the United States under age eighteen suffer from one or more learning, developmental,
or behavioral disabilities. According to conservative estimates, attention deficit hyperactiv-
ity disorder (ADHD) affects 3 to 6 percent of all schoolchildren, though recent evidence
suggests the prevalence may be as high as 17percent. The number of children taking the
drug Ritalin for this disorder has roughlydoubled every four to seven years since 1971
to reach an estimated 1.5 million. Learning disabilities alone may affect approximately 5
to 10 percent of children in public schools. The number of children classified with learn-
ing disabilities in special education programs increased 191 percent from 1977 to 1994.
Pesticides
Animal tests of pesticides belonging to the commonly used organophosphate class
of chemicals show that small single doses on a critical day of development can cause
hyperactivity and permanent changes in neurotransmitter receptor levels in the brain.
Chlorpyrifos, one of the most commonly used organophosphates, decreases DNA
synthesis in the developing brain, resulting in deficits in cell numbers. Some pyre-
throids, another commonly used class of pesticides, also cause permanent hyperac-
tivity in animals exposed to small doses on a single critical day of development.
Children exposed to a variety of pesticides in an agricultural community in Mexico
show impaired stamina, coordination, memory, and capacity to represent familiar
subjects in drawings.
These trends may reflect true increases, improved detection, better reporting,
improved record keeping, or some combination of these factors. Whether new or
newly recognized, these statistics suggest a problem of epidemic proportion.^12
The JAMA Study
A recent widely reported study in theJournal of the American Medical Association
underscored the risks of pesticide use in and around the nation’s schools. Analyzing
2,593 reported pesticide poisonings in schools and childcare centers between 1998
and 2002, the study reported several troubling findings: incidence rates among chil-
dren increased significantly from 1998 to 2002; drifting pesticides applied off site
were responsible for 31 percent of reported poisonings; and insecticides and disinfec-
tants were the pesticides most frequently at fault. The study’s authors noted that no
federal requirement limits pesticide exposures at childcare centers or elementary or
secondary schools. They stressed their results should be considered low estimates of
the magnitude of the problem because many cases of pesticide poisoning are likely
not reported to surveillance systems and poison control centers.
The study examined state surveillance data from the National Institute for Occupa-
tional Safety and Health’s Sentinel Event Notification System for Occupational Risks
pesticides program, from the California Department of Pesticide Regulation, and
from a national database of calls made to poison control centers compiled by the
American Association of Poison Control Centers’ Toxic Exposure Surveillance Sys-
tem. The study reported incidence rates of pesticide-related illness of 7.4 cases per
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