, typically reaching a maximum at age 20 (Tan 1982). The thin skin of a newborn may well be more permeable to specific chemicals than the skin of an adult. Compounding this fact, the surface area of a child's skin relative to body weight is greater than adults, such that the potential dose of a chemical following dermal exposure is likely to be about 3 times greater in infants than in adults (West 1981; Clewell 2002).

Babies and children thus receive far greater exposures than adults to ingredients in personal care products slathered on their skin. Sensitivity to many chemicals in children's care products causes eczema (Katelaris 2006), and may produce more subtle damage later in life. Exposures to industrial chemicals may prime children for adult diseases (NAS 1993; EPA 2005), just as a few severe sunburns during childhood doubles the likelihood of developing malignant melanoma later in life (Oliveria 2006).

A recent review by government scientists of the "critical windows" of vulnerability reveals an urgent need for public health policies that recognize childhood sensitivity (Selevan 2000). Scientists have developed a much fuller understanding of children's vulnerability to chemicals, discovering links between a host of health problems - including asthma, childhood cancer, and brain damage - and such common contaminants as solvents, pesticides, PCBs, and lead (Trasande 2004). A recent National Academy of Sciences study suggests that environmental factors contribute to at least 28% of childhood developmental disabilities (NAS 2000). As a whole, these windows facilitate more pronounced risks and effects for chemical exposures in childhood than adulthood.

But health and environmental officials have been slow to act on the wealth of studies on childhood vulnerability produced in the past 20 years. EPA required nearly a decade of review to update its cancer risk guidelines in 2003, finally conceding the importance of childhood exposures (EPA 2005). The new policy targets only cancer, leaving EPA with no formal policy regarding childrens' vulnerability to chemicals that damage the immune system, the brain, the hormone system, or a host of other potential targets, despite evidence that children face higher risks for harm.

Health trends of concern

Analysis of our survey data revealed that children are exposed to many ingredients linked to health effects of particular concern:

82% of children are exposed to one or more known human neurotoxins every week through their use of personal care products. Growth and development of the brain continues for many years after birth, leaving infants and young children uniquely sensitive to the effects of neurotoxic agents; in particular, the blood-brain barrier, which can protect the brain from many toxic chemicals, is not fully formed until a child is 6 months old (Grandjean 2006). Examples of neurotoxins in children's products include benzyl and isopropyl alcohols. Although limits have been set for these chemicals in food (FDA 2007), no mandatory limits are in place for cosmetics. The cosmetic industry safety panel found that the safety of benzyl alcohol in products that may be inhaled is unknown, and has not reviewed the safety of isopropyl alcohol. Survey findings show that products that may be used by children contain 82 neurotoxic chemicals altogether, raising particular concerns in light of recent warnings of evidence suggesting that developmental disabilities stemming from neurotoxic chemicals like those in children's products can be considered a "silent pandemic in modern society" (Grandjean 2006). Potentially neurotoxic agents with more limited toxicity data that are common in children's products include the preservative methylisothiazolinone, which was found to damage developing neurons in a study that exposed rat brain cells repeatedly to very low levels of this substance (He 2006), raising concerns with respect to children's exposures as well.

69% of children are exposed to one or more ingredients that can disrupt the hormone system every week through their use of personal care products. These ingredients include estrogen mimics called parabens, preservatives to which 91% of children are exposed according to our survey, and triclosan, a common antimicrobial chemical in liquid hand soap that can easily absorb into the body (Wolff 2007) and that preliminary studies show can disrupt thyroid growth hormones. Exposures to hormonally active chemicals are a particular concern considering some current health trends of significance in the U.S. population. For instance, 1 in 8 females in the U.S. will develop breast cancer in her lifetime, and risks are increased by exposures to estrogenic chemicals. Exposures to hormonally active chemicals may influence time to puberty; over the last 4 decades, the age at which girls in the U.S. begin menstruating has declined by a few months, while the age at which girls begin to develop breasts has declined by 1 to 2 years (Steingraber 2007). Additionally, a survey of 25,862 Americans that found over 10% of the population to have abnormal thyroid function (Canaris 2000) raises concerns with respect to children's widespread exposures to thyroid-disrupting chemicals in personal care products.

3.6% of children are exposed to one or more ingredients designated as known or probable human carcinogens by government health agencies, including coal tar in skin treatment shampoos, BHA in diaper cream, and silica in powders. Increasing rates of many childhood cancers, including leukemia, non-Hodgkins lymphoma, and specific brain and nervous system cancers (Ries 2007), provide a clear cause for alarm regarding exposure of babies and children to chemicals linked to cancer.