Children may be exposed to pesticides in their diet. A pesticide is any substance intended to destroy, prevent, or repel pests, such as insects, weeds, fungi, and rodents. The term pesticide includes numerous types of substances designed for different purposes. For instance, herbicides kill unwanted plants, fungicides kill fungi, rodenticides kill rodents, and disinfectants kill microorganisms. Although many pesticides are synthesized from petroleum, some are derived from natural origins.

Depending on the dose, pesticides may cause a range of harmful health effects and may accumulate in ecosystems. Among the health effects reported are cancer, acute and chronic injury to the nervous system, lung damage, reproductive dysfunction, and possibly dysfunction of the endocrine (hormone) and immune systems.

Children are at greater risk of pesticide exposure than most adults. Pound for pound of body weight, children not only breathe more, eat more, and have a more rapid metabolism than adults, but also they play on the floor and lawn where pesticides are commonly applied. Children have more frequent hand-to-mouth contact as well.

Children may be exposed more heavily to certain pesticides because they consume a diet different than adults. For instance, children typically consume larger quantities of milk, applesauce, and orange juice per pound of body weight. This means their exposure to any pesticide residues in these foods may be higher than that of adults. Children generally are more susceptible than adults to environmental toxics because they are growing and developing. Also, their enzymatic, metabolic, and immune systems are immature, allowing in some cases for less natural protection than that of adults

Endocrine disruptors are chemicals that may mimic or disrupt the action of naturally occurring hormones. Many of these substances have estrogenic effects. Increasing scientific and public attention has been focused on substances that have the potential of disrupting the endocrine systems of wildlife, laboratory animals, and possibly humans. Disruption of the endocrine system may occur in various ways. Some chemicals may mimic a natural hormone, in effect fooling the body into over-responding to the hormone. Other chemicals may block the effects of a hormone in parts of the body normally sensitive to it. Still others may indirectly stimulate or inhibit the endocrine system, leading to overproduction or underproduction of hormones. Endocrine disruptors may also play a role in reproductive cancers. The primary route of exposure is ingestion.

Scientific questions remain, however, about which chemicals are involved in disruption of the endocrine system and how children may be exposed to those chemicals. It is not yet known whether health effects similar to those observed in laboratory animals are produced in humans, and what methods are best for testing for these effects. EPA is investing significant resources to find answers to these questions.

PCBs and dioxins produce a number of toxic effects in animals. They have been linked to such health concerns as decreased gestational age, lower birth weight, depressed immune responses, impaired mental development, and growth retardation. Dioxin is considered by EPA to be a known human carcinogen and as such may have adverse effects on children that do not become apparent until many years after exposure occurs. However, no direct causal relationship has been established between PCB exposure and human health effects.

Each environmental or occupational disease identified should be considered a potential sentinel health event witch may require follow-us activities to identify the exposure source, one can prevent continued exposure to the initial patient and any other individual involved.

In comparison to adults, children may be at greater risk from pesticide exposure due to growth and developmental factors. Consideration of fetal, infant, toddler or children characteristics is helpful in an exposure evaluation: physical location, breathing zones, oxygen consumption, food consumption, types of food consumed and normal behavioral development. Furthermore, transplacental absorption and breast milk may pose additional routes of exposure.

For these high-risk group, the exposure history should include specific questions about the agricultural work being done, for example:

• Are pesticides being used at home or work?
• Were the fields wet when you were picking?
• Was any spraying going on while you were working in the field?
• Do you get sick during or after working in the fields?

The use of pesticides in the residence and taking home agricultural pesticides or contaminated work clothes that are not properly separated from other clothes may pose hazards for other household members as well.