Roundup on Roundup

Scientific studies link the herbicide to cancer, liver disease, and other ailments.

This is first in a two-part series. Next week I will look at the environmental consequences of using Roundup.

In recent weeks and months, Roundup and Bayer, the multinational pharmaceutical, chemical, and biotechnology company that makes the herbicide through its subsidiary, Monsanto, have received severe legal setbacks. Science is also revealing the health hazards of the most widely used weed killer on the planet.

On Tuesday of this week, a California jury awarded $332 million in damages to a man who sued the company claiming his cancer was caused by Roundup. In two previous lawsuits, the German-base company was ordered to pay individuals $175 million and $1.25 million for damages that Roundup allegedly caused to their health.

Despite these jury awards, the U.S. EPA says that there are no major health risks to humans from glyphosate, the main plant-killing ingredient in Roundup, if the product is used correctly. Industry allies have also come to Bayer’s defense. I have worked with Roundup¹ and have worked with conservationists, restoration ecologists, and gardeners who swear by it and extoll its use because of its safety. Once, while using Roundup to clear weeds in preparation for planting a native plant garden, I saw one fellow take a gulp of Roundup in a show of the substance’s safety to humans.

Kills weeds, not the lawn, but there might be other problems.

If the EPA, as well as a lot of folks who work with it, says it’s safe, what did these juries hear to make them decide that glyphosate caused the cancers of the individuals who sued Bayer?

The science on glyphosate and health

Glyphosate, most commonly known as Roundup, the trademarked name under which Monsanto² markets and sells its product, has been around for almost 50 years and is the most widely used herbicide in the United States.

The International Agency for Research on Cancer (IARC), part of the World Health Organization, issued a report in March of 2015 classifying glyphosate as a probable carcinogen to humans. The IARC made this conclusion after reviewing around 1000 studies. Some of the studies looked at people who were exposed to the herbicide through their work. Other studies were performed in controlled labs.

Industry and friendly publications have criticized the IARC’s work. National Review characterizes the work of the United Nations-based organization as “misrepresenting data, editing drafts to delete contrary evidence, and using the report as propaganda to promote their own anti-glyphosate agenda.” I am not trying to be an apologist for either side of this debate, but some of the studies upon which the IARC relied experimented on animals using “pure” glyphosate, a concentration that is nearly impossible in the real world.

Other recent science

In recent decades, rural Sri Lankans have been plagued by a rise in the occurrence of kidney failure; similar outbreaks have affected farming communities in the tropics. In Sri Lanka, up to ten percent of children between the ages of five and eleven show signs of early onset kidney damage.

One of the selling points of glyphosate is that it breaks down quickly, within days or weeks. A research team, however, looked at how the herbicide interacts with the environment of Sri Lanka and found a problem. Many parts of Sri Lanka are arid. Combined with certain geological conditions, this can lead to groundwater being hard. When glyphosate encounters this hard, mineral-rich water, it can form glyphosate-metal ion complexes. Instead of breaking down quickly, the complexes can persist up to seven years in water and 22 years in soil.

The team sampled 200 wells in four regions of Sri Lanka. They found high levels of glyphosate in 44 percent of the wells in the areas with high rates of kidney disease. Only eight percent of the wells outside the affected areas showed evidence of the herbicide. They also found fluoride, also associated with kidney disease, in 99 percent of the wells in affected areas and 80 percent of the other wells. While there are other factors in the prevalence of kidney disease in parts of Sri Lanka, the study indicates that the introduction of glyphosate exacerbates the conditions causing kidney disease and failure.

Charles Limbach, a family physician in the Salinas Valley, had noticed over the past several years that many of his younger patients were showing signs of liver and metabolic disease, a disruption of the body’s ability to process and distribute proteins, fats, and carbohydrates. Limbach surmised that the problem might be from the Roundup used in the agricultural fields in the Salinas Valley.

Dr. Limbach and other researchers collected urine samples from children ages 5, 14, and 18 in the Salinas Valley. When glyphosate degrades, one byproduct is aminomethylphosphonic acid. Children who had elevated levels of this acid in their urine had a 14 percent higher rate of liver transaminases, an elevation of certain enzymes that can lead to severe health complications. and a 55 percent increased risk of metabolic syndrome in early adulthood.

Research out of the University of California San Diego

In a study from the Department of Family Medicine and Public Health at UC San Diego School of Medicine, researchers measured glyphosate levels in two groups of patients, those with nonalcoholic fatty liver disease and those with no sign of the disease. They found across the board—across differences of age, race, body mass index, ethnicity, or diabetes status—the patients with liver disease had significantly higher levels of glyphosate in their urine.

Another group at the UC San Diego School of Medicine assessed five neurobehavioral performances: attention and inhibitory control, memory and learning, language, visuospatial processing, and social perception from hundreds of children, ages 11 through 17, in an agricultural area of Ecuador. They also measured for the presence of the insect repellant DEET, glyphosate, and another herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D). Children with high levels of 2,4-D had problems with several of the behavioral performances. Children with high levels of glyphosate suffered decreased social perception, the ability to make proper inferences of others and understand social cues.

What you can do

To avoid herbicides and pesticides rinse your fruit and vegetables before you eat them. If you’re really concerned about your exposure to pesticides, you can rinse your fruits and vegetables with water mixed with a little baking soda. You will do even better by buying organic produce or produce from regenerative farms, which do not use of glyphosate or other harmful herbicides. Best of all, grow your own garden—no pesticides or herbicides and a lot of fun.

1. In Southern California, it is often used to kill some of the most hard to kill invasive weeds. Clearing the invasive giant reed (Arundo donax) is almost impossible without Roundup.

2. In June of 2018 Monsanto was acquired by Bayer.