• Relative to their body weight, children eat, breathe, and drink more than adults do. So children take in higher concentrations of any toxins in their food, water, or air.
• As organs develop, they are more likely to be damaged by exposure to toxins.
• The ways that toxins are removed from the body are not fully developed in children.
• Children spend more time outdoors, where they may be exposed to outdoor air pollution and ultraviolet radiation.
• Children do more intense physical activity, causing them to breathe air pollutants more deeply into their lungs.
• Young children tend to put their hands, dirt, or objects into their mouths.

Source: Office on Women’s Health in the U.S. Department of Health and Human Services.