OP pesticide. In 2001, the EPA decided to cancel, phase out, or continue under
time-limited registrations the crop uses of azinphos methyl and phosmet. In addition,
the EPA and registrants will voluntarily ban certain uses of propargite. The goal of
these and other regulatory actions against individual OPs is to reduce cumulative OP
risk to a safe level.
The EPA released a preliminary cumulative risk assessment for OPs in December
2001 and revised cumulative OP risk assessment in June 2002. However, final OP
cumulative risk assessment is not yet complete. As the EPA collects more data, revised
cumulative OP risk assessment might produce lower risk estimates, indicating that
pesticide residue levels are reasonably certain to be safe (as farmers and pesticide man-
ufacturers contend). On the other hand, data might support the view of public health
advocacy groups that indicates that, despite regulatory actions, children are exposed
to unsafe levels of OPs on pears, apples, grapes, and peaches, risking damage to
developing brains and nervous systems.^40
The ‘‘Body Burden’’
Just as we don’t tend to think about the invisible, we seldom consider the accumu-
lation of years of pesticide exposure in our bodies. While some sources believe the
benefits of pesticides to human nutrition outweigh any potential health risks, research
suggests otherwise.
When veteran journalist Bill Moyers had his blood and urine tested as part of a
Mount Sinai School of Medicine study of pollutant loads in the human body, eighty-
four distinct chemicals were found, including some that had been banned more than
a quarter of a century earlier. This chemical ‘‘body burden,’’ as it is medically known,
is even more insidious for children, whose developing bodies and brains are more
vulnerable than those of adults. A 2005Journal of the American Medical Association
study found that the incidence of illness linked to pesticide use in and around U.S.
schools is rising. Organophosphates, the same class of insecticides detected in
Moyers’s blood, were most frequently responsible for these poisonings.^41
Pesticides and the Enzyme PON-1
Pesticide regulation might not be strict enough to protect newborns and infants. A
2006 University of California study of 130 mothers and their children in California’s
Central Valley, a large agricultural area, revealed that a natural enzyme that breaks
down toxicants (including commonly used pesticides) varies to such a degree that
some young people may be virtually defenseless against many chemicals. This
enzyme, PON-1, is one of hundreds of important enzymes that control the body’s
metabolism. Other studies have shown that PON-1 is linked to protection against
neurodegenerative or cardiovascular diseases.
The study was designed to examine the protective levels of PON-1 against OPs. In
pesticides, OPs attack the nervous systems of insects. Two common OPs, diazinon
and chlorpyrifos, were widely used before they were restricted from most household
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