How Pesticides Affect Our Health
Pesticides and risks to children
Children and tolerance
“For fetuses, infants and children alike, subclinical developmental neurotoxicity is the major threat posed by exposure to pesticides….Because these injuries cannot be reversed medically, prevention of exposure must be emphasized.”
Dr. Philip Landrigan, Professor of Pediatrics and Director
of the Center for Children’s Health and the Environment,
Mt. Sinai School of Medicine, New York
Studies on children and pesticides show that the risks for children and adults might be very different.
On the whole, children have a lower tolerance and are more sensitive to the effects of pesticides because:
- The enzymes and organs that rid their body of toxic chemicals are not fully developed.
- They are smaller and lighter than adults, so they receive a larger dose per exposure than adults.
- Their breathing zone is much lower to the ground than an adult’s, so children inhale a higher dose of pesticides that settle closer to the ground.
- They explore their environment with their hands and mouths , so they’re more likely to transfer pesticide residues directly into their bodies.
One study showed that hand-to-mouth transfer of pesticide residues possibly accounted for about half of the pesticides that the children absorbed from playing on a lawn treated with chlorpyrifos. Children are also more likely to be exposed to pesticide residues tracked indoors on shoes and feet.
Traces of pesticides in urine samples
Researchers testing urine samples for pesticide levels found that most people in the United States (greater than 80% in some samples) have been recently exposed to pesticides and pesticide metabolites.
Two separate studies of children in Minnesota and in Washington State identified breakdown products of some organophosphate pesticides in the urine of most children.
Pesticides like chlorpyrifos normally break down and are eliminated from our bodies within three to six days. The amounts detected in urine are usually very small and aren’t associated with adverse health effects in individual children. However, researchers caution that we don’t have all the answers about long-term effects of such exposures where children are concerned.
Brain and nervous system development
Since their brains are still growing, children are at greatest risk from the effects of pesticides.
The developing brain and nervous system are vulnerable targets: the cells of the nervous system don’t quickly repair themselves after damage, and the blood-brain barrier that protects the brain from toxins is not fully developed until six months of age.
Animal studies also suggest that low-dose exposure to some neurotoxic insecticides (for example, the pyrethroid allethrin) during a brain growth spurt can lead to a greater chance of neurological damage with exposure later in life.
Testing: taking children into account
These findings suggest that pesticides present a greater risk to unborn children, newborns, and children than to adults.
The PMRA is taking children’s vulnerability into account as it re-evaluates its lawn-care pesticides. This has already led to phase-outs of all home-use products for two pesticides: chlorpyrifos and diazinon.
