Arsenic is the ultimate tasteless and odorless killer. When you consider its relationship to wine, haunting, decades-old headlines like “POISON WINE FELLS 11; French Woman Said to Have Put Arsenic in Vats” (1955) and “300 French Sailors Poisoned By Arsenic in Wine Rations” (1932) may creep to mind.
But the poison’s relationship to vines and agriculture is far cozier than you might realize.
“[Arsenic] was the most common form of pesticide until [World War II], but it was still used in the 1970s and the 1980s,” says Dr. Carolyn Cobbold, Ph.D., research fellow at Cambridge University and author of A Rainbow Palate. “Because of the toxicity of arsenic, it has been used as a pesticide, fungicide and herbicide for a long time.”
Before it found its way into the vineyard, arsenic had a history similar to many other naturally occurring elements now known to be lethal, including lead. It was used as medicine to treat skin and lung diseases across ancient civilizations, and in skin-lightening cosmetics in Victorian England.
“It’s really important to note that arsenic tends to be found throughout the world with other metal deposits,” says Cobbold. “So where you find gold, silver, copper and lead, there’s often arsenic.”
Arsenic: The Total Package?
Arsenic’s prominence as a treatment in American vineyards, orchards and cotton fields began sometime in the late 19th century. Controlling mold and pests in vineyards was a tricky task and many American growers looked to the chemical treatments that had been used effectively in Europe.
“In most vineyard scenarios, the biggest issue is molds,” says Andrew Waterhouse, Ph.D., wine chemist and professor of enology at University of California, Davis. “So gray mold or powdery mildew or downy mildew—those are the big three that have been scourges in viticulture for hundreds of years. So, if they were using arsenic in a vineyard, it was probably because it was effective against some of these molds. [Arsenic] is basically toxic to everything.”
These treatments included organic and inorganic arsenic compounds like monosodium methanearsonate, calcium arsenate, lead arsenate and copper arsenate. They were often commercialized with catchy names like Paris Green.
“If you look back on where it started, you get stories that you can’t necessarily source, but tales like some French farmer spilled Paris Green, which is copper arsenate, on a field and noticed it killed the insects and thought, ‘Aha! Insecticide,’ ” says Cobbold.
An inorganic compound, Paris Green’s bright hue was a product of the blend of arsenic, copper and lime oxide. This particularly deadly combination, also known as copper acetoarsenite, was used to rid vineyards of molds, as well as preserve bodies for burial, create vibrant hues in paintings and wallpapers and even kill Parisian sewer rats—a true all-in-one product.
But whatever form arsenic took, there was little understanding of the lasting effects these chemicals could have on the land or to the people who used them.
“Because [arsenic] was often applied near the barn, they would dump the leftover pesticide when they were done,” says Waterhouse. “So there was usually a hotspot where they would dump the little bit leftover every time they would spray.”
Cobbold adds that arsenic contamination in soil is “pretty widespread worldwide,” and it’s likely that arsenates are still used in places where there isn’t as much agricultural oversight.