The quality and design of a child’s physical environment can cause or prevent illness, disability and injury; therefore a high-quality environment is essential for children to achieve optimal health and development. While pediatricians are accustomed to thinking about health hazards from toxic exposures, much less attention has been given to the potential for adverse effects from “built environments” such as poor-quality housing and haphazard land-use, transportation, and community planning. In fact, children spend little time in natural environments compared to the time they spend indoors and in neighborhoods. .