Children's Health and Environment Fact Sheet

Children's Health and Environment Fact Sheet

Developmental Disabilities

November 2004

Summary

Developmental disabilities, the name given to a broad group of conditions caused by learning or physical impairments, affect around 17 percent of U.S. children under age 18.1 Mental retardation, autism, cerebral palsy and attention deficit hyperactivity disorder (ADHD) are included in this group of disorders. The rates for some of these conditions, such as autism and ADHD, have been climbing. Although the cause of many developmental disabilities is unknown, a combination of genetic and environmental factors is thought to play a major role. The majority of the social and economic costs that these conditions create falls on the states, which are faced with a growing number of children who require special education and care.

Key Issues

Research has found that some widespread contaminants, such as lead and mercury, can damage a child’s developing brain and nervous system. State governments have been working to reduce childhood lead exposure for years, and many are beginning to address the mercury problem. The role that the environment plays in developmental disorders is still unknown in many cases, although one-quarter to one-half of all developmental disabilities are thought to result from interactions between genes and the environment.³

Attention deficit hyperactivity disorder (ADHD)

Rates for ADHD, a disorder characterized by inattention, impulsiveness and hyperactive behavior, have risen during the past few decades—nearly 7 percent of children ages 5 to 17 have been diagnosed with the disease. Although some of the increase is probably attributable to disease awareness and diagnosis, some portion of the increase may be due to environmental factors.

Autism

Autism is a brain disorder that causes children to have difficulty communicating and socializing. Rates are climbing throughout the United States and in many other countries, including Australia, Japan and the United Kingdom.⁴ In California, the state Department of Developmental Services reports that autism cases have soared—doubling between 1987 and 1998 and doubling again in the four-year period between 1999 and 2003.⁵ According to the Autism Society of America, the annual cost for autism treatment is approximately $90 billion, a number that is expected to increase significantly during the coming decade.

Birth defects

One of every 28 babies born in the United States has a birth defect, the primary killer of children under age 1.⁶ Although scientists know that some birth defects are genetic and some are environmental—exposure to medications or alcohol during pregnancy is a known risk factor—the cause of 70 percent of birth defects remains unknown.⁷

The Role of Environment

Public health researchers have long been aware that childhood exposure to lead or mercury can have permanent, adverse effects on intelligence and that high levels of mercury can cause mental retardation.8 Research suggests that other common environmental chemicals—PCBs and possibly some pesticides—may cause developmental disabilities as well.¹⁰

Childhood exposures to environmental factors also may contribute to neurological disorders that occur later in life, such as Parkinson’s and Alzheimer’s disease. Scientist’s postulate that the result of these exposures may not appear until later in life, when the damage hinders the brain’s ability to cope with the aging process.¹¹

State Concerns

A rise in the number of children designated with ADHD, autism and learning disabilities has placed increasing pressure on state resources.

Concern about developmental disabilities has been especially strong in California, due to a documented increase in autism cases. The California Department of Developmental Services (DDS) reports that autism is the fastest growing caseload; it has quickly outpaced the growth of the general population—in 20 years autism went from 3 percent of the caseload to more than 30 percent. DDS estimates an additional $2 million in lifetime care costs for each additional case.

State Action

States have passed nearly 200 bills in the last five years to prevent children from being exposed to chemicals—such as mercury, lead and some pesticides—that cause or are suspected of causing developmental disabilities.

These bills range from eliminating mercury in con-sumer products to reducing pesticide use in schools and daycare facilities.

In May 2004, Senator Deborah Ortiz introduced Senate Bill 1168, the Healthy Californians Biomonitoring Project. The legislation, which passed the Senate but not the House, would have created a pilot program to monitor breast milk for environmental contaminants. It also creates pilot projects that monitor blood and urine for environmental exposures. Researchers would use the data to help determine whether certain contaminants influence disease.

Legislation to reduce children’s exposure to chemicals that may disrupt development includes Michigan H.B. 5154, enacted in March 2004, which requires that schools to adopt an integrated pest management program (an approach that focuses on non pesticide pest prevention) before pesticides can be used on the property. Rhode Island H.B. 5113, enacted in 2001, requires schools and daycare centers to notify parents before pesticides are used on school grounds.

Both the California and Washington legislatures are involved with phasing out brominated flame retardants, which may interfere with childhood development, according to some studies. While other states are considering the elimination of these flame retardants, EPA is working with chemical manufacturers to phase them out voluntarily.

On the Horizon

One area that is likely to assume importance in the future is environmental public health tracking. More states are likely to develop the practice of monitoring the population for exposure to chemicals and to improve the tracking of developmental disabilities. Tracking and exposure information will help researchers to better understand the causes of developmental disabilities.

Resources

For more information about developmental disabilities and other enviromental health issues, visit NCSL online. Resources include a new video and book on children’s health and the environment and many other publications. Visit www.ncsl.org/programs/esnr/toxics.htm or call (303) 364-7700, ext. 1341.

Notes

1. Centers for Disease Control and Prevention, Developmental Disabilities Web page, www.cdc.gov/ncbddd/dd/, 2004.

2. Sara B. Miller, “Demand on special ed is growing” Christian Science Monitor, (August 24, 2004).

3. Ted Schettler, “Toxic Threats to Neurologic Development of Children,” Environmental Health Perspectives 109, Supplement 6 (December 2001): 813-816.

4. Department of Developmental Disabilities, California Health and Human Services Agency, Autism Spectrum Disorders (Sacramento, CA: April 2003).

5. Ted Schettler, “Toxic Threats to Neurologic Development of Children.”

6. Centers for Disease Control and Prevention, Web page, http://www.cdc.gov/ncbddd/bd/bdres.htm, 2004.

7. Ibid.

8. K. S. Crump et al., “Influence of prenatal mercury exposure upon scholastic and psychological test performance: benchmark analysis of a New Zealand cohort” Risk Analysis 18, 6 (1998): 701-13.

10. P. Mendola et al., “Environmental factors associated with a spectrum of neurodevelopmental deficits,” Mental Retardation and Developmental Disabilities Research Review 8, No. 3 (2002): 188-97.

11. BK Barlow, et al., “A fetal risk factor for Parkinson’s disease,” Developmental Neuroscience 26, 1 (Jan.-Feb. 2004): 11-23.

This publication was developed under a cooperative agreement with the U.S. Environmental Protection Agency (EPA Assistance Number CH 82848501). EPA does not endorse any products or commercial services mentioned in this publication.