Purity, Pestilence, and Pesticides

Pesticides kill unwanted plants and insects, but are they hurting us too?

A good lawn is curated, engineered, and sterile. They’re patches of green without the need for the unruly abundance of nature, and their purity and discipline hinge on one thing: pesticides.

Herbicides, insecticides and fungicides are diverse in their methods and targets, but all are designed to kill. They’re synthesized in labs to disrupt essential biological processes, dismantle cell membranes, paralyze nervous systems, erode exoskeletons, and clog up breathing holes. They emerged alongside modern chemicals of war, often with the same underlying chemistry and always with the same intent: eradicating anything deemed foreign and unwanted.

In this way, both pesticides and chemical warfare have abetted nationalist ideologies since their conception. Chemical warfare, used against enemies abroad, and pesticides, used against domestic pests on farmland and on the lawn.

Glyphosate is the most prolific of these weedkillers, applied to agricultural fields and lawns at a rate of 280 million pounds annually. It’s non-selective and systemic; when sprayed onto foliage, it quickly absorbs into the bodies of plants and inhibits the enzymes that create amino acids and allow for plant growth. Unwanted plants wither in a matter of weeks, but the weedkiller continues to spread through wind, soil, and runoff water.

“We know that herbicides from crops and farms can end up in the dust of houses miles away, even when those people don’t use those herbicides on their own lawns,” said Dr. Lauren Trepanier, a veterinarian at the University of Wisconsin. “They’re pretty ubiquitous.”

The frequency of use and ease of spread has drastic consequences for life everywhere, but especially the life that rolls around on herbicide-tainted lawns and generally lives closer to the ground: our dogs.

Glyphosate is everywhere, and the ways through which it can enter the canine body and bloodstream are multitudinous. It can be lapped up from contaminated streams, it can stick to fur and then be licked off, it can be dermally absorbed through toe pads or anywhere the skin is broken, it can be simply breathed in through pesticide spray drift or from contaminated dust inside. At low levels, contamination shouldn’t affect a body — enzymes in livers are built to neutralize environmental toxins like glyphosate. But with prolonged and inescapable exposure, the level of blood concentrations rise, and quickly overwhelm a pet with toxicity.

Once inside, glyphosate permeates the entire body. It travels easily between the stomach and the bloodstream, damaging all intestinal linings in its wake. Its ability to mimic the body’s natural phosphate structures allows it to transgress the body’s biological barriers, flowing from bloodstream to brain to bone marrow and back again. This kind of oxidative stress—or the overpowering of the body’s antioxidants by invading free radicals—is an essential precursor to DNA damage and cancer cells.

“If you take dog white blood cells and you expose them to glyphosate or 2,4-D [another kind of pesticide], there is DNA damage, and it’s not at a huge concentration. It’s at a concentration that we estimate is achievable in dog blood,” said Dr. Trepanier, who studies the effects of environmental toxins like pesticides on dog lymphoma and bladder cancer.

If a white blood cell fails to self-repair damaged DNA in its nucleus, it begins to rebel against the order of the body. The cell proliferates, rapidly and uncontrollably, and does not die when it’s supposed to—within weeks or even days, the incessantly growing cell can become a tumor.

Canine lymphoma is a disease without a focal point, and tumors will appear all over the body: in lymph nodes under the jaw, on the shoulders, and behind the knee, and in the liver, spleen, chest and stomach. Apart from the swelling of these lymph nodes, symptoms are similarly vast and varying —dogs may experience coughing, difficulty breathing, vomiting, lethargy, and lack of appetite. Left untreated, it will cause widespread organ and respiratory failure in a matter of weeks. Even if diagnosed, the dog will survive maybe a year on chemotherapy.

In the same vein, bladder cancer begins as a mass of multiplying cells of the bladder lining, then closes over the entrance to the urethra or bladder neck, causing pain and blood in urine before the dog dies of kidney failure or is euthanized. But the issue of contamination does not end with pets.

“Dogs are like canaries in the coal mine for people,” said Dr. Trepanier.

What happens on the smaller timescale of their lifespan could just as well be incubating in the human bodies around them.

The breadth of pesticides and their varying mechanisms leave no part of the body untouched. Organophosphates and carbamates shoot down nerve signals and cause cognitive impairment, tingling and numbness in the limbs, and, with long enough exposure, Parkinson’s. In cases of acute exposure, people may experience dizziness, nausea, vomiting, blurred vision, muscle convulsions, and coma. Organochlorines damage livers and kidneys, disrupt hormones and cause birth defects, miscarriages, seizures, and cancer.

Neonics, one of the most widespread and powerful insecticides, mimic nicotine in the nervous system by binding to nerve receptors. In insects, they cause intense overstimulation and disorientation, followed quickly by paralysis and death. They are the leading cause of the honey bee and pollinator die off, and likely the cause of the massive declines in bird populations. Herds of deer with neonic-associated birth defects have begun cropping up in Montana and South Dakota — entire groups are found with pronounced underbites, enlarged right heart ventricles, deformed spleens and genitals, and general lethargy and early mortality rates. Though claimed by manufacturers not to affect humans, they target the same areas of our brains and invade our placentas as well, and human biomonitoring, the measuring of chemicals in human blood, urine and hair, has found evidence of neonics in the bodies of at least half the US population.

Scientists are always developing new pesticides with more efficient kill rates. In other countries, they must be proven safe before use. But in the U.S., they are only blacklisted when proven unsafe. This disparity is reflected in the EPA’s classification of glyphosates as non-threatening to human health compared to WHO’s classification of “probably carcinogenic to humans.” The Trump administration recently published an executive order to ensure glyphosate supply, citing the threat to food security if banned in agriculture.

Since World War II, pesticides and nationalism have been inextricably linked. Nationalism sought to weed out those who threatened monoculture, and chemicals became the most effective means of accomplishing this. Their growth paralleled each other, and converged with emerging research on chemical warfare like mustard gas and tabun. Countries began stockpiling chemical weaponry for invaders that threatened the country: foreign wartime enemies and agricultural pests alike.

During the Vietnam War, The U.S. sprayed millions of gallons Agent Orange—a precursor to modern glyphosate-based Round Up—over Vietnamese forest and agricultural land in an unprecedented act of ecocide. The prolonged exposure of Vietnamese citizens and veterans causes the chemical to slowly and excruciatingly eat at the nervous system, the brain, the lungs, and other vital systems until the victim eventually succumbs to cancer or general illness. And the chemical plagues future generations as well: birth defects such as spina bifida, malformed hearts and livers, physical and mental disabilities, are found in the children of those exposed.

There is no shortage of tragedy when it comes to lawn chemicals, but perhaps the most terrifying aspect is our unawareness of where they come from and what they do. They are descendants of some of the most sinister creations of modern chemical warfare, indiscriminate in their intrusion and destruction of plants, invertebrates and vertebrates, sequestering in our bodies at rates we don’t yet comprehend. As Dr. Trepanier says, the smaller animals around us are our canaries: the pesticide-induced breakdown of their bodies signals what is likely happening in ours, and what will continue to happen if we fail to heed their warnings.