Over the past fifty years, the number of reported childhood disabilities has steadily increased and the nature and consequences of disability have changed drastically. Prior to 1960, the poster child for childhood disabilities would have been a child with polio, wearing leg braces and using crutches for support. Today’s poster child could be a child with autism. Where the pre-60s child wore his disability for the world to see, in many cases today’s child experiences his disability internally. Over the past several decades, predominant childhood disabilities have shifted away from physical disorders toward mental health disorders. (Future of Children: Childhood Disabilities)

Much public attention and many resources are focused on medical research to identify risk factors and mitigate symptoms of disability for individual children. However, Stephen Rauch and Bruce Lanphear, in their chapter “Prevention of Disability in Children: Elevating the Role of the Environment,” argue for a broader focus on environmental influences that put entire populations at risk. “Identifying and eliminating or controlling environmental risk factors that incrementally increase the prevalence of disability is the key to preventing many disorders,” they write.

When seeking to prevent disability, there are three levels that need to be considered. Primary prevention seeks to keep disabilities from developing. Secondary prevention utilizes methods of screening and early detection to identify problems before they can do “too much damage.” Tertiary prevention focuses on restoring health and function to people who have already developed a disability. Tertiary and secondary prevention are the primary efforts of the clinical community. But in order to reduce the prevalence of disability in the population, primary prevention is essential.

The causes of many disabilities in childhood are complex and result from the interplay of environmental risk factors and genetic susceptibility. Purely genetic and purely environmental disabilities exist, but they are rare. Children are particularly vulnerable to environmental stressors; they pass through several delicate developmental stages and, pound for pound, they eat and breathe more environmental contaminants than adults. An exposure that is harmless in adults can have a dramatic effect when it occurs during fetal development or early childhood.

One example of an environmental risk for disabilities in children is lead in house paint. Lower IQ and ADHD in children have both been linked back to lead as has criminal behavior in adulthood. A cost-benefit analysis of requiring lead based paint to be removed concludes that every $1 spent to reduce lead hazards in housing would produce between seventeen and two hundred twenty one dollars in benefits by reducing screening and treatment for lead toxicity, ADHD treatment, and special education.

(Rauch and Lanphear Future of Children: Childhood Disabilities)

In a long awaited move, the CDC recently cut the threshold for lead poisoning. This new lower threshold “means public health agencies have a bigger job to screen children for lead and to prevent exposure in the first place,” said Lanphear in an interview with John Ryan of Seattle station KUOW “The new standard from the Centers for Disease Control and Prevention nearly doubles the number of children considered to have lead poisoning. Now, one out of 40 American kids has what’s deemed a dangerous level of lead in their blood, reported Northwest public radio.” (http://www.nwpr.org/post/cdc-cuts-lead-poisoning-threshold)

This change in lead level standards is just one example of how our regulations and knowledge about environmental risk factors changes over time. In the face of such changes, it makes sense to consider a preventive approach that shifts the entire population’s health curve in a positive direction. As Issue Editors Janet Currie and Robert Kahn summarize in the introduction to Children with Disabilities, “the heart of [Rauch/Lanphear’s] argument is that societal choices can shift the curve of child health outcomes to increase the probability that some children will be moved from a nondisabled to a disabled state. Exposure to chemicals in the environment, for example, may decrease the attentiveness of all children, but in a subset of more vulnerable children, the exposure may lead to symptoms and impairment that warrant an ADHD diagnosis. The implication is that society should pay attention to shifting the entire distribution of health outcomes in a positive direction and that doing so will reduce the toll of childhood disability. Such a public health focus on prevention is a useful comple­ment to the usual medical focus on improving technology or the quality of medical care for children who already have disabilities.”

For more information, read our Children with Disabilities volume: www.futureofchildren.org.