This page updated March 24, 2003.
Children may be more vulnerable to harmful
impacts from air pollutants than adults for several reasons. They breathe more air than do adults, relative to
their body size, and have greater metabolic growth requirements. Their activities create exposure scenarios that
are unique for children. Children spend 86 percent of their time indoors, on average. The home is the primary location
where they spend time; time at school accounts for most of their remaining time indoors. Often children's activities
bring them into close proximity with indoor sources. For example, young children spend more time on the floor where
they are more likely to inhale particles stirred up by activities.