The Neurotoxicity of Pesticides

The Neurotoxicity of Pesticides

Insecticides, fungicides, and herbicides. Oh my! 


These, along with rodenticides (used to control rodents), acaricides (used for mite control), and molluscides (to control snails and mollusks) are all classes of pesticides that have far reaching effects. Within each class of pesticide, are different subclasses with various chemical and toxicological characteristics.

Pesticides, substances used to control unwanted pests, insects, and weeds, are one of the largest groups of toxic chemicals produced, stored, and used in the world. Not only are they designed to control pests through their various mechanisms of action, but they have also proven toxic to non-target organisms - namely humans and beloved pets.

If a chemical is designed to poison or destroy the nervous system of a pest, it can certainly have the same effect, or worse, on people.

We would never drink from a container labeled “poison”, yet if we eat food sprayed with toxic and poisonous chemicals, that is exactly what we’re doing. The effects may not be immediate, but the slow accumulation of these toxins can be devastating.

Devastating effects of pesticides

Several pesticides have been identified as developmental neurotoxins. They interfere with chemical neurotransmitter function, cause neurotoxic effects, and can ultimately be fatal. Let’s take a closer look at a few of these.

One class of herbicides, the chloroacetanilides, has proven neurotoxic in laboratory animals and fetuses. It is toxic to fish and carcinogenic, yet its residues are commonly found in groundwater supplies. Exposure can lead to organ dysfunction and central nervous system symptoms. Even though small amounts can prove poisonous, these herbicides are widely used.

Bipyridyl, used in pesticides, is linked to skin cancer on those who manufacture it. For the rest of us, exposure may damage dopaminergic neurons, which may lead to the development of Parkinson’s. Exposure also causes physiological changes to take place within the body and brain, which may lead to neurotoxicity. Despite these risks, the full impacts of bipyridyl on public health is unknown.

Triazines, one of the largest group of herbicides, recently underwent a cumulative risk assessment by the EPA. It was determined that exposure to triazines can cause neuroendocrine and endocrine-related developmental, reproductive and carcinogenic effects, commonly manifesting as ovarian cancer. Despite this, triazines are being praised for having “a low oral toxicity” and for being “unlikely to pose acute hazards with normal use.” The EPA also claims they “do not produce developmental toxicity, with the exception of ametryn, metribuzin, atrazine and cyanazine, which may be slightly to moderately hazardous.” 

And what about the worst offender - the organophosphates? It is estimated that there are about 45 different organophosphate pesticides available on the market, and most have the potential to damage the nervous system.

One of them, an insecticide called chlorpyrifos can harm the developing brains of children who eat food that has been treated with it. Children exposed to organophosphates often have mental and psychomotor developmental delays. Those who have been exposed to high amounts are likely to exhibit signs of ADHD, have an increased risk of autism, and may develop tremors. In fact, the higher the level of organophosphates found in children, the lower their working memory and IQ.

Toxic chemicals are silently damaging our children’s brains.
— Kelly

Not surprisingly, children are more sensitive to the effects of these chemicals because their young bodies lack the enzymes responsible for deactivating the toxins.

It’s also no secret that organophosphates are poisonous. They kill insects the same way that sarin gas kills people - by causing nerves to fire uncontrollably. Like asbestos, however, they are still legally used in the United States, with the notion that exposure to small amounts is safe. The saying “the dose makes the poison” sums it up for me. 

Yes, it is true that pesticides are “more regulated” than other industrial chemicals. They must meet federal standards to protect the health of humans and the environment before the EPA will grant a license that allows its sale and usage. However, not everyone believes the EPA’s limits are suitable for everyone.

Take chlorpyrifos, marketed by Dow Chemical, for example. Since the 1960’s it was the most commonly used insect killer in the US. But due to hundreds of poisoning complaints, Dow removed it from household products in the year 2000. Despite this small step in the right direction, it is still commonly used in plant nurseries and greenhouses, and sprayed on golf courses and wood products. Chlorpyrifos is currently classified as “very highly toxic” to birds and fish, and “moderately toxic” to mammals. Why its use is still being allowed is beyond me!

What can we do about our toxic world?

With all these toxins and chemicals being sprayed into the air we breathe and on the foods we eat, you may think it’s a lost cause. But please think again.

In a perfect world, we should all know, and care, about how our food is raised, handled, and cultivated. This extends to the care and treatment of animals, employees, and the earth, as well as the cleanliness of the food we eat.

To avoid as many of these harmful pesticides as possible, your best bet is to choose organic. As I discussed last week, this is especially important if the fruits and vegetables you buy have thin, soft skins, as these tend to absorb more toxins. Even if washed extremely well or peeled, many toxins sprayed on the fruit are still present within its flesh.

It also bears noting that some toxic chemicals banned from use in Canada may still be legal and sprayed on foods in other countries then imported for sale here - another good reason to choose organic and know where your food comes from. 

Choosing organic is only one way to ensure your food has little to no pesticide residue, but other options also exist. We can consider growing our own food, buying local, getting to know your farmer, and gathering non-cultivated food that exists all around us.

Any of these options will help shape the future of our food system and support the local economy. Not only will this benefit the consumer interested in better health, but will be good for the environment, the land, birds, bees, animals, and helpful critters that live on or near farms. Ultimately, this will create a greater shift towards a healthier earth - and in turn, a healthier population.

To me, all toxins are undesirable, even in minute amounts. Some are carcinogenic while others damage brain cells, affect cognitive function, induce disease, and hinder growth in children. It is especially important that we keep our children and unborn babies away from the harmful effects of all toxins. You just never know what dose will tip the scales. It’s simply not worth risking our children’s lives and futures. 

As educated individuals, we are becoming more aware of the negative effects toxins have on our bodies and brains. Thanks to public outcry, regulatory organizations are lowering the “safe” and “allowable” limits of toxins, and we are trying to develop safer alternatives. Unfortunately, the greater concern lies in what we’re exposed to and don’t yet know to be toxic.

This is the main reason I choose to know where my food comes from and support my local farmers. I encourage you to do the same. Become an advocate for our food supply and support local farmers and the local economy. In the end, the Earth will thank you for it.

As always, I value your opinion. Please let me know what you think in the comments below.

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