Understanding Exposures in Children's Environments
EPA scientists and their partners provide key research outcomes for understanding and reducing environmental risks to children's health.
Anyone who has ever watched a toddler barreling around knows that trouble lurks around every corner. Young children crawl around on the floor, play in dirt, and put just about anything they can into their mouths, whether it's a cookie from the floor, a plastic toy, or a dust-covered curiosity grabbed from under the sofa. These types of behaviors put kids at risk of being exposed to something toxic.
By developing better science-based knowledge about how kids are exposed to harmful things in their environments, it's possible to reduce their risks and take action to better protect them. That's the goal of EPA's childhood exposure research.
EPA's work to understand childhood exposure began shortly after the Agency was established in 1970. The early studies focused primarily on how young people might encounter pesticides during their daily routines.
EPA is using the information available in the Exposure Factors Handbook, the Child-Specific Exposure Factors Handbook, EPA exposure assessment guidelines, and other sources to develop the EPA-Expo-Box, a compendium of exposure assessment and risk characterization tools that provide step-by-step guidance for conducting an exposure assessment. EPA-Expo-Box will also include links to exposure assessment databases, models, and references – all in a user friendly format organized by the various components of exposure assessment.
EPA-Expo-Box will provide one stop shopping for the latest tools and techniques for exposure assessment. It will become a critical tool for EPA and beyond by providing information to support scientifically defensible exposure and risk assessments to inform decisions to protect human health.
"Products or behaviors that parents think are perfectly acceptable might come with unintended consequences," said Nicolle Tulve, PhD, a research physical scientist at EPA. "In all our research, we're focused on day-to-day behavior; we want to understand what exposures are like for kids leading typical lifestyles."
One important way that EPA has increased the understanding of children's exposures is by developing the Child-Specific Exposure Factors Handbook, which provides information on various physiological and behavioral factors commonly used in assessing children's exposure to environmental chemicals. It is used by scientists, economists, health assessors, and others within and outside EPA conducting exposure assessments, a critical step in identify human health risks—including those to children's health—from exposure to chemical contaminants and other environmental stressors.
To conduct an exposure assessment, scientists need to understand aspects of exposure, such as how much air a person breathes or how much water a person drinks on a daily basis. EPA's Exposure Factors Handbook, a standard reference tool, helps by summarizing information and recommendations on factors relevant to exposure assessments. Recently updated in 2011, it provides the most accurate and relevant information on factors ranging from the intake of fruits and vegetables to consumer product use.
But because a child's exposure differs from an adult's exposure, EPA developed the Child-Specific Handbook in 2008. The child-specific handbook takes into account that children typically have different diets, higher inhalation rates per unit of body weight, and come into contact with contaminated surfaces when they play close to the ground. Understanding these differences is critical for evaluating potential environmental hazards from pollutants and will help protect children from dangerous exposures.
"By understanding exposure, we can help parents and other caregivers make more informed decisions about how to protect their child's health," explained Tulve.
Children's Health Research in Action
EPA’s children’s exposure research helps to paint a picture of how an environmental contaminant might affect children’s health. This research provides a better understanding of the potential sources, routes, pathways, and exposure factors that are important for children’s exposures, supporting better and earlier decisions on when and how to reduce or eliminate environmental exposures that are potentially harmful to children.
Some of EPA’s current and past children’s exposure research includes:
- EPA recently partnered with the U.S. Consumer Product Safety Commission (CPSC) to develop tools, approaches, and protocols they need for determining if nanosilver is released from children's consumer products under real-world conditions, thus making it potentially available to children.
Preliminary study results, conducted on 13 products containing nanosilver, indicate that the silver levels to which children may potentially be exposed during normal product use is low.
- EPA scientists recently used the Stochastic Human Exposure and Dose Simulation Model for multimedia pollutants (SHEDS-Multimedia), an innovative modeling tool used to estimate total exposures from chemicals encountered in everyday activities, to estimate soil and dust ingestion exposures of children ages three to six years.
Researchers found that on average, 60 percent of total soil and dust ingestion among children ages 3 to 6 years, is from soil ingestion, 30 percent is from dust on hands, and 10 percent is from dust on objects.
EPA and University of California Davis scientists are collaborating to conduct the Study of Use of Products and Exposure Related Behaviors (SUPERB), which examines human behaviors and how they influence exposure to chemicals in homes. As part of the research, EPA scientists have developed methods for analyzing selected types of chemicals found in household dust, surface wipes, passive air collection and cotton garment samples. Read more on SUPERB.