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Health and Environmental Effects of Herbicide Spray Campaigns in Colombia

Jim Oldham and Rachel Massey 1
March 18, 2002


Page 1
Page 2
The Human Impacts of the Aerial Eradication Program
Reports from the ground: Human health effects
Page 3
Reports from the ground: destruction of food crops and harm to livestock and farmed fish
Plausibility of Complaints
Page 4
Page 5
Expected ecological effects of herbicide spray campaigns in Colombia
Biodiversity and ecosystem complexity
Page 6
Habitat destruction
Direct effects on wildlife
Page 7
Critiques of the Spray Campaigns


In February 2002, a three-year peace process in Colombia came to an end with President Andrés Pastrana's decision to retake the demilitarized zone ceded to rebel forces in 1998 as a safe haven for peace talks. 2 With this decision, Colombia appears to have returned to full-scale civil war, continuing a decades-long cycle of violence. Ostensibly with the purpose of supporting the "war on drugs," both the Clinton and the Bush administrations have provided substantial military aid to Colombia. 3 The majority of U.S. aid to Colombia consists of assistance to the Colombian military and police forces. These forces are closely tied to paramilitary organizations responsible for the most serious human rights violations in Colombia's vicious civil war. 4 Recently, the Bush administration expanded the possible scope of U.S. military aid to Colombia, requesting Congressional approval for $98 million in military aid to protect an oil pipeline. Some lawmakers advocate providing US military equipment for counterinsurgency operations as well. 5

The pretext for U.S. military aid to Colombia remains the effort to halt the drug trade. In this context, a key element of the aid is support for aerial spraying of herbicides in regions where drug crops are produced. Under U.S. sponsorship, large areas of the Colombian countryside are being sprayed by plane with herbicides. Supporters say these campaigns eradicate coca plants and opium poppies, the raw materials for cocaine and heroin respectively, and will thereby reduce production of these drugs.

According to the U.S. State Department, "the spray mixture [used] against coca throughout Colombia...contains three components: water, a commercially available formulation of the herbicide glyphosate, and the surfactant cosmo-flux 411f." 6 While the U.S. government has refused to name the brand name of the glyphosate herbicide, 7 it has been widely reported to be Roundup Ultra, an herbicide made by the agrochemical company Monsanto. 8 These reports have been confirmed by the Narcotics Division of the Colombian National Police in information provided to the Colombian People's Ombudsman. 9 The composition of Roundup Ultra (41% glyphosate, 14.5% surfactant, and 44.5% water 10) also corresponds exactly to a description of the unnamed herbicide provided by the U.S. Embassy in Bogotá. 11

According to the U.S. State Department, the aerial eradication program is directed primarily against large coca producers. 12 But news stories from The New York Times, The Washington Post, the St. Petersburg Times, the BBC, and other sources make it clear that small land owners, peasant farmers, and indigenous communities have been directly affected by the spray campaigns. Some of these individuals and communities grow coca or opium poppy alongside other crops; many do not grow any drug crops. 13

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1 The authors are, respectively, Amazon Projects Director and Research Fellow at the Institute for Science and Interdisciplinary Studies (Prescott House, 893 West Street, Amherst, MA 01002;;

2 Juan Forero, "Colombia Attacks Rebel Zone as Leader's Patience Snaps," New York Times (February 22, 2002).

3 For details on U.S. aid to Colombia, see Center for International Policy,

4 Human Rights Watch, "The 'Sixth Division': Military-paramilitary Ties and U.S. Policy in Colombia," (September 2001). Available at (visited November 26, 2001).

5 Juan Forero, "Colombia Attacks Rebel Zone as Leader's Patience Snaps," New York Times (February 22, 2002).

6 U.S. State Department, written answer to questions from U.S. Representative James McGovern (D, MA), (March 14, 2002).

7 Deposition of Rand Beers, Assistant Secretary of State for International Narcotics and Law Enforcement Affairs (February 27, 2002). United States District Court for the District of Colombia, Case No. 1:01CV01908, Venacio Aguasanta Arias et al. vs. Dyncorp et al., pp. 42-3.

8 Hugh O'Shaughnessy, "How global battle against drugs risks backfiring," Observer (June 17, 2001); "Guerra contra los cocales," BBC World Service, (visited Nov. 7, 2001); Paul de la Garza, "Roundup Works -- But Too Well?" St. Petersburg Times, (Mon., Aug 6 2001).

9 Eduardo Cifuentes Muñoz, Colombian Human Rights Ombudsman, "Responses to questions from the Colombian Congress" (July 2001).

10 Material Safety Data Sheet for Roundup Ultra, available at

11 Information provided by William Duncan of the Anti-Narcotics Section of the U.S. Embassy, to Lisa Haugaard of Latin America Working Group (February 20, 2002). Dr. Anna Cederstav (pers. comm.) of the Interamerican Association for Environmental Defense reports that recent information from the EPA's Office of Prevention, Pesticides, and Toxic Substances points to the use of a different glyphosate herbicide, Roundup SL, considerably more toxic than Roundup Ultra. This requires further clarification from the government.

12 Bureau for International Narcotics and Law Enforcement Affairs, U.S. Department of State, "Fact Sheet: Eradication of Illicit Crops: Frequently Asked Questions," November 30, 2001.

13 See, for example: Judy Mann, "Waging Chemical Warfare in Colombia," Washington Post (March 16, 2001), p. C11; Jared Kotler, "Colombian Candidate Questions Plan," Associated Press (Sunday August 26, 2001), available at; Juan Forero, "No Crops Spared in Colombia's Coca War," New York Times (January 31, 2001); Paul de la Garza, Op. Cit.

(c) 2002 James Oldham and Rachel Massey
ISIS occasional papers are the work of individual authors and represent their own efforts. Opinions, analysis, interpretations, conclusions, and recommendations are those of the authors and not those of ISIS, its officers, staff, Fellows, or members.