This is an August 2007 copy of a website maintained by the Center for International Policy. It is posted here for historical purposes. The Center for International Policy no longer maintains this resource.

Last Updated:4/2/03
State Department Fact Sheet: Aerial Eradication of Illicit Crops: Frequently Asked Questions, March 24, 2003
Fact Sheet
Bureau for International Narcotics and Law Enforcement Affairs
Washington, DC
March 24, 2003

Aerial Eradication of Illicit Crops: Frequently Asked Questions

Question: What is the aerial eradication program?

Answer: The aerial eradication program in Colombia is a program of the Antinarcotics Directorate of the Colombian National Police (DIRAN- CNP), supported by the Narcotics Affairs Section (NAS) of the U.S. Embassy in Bogota. This program uses aircraft to spray a glyphosate- based herbicide mixture on fields of coca and opium poppy, which are illegal in Colombia and are the vital ingredients of the cocaine and heroin trades.

Question: How are spray targets selected?

Answer: The Government of Colombia (GOC) chooses the areas to be sprayed through an interagency process. The DIRAN reviews information from a variety of sources and flies over growing regions on a regular basis to search for new coca and opium poppy growth and to generate estimates of the illicit crops. These flights target the areas identified by the Colombian National Police in their estimates of illicit crops. An aircraft-mounted global positioning computer system identifies the precise geographical coordinates where those crops are being grown. A computer program then sets up precise flight lines (the width of a spray swath) within that area.

The DIRAN decides which areas of the country may not be sprayed and notifies the NAS Aviation Office. Spraying is conducted only in those areas that the Government of Colombia has approved. If the DIRAN has approved spraying in a given area, spray pilots then fly down the prescribed flight lines set up by the computer program and spray the crops located there. A light bar mounted on the spray aircraft tells the pilot if he is more than three feet off the flight line. Although the pilots fly along a predetermined flight line, they release the spray only when they have visually identified coca in the flight line.

Question: What is the role of the U.S. Government in the aerial eradication program?

Answer: The Embassy's NAS Aviation Office supports the Government of Colombia's aerial eradication program with technical and scientific advice, herbicide, fuel, spray aircraft, and a limited number of escort helicopters. The NAS Aviation Office coordinates regular reconnaissance flights piloted by a Department of State contractor that also provides maintenance, technical support, and some pilots.

Spray missions are flown by Department of State contractor pilots, both U.S. citizens and third-country nationals, and Colombians.

Question: What type of environmental monitoring and oversight is there?

Answer: Environmental monitoring and oversight is conducted by the Government of Colombia, which contracts an independent Environmental Auditor to the spray program. This individual reviews spray areas with the DIRAN and regularly monitors the results of spraying through field checks and analysis of data from the aircraft-mounted computer system that records the quantity and location of herbicide released from the spray nozzles. The Environmental Auditor conducts field checks and reviews photographs, imagery, and data from the aircraft- mounted computer system to verify the accuracy of the spray missions and to check for possible spray drift or overspray. The Environmental Auditor often accompanies the spray pilots on eradication missions, as does a representative of the Attorney General's office. In addition, an August 2000 revision to the Colombian law governing aerial eradication of illicit crops provided for the creation of an Interinstitutional Technical Committee of Colombian Government officials, which has an oversight/advisory function with respect to aerial eradication. This committee, which is headed by the National Directorate of Dangerous Drugs (DNE) and includes representatives from the DIRAN, Colombia's Alternative Development Agency (PNDA), and local and national environmental agencies, is charged with reviewing and analyzing information on the effects of aerial eradication on human health and the environment, and making recommendations on areas to be sprayed.

Question: What chemicals are being used in Colombia for the eradication of illicit crops?

Answer: The only herbicide used for aerial eradication is a formulation of glyphosate, the most widely used agricultural chemical in the world. It is commercially available under many different brands in Colombia and worldwide. The aerial eradication program uses less than 13% of the total amount of glyphosate used in Colombia each year. The majority of the glyphosate used in Colombia is used by local farmers weed control in crop fields before seeding rice, cotton, corn, sorghum, barley, and soybeans; for weed control in plantations of coffee, fruit trees, plantains, bananas, and African palm; as a maturing agent in the production of sugar cane; and even by growers of coca and opium poppy to control weeds.

Besides water, the only other product added to the commercial formulation of glyphosate is Cosmo-Flux 411f, a Colombian- manufactured surfactant. A surfactant facilitates the dilution of oily substances in water and therefore helps the glyphosate mixture to penetrate the waxy outer layer of the coca leaf. Many common household products, such as shampoo and dishwashing detergents, contain surfactants. A detergent is by definition a surfactant. In mixing these products together, the spray program follows the same practices as many legal agricultural users in Colombia and elsewhere. Cosmo-flux is registered and sold commercially in Colombia. In addition, the EPA has reviewed its ingredients and determined that they are the same as those in one or more pesticide products or formulations registered by the EPA for use in the U.S. These individual chemical compounds are also exempted from tolerances of residues on or in human food and livestock feed crops (40 CFR 180.1001) and cleared by the FDA for use in foods (21 CFR).

Question: Has glyphosate been tested for environmental safety?

Answer: Yes. Glyphosate has been extensively tested and evaluated in Colombia, in the United States, and in other countries around the globe. Worldwide, it is among the most widely used herbicides by volume and is currently employed in over 100 countries for a variety of agricultural purposes. Since 1974, after repeated, thorough reviews of numerous required scientific studies on human health and the environment, EPA has licensed glyphosate and many of its commercial formulations for a broad range of agricultural, industrial/forestry, and residential uses in the U.S. EPA estimates current annual use in the United States to be 74 million pounds of glyphosate for agricultural purposes and another 16-22 million pounds for non-agricultural use.

Question: Does glyphosate harm cattle, chickens, or other farm animals?

Answer: At the concentration used in the spray mixture and the methods used to apply it, glyphosate is highly unlikely to harm farm animals, even if an animal were directly exposed to the spray. Glyphosate is poorly absorbed from the digestive tract and is largely excreted unchanged by mammals. When received orally or through the skin, it has a very low acute toxicity. In long-term feeding studies of cows, chickens, and pigs, levels of glyphosate were undetectable in muscle tissue, fat, milk, and eggs. See Malik, J., G. Barry and G. Kishore, "Minireview: The Herbicide Glyphosate," Bio Factors 2(1): 17- 25 (1989), and the Extension Toxicology Network website.

Question: Is glyphosate harmful to human beings?

Answer: There are no risks of concern for glyphosate by itself, from dermal or inhalation routes of exposure, since toxicity is very low. Scientific studies have demonstrated that glyphosate is non- carcinogenic and has no effects on reproductive ability or developmental capacity (see Williams, G.M., Kroes, Rl, and Munro, I.C., "Safety Evaluation and Risk Assessment of the Herbicide Roundup and Its Active Ingredient, Glyphosate, for Humans." Regulatory Toxicology and Pharmacology 31, No. 2/1 (2000)).

However, due to the presence and quantity of an inert (pesticide inactive) ingredient in the formulated glyphosate product concentrate, which was used through most of 2002, there is concern for acute eye irritation. Program workers who handled (mix and load) this product concentrate before it was diluted to make the spray solution would have had the greatest potential for exposure and risk of eye irritation. At the end of 2002, use of this product was discontinued and the program began using a different glyphosate product formulation. Toxicity studies of this product's formula (concentrate) and the diluted tank mixtures (spray solution) gave results of significantly lower eye irritation.

Question: Does glyphosate destroy the soil and prevent plant growth?

Answer: Glyphosate enters a plant through contact with its leaves and only kills plants that are above ground at the time of spraying. In the soil, glyphosate is quickly broken down by microorganisms into naturally occurring compounds such as carbon dioxide. Thus the rejuvenation of plant growth (naturally or through replanting) can begin immediately after spraying. Glyphosate is commonly used by farmers worldwide to prepare fields prior to planting and is used by farmers in Colombia because its application obviates the use of weeding tools that disturb the soil and cause erosion.

Question: Don't legal crops and other plant life get sprayed, too?

Answer: Legal crops are not deliberately sprayed unless they are interspersed with illegal crops. Pilots release the spray only after they have visually identified coca in the flight line. Pilots don't open the valve to release the glyphosate mixture unless they have visual confirmation of coca. Food crops do not get sprayed unless they are intermingled with coca.

Although the Government of Colombia does rely on technology when coordinating which areas to spray, pilots do not spray fields unless they see coca growing there.

The GOC uses an aircraft-mounted global positioning computer system to identify the precise geographical coordinates where illicit crops are being grown. A computer program then sets up precise flight lines (the width of a spray swath) within that area.

Because glyphosate is a broad-spectrum herbicide, it would be expected to be toxic to plants outside the application zone through spray drift. Several measures are taken to control drift. For instance, spray missions are cancelled if wind speed at the airport is greater than 10 M.P.H., if relative humidity is below 75 percent, or if temperature is over 32 degrees Celsius (90 degrees Fahrenheit) - - to avoid drift that might come from a temperature inversion.

Question: Does glyphosate contaminate the water where it is sprayed? Answer: No. Glyphosate bonds tightly to the soil particles and thus is unlikely to leach into groundwater or contaminate drinking water. Colombia's aerial eradication operations avoid spraying bodies of water directly. However, should glyphosate enter water through runoff or erosion, scientific studies indicate that the half-life would be about 7 days in flowing water (rivers) and about 12-60 days in ponds (see Giesy, J.P., Dobson, S., and Solomon, K.R., "Ecotoxicological Risk Assessment for Roundup Herbicide," Reviews of Environmental Contamination and Toxicology 167: 35-120 (2000)).

Question: Is glyphosate dangerous for the environment?

Answer: Glyphosate itself is only slightly toxic to wild birds, practically non-toxic to fish and rapidly decomposes in soil and water.

Question: If glyphosate is so benign, why are there complaints of damage from its use in Colombia?

Answer: Many of these reports are based on unverified accounts by growers whose illicit crops have been sprayed. Because their illegal livelihoods have been affected by the spraying, these persons do not offer objective information about the program. Illegal armed groups are the source of other complaints, since they derive much of their incomes from illicit crops and have a significant interest in fomenting opposition to the spray program. The U.S. Embassy in Bogota investigates all cases of health damage allegedly connected to the spray program, provided that enough detail is provided to permit an investigation. Despite numerous investigations, not a single claim of harm to human health as a result of the spray program has ever been substantiated. These health problems are more likely to be caused by bacteria, parasites, and infections endemic in the remote rural areas where illicit cultivation takes place. Many are also likely caused by exposure to the other pesticides and processing chemicals used by growers of illicit crops or by diseases endemic to the regions.

Question: How are complaints about glyphosate investigated?

Answer: The Government of Colombia has implemented procedures for a more rapid, efficient process for investigating citizens' complaints that legal crops were sprayed in error. Under the new process, complaints will first be examined to determine whether computer flight records indicate that spraying indeed took place in the vicinity on the specified date. This initial check eliminates many of the claims and the rest are investigated in the field. Most cases of spraying of legal crops occur when farmers have planted legal crops within or adjacent to coca or opium poppy. This practice is illegal and compensation is not paid for damage to such crops. Although the spray pilots are experienced and well trained, occasional technical and human errors are unavoidable, so this compensation process is needed to provide a fair, rapid means by which Colombian citizens can seek compensation in these instances.

Question: Is spraying contributing to the deforestation of Colombia? Answer: Damage from deforestation is wrought by drug cultivators who must cut down up to four hectares of forest for each hectare of coca planted, two-and-a-half hectares of forest for each hectare of opium poppy. Coca and poppy growers then poison the surrounding streams and soil with the chemicals used in coca cultivation and narcotics processing. Deforestation is increasing at an alarming rate. It threatens Colombia's rich biodiversity and sustainable agriculture and is increasing the potential for natural disasters such as landslides and floods.

As indicated above, the spraying of coca and opium poppy fields with glyphosate does not harm the soil and allows for the rapid regeneration of native plant species. The aerial eradication program in Colombia, applies glyphosate to fields of coca and opium poppy that have been carved out of the jungle. Spraying a single-crop field in a way that does not harm the soil in fact encourages the natural reintroduction of native species and increases diversity. Aerial eradication, combined with alternative development, discourages the cultivation of illicit crops and thereby slows the rate of deforestation.

Question: Why doesn't the United States Government fund alternative development programs in Colombia instead of spraying illegal crops?

Answer: The U.S. Government is the largest donor to alternative development programs in Colombia, including crop substitution where appropriate, infrastructure construction, environmentally responsible agro-forestry initiatives. Alternative development is an essential part of the solution to the world's illegal drug problem and the U.S. is working closely with Colombia's national plan for alternative development (PNDA). Because democracy and human rights protection are necessary for peace and economic development in Colombia, USAID assistance also includes, among other things, funding for houses of justice (casas de justicia) and assistance to Internally Displaced Persons (IDPs), people forced to leave their homes for other areas of Colombia because of armed conflict. In all, USAID assistance to Colombia in FY02 came to $105 million.

Question: Doesn't the spray program hurt the small farmer who has no other way of earning a living?

Answer: Most coca cultivation in Colombia takes place on a large- scale basis, but smaller fields are often financed by narcotraffickers and are equally illegal. Many Colombians presently suffer from severe economic hardship. This unfortunate fact should not be used by anybody as an excuse to pursue a livelihood that is unlawful, environmentally destructive, and causes further harm to the nation of Colombia. Colombian coca growers are not simply innocent farmers who produce an agricultural product that somebody far away turns into a deadly drug; they are in fact actively engaged in drug production at field-side processing laboratories.

Furthermore, the illegal drug trade contributes to economic destabilization in Colombia by supporting the terrorist groups that cause great harm to the country and development in rural zones in particular.

As of April 2, 2003, this document was also available online at

Search WWW Search

Financial Flows
National Security

Center for International Policy
1717 Massachusetts Avenue NW
Suite 801
Washington, DC 20036
(202) 232-3317 / fax (202) 232-3440