The need for physical protection, safety, and regulation-like the need for ongoing relationships-is self-evident to many educators, parents, and policymakers.

One of the most important preventable challenges to our children's physical safety and protection is toxic substances in their environment. Debates regarding how much of a particular toxic substance is necessary to harm a child (or adult) tend to obscure two facts that demand our immediate attention. Many toxic substances that affect the central nervous system are in drinking water, soil, air, and areas inside the home and school. Children, because of their smaller bodies, rapid growth, and expectable pleasure in playing on the ground or floor while exploring with their hands and mouths, can absorb many of these toxic substances in relatively higher proportions.

Protecting our children from exposure to chemicals like dioxin is a far greater challenge than we might imagine. Exposures occur prenatally through what the mother has ingested and breathed, and then continue after the baby is born through breast milk or through general environmental exposure. We have to consider that these substances may be contributing culprits, along with other factors, in the increasing incidence of learning, attentional, and several developmental problems.

There are many categories of toxins commonly found in the environment. In addition to the well-known risks of lead, alcohol, and tobacco by-products, as well as patterns of substance abuse, a number of toxins can be found in products used for lawn care (herbicides), insect control (pesticides), and house-cleaning and painting products (volatile organic compounds). As stated earlier, children, because they enjoy playing on lawns and floors and sometimes explore with their mouths, can take in through skin, breathing, or eating much more of these toxins for their size relative to adults.

The fact that toxic substances have contaminated breast milk, water, soil, and air should be cause for alarm and collective corrective action. Although there are a few things that teachers, parents, and children can do in the interim, such as limiting the amounts of animal fats in the diet (animal fats tend to store these chemicals), not eating fish or shellfish from polluted bodies of water, and avoiding pesticides, herbicides, and other toxic substances (especially in relationship to where children are playing)-a major goal must be to reduce and remove this major health hazard.

Concern about these toxic exposures and other threats is compounded by the fact that even the most modest damage to the functioning of the human central nervous system can result in an escalating cascade of learning, intellectual, emotional, and social problems. For example, the children who are exposed to toxic substances (alcohol, tobacco, drugs, lead) in utero have a high likelihood of being born with nervous systems that are either over- or underreactive to basic sensations such as touch and sound. They also tend to have difficulties with motor planning and sequencing, i.e. planning and carrying out actions. Any one of these factors can increase the tendency toward learning problems, impulsivity, antisocial behavior, and difficulties with forming peer relationships, reading social cues, and even organizing thinking and sustaining a sense of reality. In situations where these compromises are coupled with even modest degrees of family or environmental stress, there is a much higher likelihood of severe problems by the time the child is an adolescent. If the early compromises to the central nervous system result in underreactivity to touch, sound, and pain, and therefore lead to sensory craving, increased activity, and risk taking, and this pattern is coupled with neglectful, punitive, or abusive environments, there is a high likelihood of antisocial behavior (often beginning with conduct problems during childhood).

In such situations, corrective environmental experiences would provide sustained nurturance and empathy; persistent gentle, but firm, limits; lots of work at planning and organizing behavior; anticipating consequences of actions; and reflecting on-feelings.

Not all threats from the social environment are so clear or extreme. A recent study by the Kaiser Foundation revealed mat children were spending five-plus hours a day in front of TV or computer screens. We have not sufficiently studied the impact of such passive, repetitive perceptual activities on children, but from what we know about the human nervous system, it is reasonable to raise serious questions about their impact on attention, learning, and coping. In contrast to screen time, the dynamic interactions with other children and adults seem to enhance learning.

Many parents, physicians, teachers, and policymakers are asking: Why are we seeing more children with problems of attention, impulse control, language, learning disabilities, unstable moods, and pervasive developmental disorders affecting relating, communicating, and thinking? If we look at the possibilities, we can identify a list of factors, each one of which may contribute in combination with some of the others and genetic susceptibility. For example, exposure to toxins or extreme stress may make children more vulnerable to middle ear infections or allergic or autoimmune reactions, which may increase the risk for developmental problems. Many of these factors have in common their effect on aspects of central nervous system regulation involving reactivity to sensations (sound, touch, movement, pain), the capacity to process and comprehend those sensations (language, visual-spatial thinking), and the capacity to plan and sequence actions (problem-solving, executive functions). When any of these regulatory capacities are compromised, the child's behavior may stress his or her caregivers and create the potential for worsening problems.

We therefore have to consider how to wage a successful public health and education campaign on the familiar suspects.

When we consider what's at stake in terms of the future and the cost to individuals and society for every child whose nervous system is not functioning well, we realize that we must take a much bolder approach than we have been using. The physical protection and care of infants and young children and families have not been a high enough priority. A child's basic right to physical protection and care must be the foundation on which all other effects are built.