A new, comprehensive survey of day care centers by University of California, Berkeley, researchers found that, overall, the environmental quality in child care settings was similar to other indoor environments, but that levels of formaldehyde and several other contaminants exceeded state health guidelines. Cleaning- and sanitizing-related chemicals were also present in the air, and sometimes at higher levels, than in comparable studies on homes.
The study, funded by the California Air Resources Board (CARB), is
the first detailed analysis of environmental contaminants and exposures
for California day care centers. It covered 40 early childhood education
facilities in Alameda and Monterey counties. Researchers found that 35
of the centers, or 87.5 percent, had levels of formaldehyde greater than
9 micrograms per cubic meters over eight hours, which is above
California’s guideline for safe exposure.
Formaldehyde, a known respiratory irritant and a listed carcinogen
under California’s Proposition 65, “The Safe Drinking Water and Toxic
Enforcement Act of 1986,” is commonly found in the glues used in
pressboard furniture and laminated wood. It is also in many paint,
clothing and cosmetic products, and is emitted from combustion sources
such as wood burning and gas stoves.
“Children are more vulnerable to the health effects of environmental
contaminants, and many small children spend as much as 10 hours per day,
five days a week, in child care centers,” said study lead author Asa
Bradman, associate director of the UC Berkeley Center for Environmental
Research and Children’s Health (CERCH). “We wanted to establish the
baseline levels of environmental exposures in these early child care
settings, and to provide information that could be used for any
necessary policy changes.”
The 40 centers in the study were located in a mix of urban, rural and
agricultural areas, and served a total of 1,764 children. The
researchers collected air and floor dust samples when the children were
present and tested for a broad array of chemicals. Particles in the air
were also measured, including ultrafine particles, which are extremely
small and can be inhaled deeply into lungs.
The California Air Resources Board has been developing and
implementing regulatory programs to reduce emissions of volatile organic
compounds from consumer products used in homes and institutions. In
2008, under its Toxic Air Contaminants Program, the board implemented
new rules to reduce formaldehyde emissions from building materials and
furniture made from pressed wood, the biggest source of formaldehyde in
Although furnishings and building materials that emit formaldehyde
can still be sold in California until the regulation is fully
implemented, there are many new pressed wood products on the market that
emit little or no formaldehyde. These low emitting products are labeled
as CARB Phase 2 (P2). Composite woods products labeled as Ultra Low
Emitting Formaldehyde (ULEF) or No Added Formaldehyde (NAF) have the
lowest emissions profiles.
Formaldehyde can also form when chemicals from cleaners and
sanitizers, such as d-limonene, react with ozone and other compounds in
the air. D-limonene is extracted from citrus peels to give cleansers,
perfumes and other products a lemon-orange scent.
Ensuring proper ventilation can help reduce contaminant levels, the study authors said.
“These findings show that cleaning and sanitizing products impact air quality in child care settings,” said Victoria Leonard, a scientist at
UC San Francisco’s Institute for Health and Aging who is leading a
program to promote healthier product choices in child care, and who was
not involved in data analysis for this study. ”Given that many young
children have asthma or other respiratory problems, this study offers
strong evidence to select safer cleaning products that have less
In some centers, levels of ultrafine particles increased by up to a
thousandfold when cooking appliances were turned on. However, while
ultrafine particles have been associated with serious health impacts,
their health effects are not well understood, and there are no
guidelines for safe levels. And since formaldehyde can also be emitted
from gas stoves, the study authors advised using a range hood and fan
when cooking to reduce particle and formaldehyde levels.
The researchers also detected other chemicals, including phthalates
(found in plastics), flame retardants, pesticides and perfluorinated
compounds (found in Teflon and stain resistant carpets).
“For most of those chemicals, however, there has not been adequate
toxicity testing, so we cannot evaluate the health risks,” said
“This study reinforces the need for child care providers to remain
alert to environmental concerns,” said Hester Paul, director of the
EcoHealthy Child Care program for the Children’s Environmental Health
Network in Washington, D.C.
“It is important to identify areas where improvement is needed, and
this study has done that,” added Paul, who is not affiliated with this
study. “Fortunately, many local, state and non-profit agencies are
working to give child care providers the tools they need to address
Other study authors are Fraser Gaspar, Rosemary Castorina, Elodie
Tong-Lin and Thomas McKone at UC Berkeley’s School of Public Health, and
Randy Maddalena at the Lawrence Berkeley National Laboratory.