Children have disproportionately heavy exposures to environmental toxicants. Pound for pound of body weight, children drink more water, eat more food, and breathe more air than do adults. The health implication of these findings is that children will have substantially heavier exposures than adults to any toxicants that are present in water, food, or air.
Children’s metabolic pathways, especially in the first months after birth, are immature. Children’s ability to metabolize, detoxify, and excrete many toxicants is different from that of adults. In most instances, they are less able to deal with toxic chemicals and thus are more vulnerable to them. Children undergo rapid growth and development, and their evelopmental
processes are easily disrupted. Many organ systems in infants and children undergo very rapid change prenatally as well as in the first months and years after birth. These developing systems are very delicate and are not well able to repair damage that may be caused by environmental toxicants. Because children have more future years of life than most adults, they have more time to develop chronic diseases triggered by early exposures. Many diseases are triggered by early exposures. Those that are caused by toxicants in the environment are now thought to arise through stages that require years or even decades to evolve from earliest initiation to actual manifestation of disease. Carcinogenic and toxic exposures sustained early in life, including prenatal exposures, appear more likely to lead to disease than are similar exposures encountered later.