Are Pesticides Harming Children’s IQ and Behavior?
16 Aug, 2011
By Alice Shabecoff
Pesticides can harm your child as much as they hurt insects, leading environmental scientists have discovered. Children exposed either in the womb or during childhood may end up with lowered IQ scores, or ADHD, or other behavioral and emotional problems.
This milestone finding was just reported in separate studies, published simultaneously, from three leading institutes of environmental health science, from New York to California. The institutes all focused on prenatal exposure to one immensely popular kind of pesticides, called organophosphates. Altogether, they have been following and testing about 1,000 pregnant women and their children over more than a decade. In New York City, the families tracked by Columbia University’s Mailman School of Public Health and Mount Sinai School of Medicine were urban, but, it turned out, they used more of this pesticide inside their apartments to control cockroaches and other pests than all of New York State’s agricultural counties. The School of Public Health at the University of California, Berkeley, focused on farmworker children in the fertile Salinas Valley, our country’s top vegetable-producing region.
Their research found that the higher the mother’s exposure to pesticides, the lower the child’s IQ score once the child reached school age. In the Berkeley study, for example, children with the highest levels of prenatal pesticide exposure tested 7 points lower than children exposed to the least. There was no threshold or base limit of exposure that did not produce an effect. Even by age three, the children showed neurodevelopmental problems. Prenatal exposure was measured by testing the mother’s blood and urine, or by testing the newborn’s umbilical cord blood.
These reports further substantiate a report from Harvard University last year, indicating that organophosphate exposure, at levels common among US children, may contribute to ADHD prevalence.
Once upon a time, it was thought that the placenta served as a barrier protecting the fetus from all harm. Now we know that many toxins cross the placenta in strength; and recent science has also discovered that the embryo and fetus, whose bodily defense mechanisms are undeveloped, are particularly vulnerable.
Yet regulation of pesticides has been based on outdated 1990s’ tests that looked only at how these chemicals affect the body and mind of adults. Additionally, it has been discovered that some people (mother and/or baby) have a genetic variation that leaves them with a lower level of certain protective enzymes. However, regulation remains a “one-size-fits-all” business.
Organophosphate pesticides are chemically similar offspring of the chemical warfare agents Germany developed in its pursuit of nerve gas during World War II. They are chemically similar to the chemicals that Saddam Hussein used to kill thousands of Kurds.
This chemical class works by attacking a neurotransmitter in the insect nervous system, getting the system so overexcited that the insects die. But this same neurotransmitter is found throughout the animal kingdom, including in humans, where a chemical assault can impair the development of the brain’s prefrontal cortex. The effect on the prenatal or newborn human brain can be permanent structural damage.
Thanks to the earlier discovery by the three environmental health centers of this danger, the EPA convinced Dow, the manufacturer of the most popular organophosphate, Dursban, to withdraw it from household use in 2001. But Dow (though sued many hundreds of times by families of affected children) maintains that the chemical family poses no threat, and it remains the most favored of all commercially used insecticides. US agribusiness, according to latest figures, from 2007, uses 33 million pounds a year of organophosphates, one-third of all the insecticides applied in this country. That explains why traces of organophosphates were found in the urine of 82 percent of Americans sampled by the Centers for Disease Control and Prevention (CDC) a few years ago.
Defending this product against the damaging findings of these three current studies, the agribusiness trade organization CropLife America just put out this statement: “Organophosphate insecticides, along with all crop protection products, are an important part of American agriculture and are vital tools for today’s modern farmers. The safety of consumers and growers alike is protected every step of the way, from initial product development to final use.” Indeed, conventional agribusiness depends on the vast use of pesticides along with other harmful tools such as the vast use of antibiotics.
Although the greatest damage from exposure to these toxins takes place while the baby is still in the womb, that doesn’t mean exposure after birth is safe. To the contrary, pesticides have been shown to be harmful throughout childhood (and even later in life, including among farmworkers). Exposed children may have difficulties performing tasks that involve short-term memory, and may show impaired mental development or pervasive mental, social and emotional problems that last throughout their lives.
One of the saddest stories of childhood contamination tells of the Ebling family, who, with their small son named A.J. and daughter Christina, moved into a new apartment complex in Indiana that had been sprayed repeatedly with Dursban mixed with another pesticide. Both were healthy, normal children when the family moved in; soon they were convulsed by seizures, and today the now-teenage daughter drools, slaps and bites, and has the capacity of a three-year-old, while the boy has an IQ of 44. They are one of the families suing Dow.
The story of organophosphates is really the story of all pesticides. The equivalent of the American Academy of Pediatrics in Ontario, Canada, concludes that there are no pesticides less dangerous than others; they just have different effects on health that take different periods to show up.
Parents can reduce their child’s exposure to pesticides, though it certainly involves efforts on many fronts. In homes with pest problems, sealing up any openings in baseboards and getting rid of food residue does the job and is more effective and less costly than pesticides in controlling cockroaches. Lawns, frequently doused with pesticides and other powerful toxins, can be green with natural care.
Sadly, schools are often the scene of surprisingly heavy doses of pesticides, routinely sprayed in school kitchens, cafeterias, athletic fields, playgrounds and classrooms, many times without notifying parents in advance. But a strong parent movement is incrementally bringing about change.
Above all, what you and your child eat is critical. Nutritious food actually builds a body’s defenses against harm; it can actually turn on genes that prevent diseases. Nutritious is not, however, the norm to many American families. Most conventional diets of fruits, vegetables and juices, and most wheat- or corn-based foods such as pasta, cereal or chips have been found to be both stripped of their nutrients, and, on top of that, routinely doused with organophosphates, weedkillers and other chemicals.
Healthful eating should begin when a couple is trying to conceive or, even better, at least a year before that. Dr. Alex Lu of Harvard University’s School of Public Health explains that preliminary data from animal studies show that the mother’s toxic exposure may cause genetic changes which may lie hidden until they express themselves in her child. So he concludes that the diet of women of childbearing age is of prime importance.
Nutritious, chemical-free food remains critical through pregnancy and breast-feeding, and as the child grows up. If, however, a family has come late in seeing the value of chemical-free food, late is better than never.
A study from Dr. Lu in collaboration with researchers at the University of Washington found that an organic diet, when it is launched, can clear pesticides from a child’s body. Of course early exposure may have triggered some harm; but damage is cumulative, so halting the exposure as soon as possible minimizes the toxic burden and offers “dramatic and immediate protective effects,” the researchers conclude.
The three just-released studies were all published in the journal Environmental Health Perspectives and are available online, http://ehp03.niehs.nih.gov.
The report from Harvard researchers was published in 2010 in the journal Pediatrics, under the title “Attention-Deficit/Hyperactivity Disorder and Urinary Metabolites of Organophosphate Pesticides,” Maryse F. Bouchard, David C. Bellinger, Robert O. Wright, and Marc G. Weisskopf, http://pediatrics.aappublications.org.
Resources for further information and help:
Beyond Pesticides, Inc., www.beyondpesticides.org, offers these practical information resources:
—a database of harmful effects of the 48 pesticides most commonly used in schools, www.beyondpesticides.org/schools/publications/48 School Pesticides.pdf;
—a database of harmful health effects of the 30 commonly used lawn pesticides, www.beyondpesticides.org/lawn/factsheets/30health.pdf;
—a chemical-by-chemical database on pesticide hazards, www.beyondpesticides.org/gateway/index.htm;
—a continually updated, searchable Pesticide-Induced Diseases Database, with citations to hundreds of scientific studies that link health effects to pesticides, www.beyondpesticides.org/health/index.htm;
—a national directory of less toxic pest control companies, www.beyondpesticides.org/safetysource.
Environmental Working Group publishes a Shopper’s Guide to Pesticides in Produce, listing the 12 most contaminated and 15 cleanest fruits and vegetables, www.ewg.org/foodnews/.
Environment and Human Health, Inc., publishes the booklet Risks from Lawn Care Pesticides, with advice about alternative green care, www.ehhi.org/reports/lcpesticides.
The Northwest Coalition for Alternatives to Pesticides, www.pesticide.org, offers
—online fact sheets about pesticides, www.pesticide.org/get-the-facts/pesticide-factsheets;
—information about the harmful use of pesticides in schools, www.pesticide.org/Our Work/healthy-schools-healthy-kids.
Pesticide Action Network, www.pesticideinfo.org, offers
—a chemical-by-chemical searchable database covering toxicity and regulatory news, www.pesticideinfo.org/List_ChemicalsAlpha.jsp;
—a searchable database tracking pesticides on meats, fruits and vegetables, and also pesticides that harm bees, www.whatsonmyfood.org.
More information on pesticide residues can be found at www.whatsonmyfood.org.