Landmark Research Project Connects Pesticides with Increased Risk for Autism, Other Developmental Problems in Children

By Nathan Falde

As measured among eight year olds, the rates of autism spectrum disorder (ASD) in the United States  increased by approximately 220 percent between 2000 and 2010. This means about 1.5 percent of American kids will have been diagnosed with this condition by their eighth birthday (2.4 percent of boys and .5 percent of girls).

This rise is alarming, to say the least. But it becomes even more distressing when we discover that since 1975 occurrences of autism have gone supernova, rising from one in 5,000 kids to one in 68 today. That represents a 73-fold increase for those keeping track at home. Some of this burst is certainly based on changing diagnostic techniques (ASD was not well understood back then), but even as standards for diagnosis have normalized rates have still continued to climb. 

And we must remember that this one-in-68 figure is based on measurements of children born in 2002. Three, four and five-year olds are being diagnosed with ASD right and left and everywhere in between these days, and when future numbers are crunched further explosive growth in the occurrence of this condition will undoubtedly be revealed. In fact, one MIT scientist states that if autism rates sustain their present rate of growth by the year 2025 half of all American kids will have it.

And the problem is not just autism. According to the Centers for Disease Control and Prevention, one in six children in the U.S. now suffers from some sort of developmental delay. So the sudden and swift outbreak of ASD only tells part of the story.

Few scientists looking into the causes of this mysterious phenomenon doubt it is being driven by environmental factors. The only question is which ones, and recent research has identified some likely culprits. Specifically, four classes of pesticides frequently used in commercial agriculture operations.

Are Toxic Clouds Floating Over California? Scientists Seek Answers

Pesticides are potent poisons that kill bugs dead. But most are neurotoxins and if exposure levels rise above a certain threshold they can have toxic effects on human beings and animals as well.

But what exactly represents a safe exposure level for people and animals, anyway? Many have long suspected there is no such thing, since even small amounts of toxins introduced into the human organism can accumulate over time and interact in unpredictable ways with any other poisons that might be present.

Commercial applications of pesticides and herbicides are not supposed to pose much of a risk to human beings, according to the U.S. Food and Drug Administration (FDA)—a thoroughly independent organization with absolutely no ties to the industries it regulates, and anyone who suggests otherwise should be ashamed of themselves. Even though the FDA’s current commissioner, Michael R. Taylor, used to work for Monsanto, he is completely objective now and only concerned with protecting the public interest. Yeah, right!

But despite the tireless efforts of the FDA to protect our health, a 2014 study carried out at the University of California-Davis found a clear link between autism, developmental delays and residential proximity to fields coated with commonly-used categories of pesticides, such as organophosphates, pyrethroids, chlorpyrifos and carbamates. You may not be familiar with these chemical names, but unless you’ve eaten organic your whole life you’ve probably consumed tons of fruits, vegetables and soy or grain products tainted with their residues.

In their hunt for correlations between pesticide exposure and increased risk for autism and developmental delays in children, the Cal-Davis researchers relied on two sources of information: the California Pesticide Use Report, covering the years 1997-2008, and an ongoing California-based health study called CHARGE, which stands for “Childhood Autism Risks from Genetics and the Environment.” The data obtained from each source were cross-correlated geographically, to find out how close pregnant mothers who gave birth to children with ASD (autism spectrum disorder) or DD (developmental delays) had been living to farms, fields, roadway ditches and other locations where pesticides had been applied in volume. Mothers who lived within 1.25, 1.5 and 1.75 kilometers of these pesticide sources were classified as exposed, and with this information in hand the researchers were able to make measure how risk levels for ASD and DD were affected by gestational exposure to bug-killing toxins.

The Autism-Pesticide Link: By the Numbers

When moms lived inside the danger zones all four categories of pesticide were associated with increased risk for autism. Within a residential distance of 1.25 kilometers incidence of the disorder was 60 percent higher than normal following exposure to organophosphates and chlorpyrifos, and approximately 35 percent higher when the villains were pyrethroids or carbamates. In general, reduced proximity to pesticide sprayings meant decreased elevation of risk, which would be expected if the effect being measured were real. Only chlorpyrifos failed to lose any of its apparent toxic potency with distance, remaining linked to a 60 plus percent increased risk even at 1.75 kilometers.

Organophosphate exposure wasn’t connected to greater chances for developmental delays. But chlorpyrifos and pyrethroids both increased DD risk by 50 to 60 percent, and carbamate exposure boosted the likelihood of developmental delays by a jaw-dropping 248 percent. Once again reduced proximity to a pesticide source meant a lesser effect, but again chlorpyrifos were the one exception to this rule.

These statistics are startling and hard to dismiss—although pesticide industry reps and their paid minions will try, launching vicious attacks against the research and against the integrity of those responsible for it (if you want to see this dynamic in action check out the comments sections in any Internet article that talks about the toxic effects of pesticides). They will try to exploit the fact that even the best-designed epidemiological studies don’t really “prove” a cause-and-effect connection in the conventional scientific sense. Controlled studies would be needed for that, but intentionally exposing human beings to poisons to laboratory settings to ascertain their effects would be the epitome of evil and no such experiments will ever be performed, as chemical industry defenders know all too well.

And in truth the developmental pathways of many medical disorders are so subtle and complex that simplistic cause-and-effect relationships likely don’t exist. Epidemiological studies are pretty much all we have in these cases, and to condemn them for what they aren’t is to completely overlook what they are, which is a highly valuable source of non-abstract, real-world information.

They’re Blinding Us (among other things) with Science

Humans are powerfully and inextricably intertwined with the environments we inhabit. Modern agriculture has been drenching the land in chemicals for decades, indirectly sheep-dipping all of us in a witches’ brew of noxious poisons that constantly interact with the cells in our bodies in numerous unpredictable ways. Chemical crap pollutes our air, our water, our food, our soil and ultimately our bodies; we’re swimming in a sea of it on a daily basis and so are our children, including the unborn ones.

False reassurances of big agriculture and big government aside, dumping billions of tons of poisons in areas adjacent to densely-populated regions represents a massive science experiment run amok. It may take a thousand years of experience and study before we know for sure just what all of this exposure to chemicals is doing to us. If no level of exposure is safe, families touched by autism and developmental disorder may, sadly, be the canaries in the coal mining warning us all about what is to come.

In the meantime going organic is one of the few defenses we have to protect ourselves against the predations of the chemical warriors that can and do kill living cells indiscriminately. Growing the market for organic food means shrinking the market for pesticides and herbicides, it is literally a one-to-one relationship. And when we consume organic foods we don’t have to worry about ingesting the chemical residues that contaminate our food supply up and down the line. Organic means cleaner external and interior environments; and the latter depends on the former to a far greater extent than most of us realize.


A little about the author:

unknown-1Nathan Falde and his family live in Bogota, Colombia—where his wife is from. He is the senior medical writer for Sarah's company Coquí Content Marketing. He has been writing professionally since 2010. Although most of what Nathan does is ghostwriting, he regularly contributes articles about addiction to Elements Behavioral Health and their family of websites. Nathan loves to write about science, health and the environment.