AFP/Getty Images

Colombia may soon stop using one of Uncle Sam’s favorite anti-drug weapons after recent studies found it could cause serious collateral damage.

This week, Colombian health officials recommended the armed forces immediately halt the spraying of glyphosate — a herbicide that is part of U.S.-backed efforts to eradicate crops of coca, the plant used to make cocaine.


In a letter to Colombia’s anti-drugs police, Health Minister Alejandro Gaviria noted that a recent report by the World Health Organization has found that glyphosate is probably a carcinogenic. Gaviria said spraying coca fields with the herbicide poses a serious health risk to people living near those areas, and as a result is unconstitutional.

Colombia’s president will now have to decide whether to follow his minister’s recommendations.

The use of the herbicide in Colombia’s drug war has been highly promoted by the United States; the U.S. government pays military contractors millions of dollars to operate fumigation flights in the South American country.


Coca is grown in areas of Colombia where impoverished peasants have limited ways to make a living [AFP/Getty Images]

The health minister’s report was quickly rejected by Colombia’s defense minister, who argues that aerial fumigation is an important tool for the military to combat cocaine production in remote areas that are too risky for security forces to enter on foot.

Colombian guerrilla groups, including the FARC, are known to finance themselves through the drug trade, so cutting the coca crop is also a way for the Colombian military to strike at the rebels’ treasure.


A top U.S. State Department official has come out in defense of fumigation campaigns after the health minister’s announcement.

“Glyphosate is probably the most common herbicide in the world. It’s been used in more countries and farms than any other herbicide,” William Brownfield, U.S. assistant secretary for counter-narcotics, told Caracol Radio.

“Colombia is a sovereign country and it must do what reflects its national interest, but they should take a serious look at the scientific evidence. There is not one single example of a person who has suffered damages from glyphosate in Colombia in the past 20 or 21 years,” Brownfield said in Spanish.


A Colombian soldier advances on a coca field, while a spray plane flies overhead. [AFP/Getty Images]

Detractors of the chemical acknowledge that evidence linking glyphosate to cancer is rare. But they argue that spraying coca fields with glyphosate only fuels resentment against the Colombian government in areas where guerrilla groups are influential.

In controlled conditions, glyphosate is sprayed manually on crops or dumped from crop dusters that fly just a few dozen feet above fields.


But in the conditions of Colombia’s drug war, the spray planes have to maintain a higher altitude to avoid being shot down by traffickers or rebel groups.

That increases the risk that fumigation efforts miss their marks and indiscriminately destroy legitimate food crops, angering local farmers and fueling rebel propaganda campaigns.

Adam Isacson, a Colombia analyst at the Washington Office on Latin America, said removing glyphosate from the equation would have “little impact” on drug interdiction.


Isacson said aerial fumigation has been an important component of the U.S. military aid package known as Plan Colombia, but pointed out that U.N. statistics show it has not put a major dent on coca production.

According to a 2013 U.N. report on coca cultivation in Colombia, farmers have adapted to fumigation by interspersing coca with legitimate crops, increasing the amount of fields so that not all of their crop will be exposed and applying substances on coca leaves that make them resistant to glyphosate.


“The fumigation program ran into big trouble in the mid-00s when growers adjusted to the spraying, and by 2007, despite record spraying, coca cultivation rose back to pre-Plan Colombia levels,”  Isacson told Fusion in an email. “Reductions in coca-growing didn’t resume until after manual eradication got going in 2006. Fumigation alone doesn’t work, you need a government presence on the ground in coca-growing areas, not just flying overhead.”

Opponents of glyphosate argue that instead of spraying coca fields, the Colombian government should invest in roads and development programs that enable peasants to make a living from producing legal crops.


Isacson said that last year the Colombian government and the Revolutionary Armed Forces of Colombia agreed to suspend aerial spraying if they sign a peace deal. Both sides also said they would seek voluntary eradication agreements with coca-growing communities.

Manuel Rueda is a correspondent for Fusion, covering Mexico and South America. He travels from donkey festivals, to salsa clubs to steamy places with cartel activity.