Every day across the country, parents place their newborn babies and infants on crib mattresses to sleep for 12 or more hours per day. What many parents don't know is that on the surfaces of some of these crib mattresses are toxic and endocrine-disrupting chemicals that are in close proximity to an infant's breathing zone and sometimes in direct contact with its skin.
Ongoing research in our laboratory at The University of Texas at Austin indicates that chemicals known as volatile organic compounds (VOCs), as well as potential endocrine-disrupting chemicals, are emitted from crib mattresses. Experiments have also clearly shown that the heat given off by an infant's body greatly increases emissions of many of these chemicals from mattresses and also serves to transport these same chemicals to the infant's breathing zone by affecting air flow patterns across the mattress and around the infant's body. What this means is that the body of an infant lying on a crib mattress actually promotes increased exposure to whatever toxic chemicals exist in the mattress. The levels of these chemicals in the breathing zone of an infant lying on a mattress are often many times as great as in the breathing zone of someone else standing in the middle of the room where the mattress exists. In effect, the infant is within a "personal cloud" of chemicals emitted from the mattress on which it rests.
An infant's low body mass and developing organs and immune system make it particularly vulnerable to the adverse effects of exposure to many chemicals that may not be of great concern to adults. And there is mounting evidence that demonstrates that exposure to a range of toxic chemicals exerts harmful effects that can last a lifetime. For example, certain classes of chemicals act as endocrine disruptors, blocking natural hormones from performing vital functions in an infant's body. These and other chemicals lead to increased risk of childhood cancer, infertility and other adverse effects on reproductive health, increased pulmonary infections, risk of allergic disease and asthma.
Not all mattresses are the same, and there are tradeoffs inherent in mattress selection. We analyzed 20 new and old crib mattresses containing either polyurethane foam or polyester foam. More than 30 VOCs were found, and new crib mattresses released on average about four times as much VOCs as old mattresses. However, some older mattresses contain harmful flame retardants that are now being phased out in the United States. The amount of specific chemicals released from a mattress is also influenced by the type of foam material in the mattress and the presence of a mattress cover layer. Many VOCs released from polyurethane foam are used during foam production and are not released from polyester foam. Crib mattress covers may act as barriers to chemicals originating from mattresses, but they can also be a significant source of chemicals associated with plastic products.
The sleep microenvironment and its role in adversely affecting infant health deserves much more attention. Public awareness is a start, but for parents, figuring out which mattresses are safest for children and which to avoid can be difficult. Becoming educated on the subject and asking the right questions when shopping for a crib mattress are important. Current regulations do not require adequate premarket safety testing, and disclosure of chemicals used in crib mattresses is voluntary. Mattress and bedding manufacturers should step up, increasing transparency of what is contained and emitted from their products, and helping to reduce exposures to those most vulnerable to toxic chemicals in their products. If not, a bill to reauthorize and modernize the Toxic Substance Control Act (TSCA) via the Chemical Safety Improvement Act is pending in Congress and could be used to reduce or eliminate chemicals that are most likely to cause both short- and long-term harm to infants and children. In 1976, the TSCA mandated the Environmental Protection Agency to protect the public from "unreasonable risk of injury to health or the environment." If we do not protect those most vulnerable to risk of injury to health, whom will we choose to protect?
Ying Xu is an assistant professor of building energy and environments in the Department of Civil, Architectural and Environmental Engineering in Cockrell School of Engineering at The University of Texas at Austin. Her research focuses on understanding the relationships among chemical sources, indoor environments and human health.
A version of this op-ed appeared in the Austin American Statesman.