Environmental contaminants affect children differently than adults. Children generally eat more food, drink more water and breathe more air relative to their size and consequently may be exposed to relatively higher amounts of pollution. Children’s normal activities, such as putting their hands in their mouths or playing on the ground, also create opportunities for exposures to contaminants that adults don’t typically face. In addition, environmental contaminants may affect children disproportionately because their immune defenses are not fully developed and their growing organs are more easily harmed.

Children’s environmental health is important because children experience different:

Growth — Children, beginning in the womb and continuing through adolescence, are in a dynamic state of growth, with cells multiplying and organs developing at a rapid rate. In just the first four months of life an infant more than doubles its weight.

Absorption Rates — The rate at which children absorb nutrients during digestion may affect their exposure to toxicants. For example, children have a greater need for calcium and will absorb more when consumed. When lead has been swallowed, however, the body will absorb it in place of calcium. An adult will absorb 10 percent of swallowed lead, while a toddler will absorb 50 percent.

Metabolism — Because a child’s metabolic systems are still developing, their ability to expel toxins differs from adults. This difference is sometimes to the child's advantage, but more frequently they are not able to get rid of toxins and are more vulnerable to them. A fetus may be permanently damaged by exposure to a wide variety of chemicals, including lead, polychlorinated biphenyls, methylmercury, ethanol and nicotine, that can cross into its bloodstream through the placenta.

Behaviors — A child spends hours close to the ground where he or she may be exposed to toxicants in dust, soil and carpets as well as to pesticides in low-lying layers of air. Normal development includes a great deal of putting hands in mouths, providing another avenue for exposure to harmful things such as lead and pesticide residues. Children also spend more time outdoors and are often engaged in vigorous play, exposing them to potentially adverse effects from air particulates, ozone and other chemicals that pollute outdoor air.

Diets — Because children eat more fruits and vegetables and drink more liquids in proportion to their body weight, their potential exposure to harmful things (e.g. lead, pesticides and nitrates) when swallowed is greater. For example, the average infant’s daily consumption of six ounces of formula or breast milk per kilogram of body weight is equivalent to an adult male drinking 50 eight-ounce glasses of milk a day. Likewise, proportionate to its body weight, the average 1-year-old eats two to seven times more grapes, bananas, pears, carrots and broccoli than an adult.