Study linking organophosphates and ADHD stirs apple growers
News of a new study associating organophosphate pesticides with higher incidence of ADHD (attention deficit/hyperactivity disorder) in children caused a stir in the fruit industry, and apple growers plunged into an e-mail discussion on the Apple Crop/Virtual Orchard network.
The study, published in Pediatrics and conducted by a team of researchers at University of Montreal and Harvard University, found that children with higher-than-median levels of organophosphate metabolites in their urine had 1.93 times the incidence of ADHD as children in which no such metabolites were found.
The team studied 1,139 children, of whom 119 were diagnosed with ADHD.
Apples and apple product were not mentioned in the study, but apple growers responded, perhaps because of the on-going phase-out of azinphos-methyl and questions over the future of phosmet. Or perhaps because they remember Alar in 1989. Within a day, the news appeared in more than 400 print and broadcast stories, including the major television and cable networks.
The study only mentioned malathion and its use on strawberries, blueberries, and celery. There was no listing of the estimated 40 OP pesticides in use today, or their many and varied uses in mosquito abatement programs, household pest control, yard and garden applications, and others.
The study indicated an association, not a cause and effect, and Time magazine noted this in the lead of its story, saying that “studies linking environmental substances to disease are coming fast and furious,” linking chemicals in plastics and common household goods to rising rates of modern ills like heart disease, obesity, diabetes, and autism.
Rates of diagnoses of ADHD rose 3 percent per year in the years from 1997 to 2006, Time said, quoting figures from the Centers for Disease Control and Prevention. Those years of increasing discovery of ADHD coincide with years of declining use of OP pesticides in fruit production. Today, about one child in eight is diagnosed with ADHD.
In the Apple Crop e-mail comments, Rick Weinzierl at the University of Illinois, noted:
“We've been reducing use of OPs (organophosphates) on apples in the U.S. since FQPA (the Food Quality and Protection Act) in 1996. The regulations have been driven by both scientific and emotional concerns that OPs, as residues on foods, present more risks than the EPA (U.S. Environmental Protection Agency) finds acceptable. Let's admit that there has been an underlying concern out there for some time, and it is not all driven by fanatics or anti-pesticide groups.
“After we admit that to ourselves, let's brag on the fact that we have responded to the concerns and the regulations by reducing OP use. Penncap-M (methyl parathion) is no longer used at all; Lorsban (chloropyrifos) is used only in ways that should result in no residues on apples or peaches; Guthion (azinphos-methyl) is not used on peaches and is nearly gone from our spray programs in apples; and Imidan (phosmet) is used far less than it used to be.
“We might be wise to spend only a minimum amount of effort criticizing this particular study and instead tout our progress.
“I realize that successive rounds of investigations will target newer groups of insecticides, and we'll have to face truths and rumors that result from them as well. For now, energy might be best spent on making our progress very evident to the public.”
Con Tras, an Irish apple grower who frequently comments on Apple Crop, noted that ADHD, in others studies, has been associated with food colorants, carbonated drinks, and consumption of sugar. Time mentioned the studies suggesting an association between ADHD and videogaming, hyperkinetically edited TV shows, and flashing images shown to young children.
The reasons for concern, as expressed in the study, are that organophosphate pesticides kill pests by affecting the neurotransmission system, disrupting the cholinergic signaling in the nerve pathway, the same mechanism that is thought to occur in ADHD.
The study did not advocate changing diet or shifting away from eating fresh fruits and vegetables, but it did say diet was the most likely source of OP intake by children.
The dialogue took place on firstname.lastname@example.org.