Health: Fetuses and young children in farm areas are at highest risk,
research suggests, with intelligence, motor skills and personalities
By MARLA CONE
Los Angeles Times Environmental Writer
Monday, March 15, 1999
Children exposed to pesticides in the womb or at an early age may suffer
permanent brain defects that could change their lives by altering their
behavior and their ability to do everything from drawing a picture to
catching a ball, according to new scientific research.
Widely used pest-killing chemicals, in amounts routinely found in the
environment in farm areas, seem to be capable of skewing thyroid hormones,
which control how the brain of a fetus or young child develops, according
to a study published today.
Scientists say the study and other recent research support an emerging
theory that pesticides may exact a toll on the intelligence, motor skills
and personalities of infants, toddlers and preschoolers.
"Data suggest that we may be raising a generation of children with learning
disabilities and hyper-aggression," said Warren Porter, a University of
Wisconsin professor of zoology and environmental toxicology.
Porter's study, published today in the journal Toxicology and Industrial
Health, shows that a common mix of insecticide, herbicide and fertilizer
found in drinking water altered the thyroid hormones of young mice. It also
changed their aggressiveness--measured by attacks on other mice--and
suppressed their immune systems.
Although a study of mice alone is not overly compelling, the theory is
bolstered by recent research on human beings.
In tests in the state of Sonora, Mexico, scientists found striking
differences in hand-eye coordination and other mental and physical skills
when comparing Yaqui Indian preschoolers in an agrarian region with those
in adjacent foothills where no pesticides are used.
Four- and 5-year-olds living in the farm valley had trouble performing a
variety of simple motor skills--drawing stick figures, catching a 12-inch
ball from almost four yards away and a tennis ball from more than a yard
away, and dropping raisins into a bottle cap from a distance of six inches.
They also had poorer memory skills and stamina, were more prone to physical
aggression and angry outbursts, and were less sociable and creative while
playing. Farm and household pest-killers are widely used there, and high
levels of multiple pesticides have been found in the cord blood of newborns
and the breast milk of mothers in the area.
Another study, in rural western Minnesota, found increased birth defects in
children conceived during the spring growing season.
Most of the new research detects problems in agricultural
communities--places found not just in rural regions but also in more
urbanized areas, including Southern California. No one knows yet what it
might mean for people who consume small traces of the chemicals in their
food. Earlier this month, Consumers Union reported that many fruits and
vegetables contain concentrations of pesticides that may be unhealthful
The new hormone studies add to a growing body of research from around the
world suggesting that dozens of commonly used pesticides and other
chemicals mimic the hormones that control sexual and neurological
Called endocrine disruption, this is arguably the most controversial
environmental issue of the past decade.