Review of Cicad, Organization of American States Report

“Production of Illicit Drugs, the Environment and Human Health” : August 2009

In February 2004, the Organization of American States (OAS) through the Inter-American Drug Abuse Control Commission (CICAD), commissioned a study on the effects of glyphosate use for coca and opium poppy eradication in Colombia.  The study was led by highly-respected ecotoxicologist Prof. Keith R. Solomon from the University of Guelph, Canada.  The first expert panel report, a review of the extensive scientific literature on glyphosate, appeared in 2005.  The panel concluded that the spray formulation posed little risk to humans or wildlife.  A second set of follow-up experiments was initiated to study sensitive amphibians (specifically frogs) as well as humans potentially exposed in the regions of coca spraying.  These reports were published electronically on August 11, 2009, as nine peer-reviewed papers in Volume 72 of Journal of Toxicology and Environmental Health, Part A (http://www.informaworld.com/smpp/title~db=all~content=g913842708).  Financing of the study was by the Governments of Colombia and the United States.  Both sets of studies will likely figure prominently in the lawsuits against Dyncorp in U.S. Federal Court and the Government of Colombia at the International Court of Justice for alleged damage in Ecuador caused by the aerial eradication program.

The following summary explains the results of the latest CICAD studies on the risks associated with the drug crop eradication program in Colombia.

Executive Summary: 

Glyphosate spraying for coca control in Colombia poses negligible risk to humans and the environment.  While some technical changes were suggested, they mainly concern potential enhancement of herbicide efficacy, not issues of safety.

Detailed Summary:

A.  Spray Droplets and Drift.  A key study dealt with the potential for downrange drift of the herbicide formulation during aerial eradication operations.  Sophisticated wind tunnel studies were conducted in Austra¬lia using the same type of spray mixture, nozzle, and speeds as with coca and poppy aerial spraying in Colombia.  Mathematical modeling allowed additional parameters to be simulated.  The study reported that spray droplets were fine at an AT-802 spray aircraft’s simulated typical speed of 170 mph. The faster OV 10 aircraft produced very fine droplets and the slower Turbothrush T-65 gave the largest droplets due to less wind shear.  (Note that the spray program currently only uses AT-802s for aerial spray operations.)  While simulated drift studies showed that spray drift may impact vegetation immediately adjacent to targeted coca fields, the authors concluded that the long-distance drift of spray particles is small and not an issue for humans or the environ¬ment beyond 50 meters downwind at the maximum permitted wind velocity of 9 km/hour for spraying operations.  The authors of this study acknowledge that spray conditions in Colombia afford great reduction in spray drift potential through interception of spray droplets by leaf and other surfaces.

B.  Field Tests of Glyphosate and Adjuvants for Coca Control.  The authors tested up to five adjuvants with three rates of three glyphosate formulations on young coca plants.  Glyphos + Cosmo-Flux (similar to the current mixture used in aerial eradication operations) gave the best early control symptoms at 3 weeks.  Several herbicide-adjuvant combinations resulted in statistically comparable control of coca plants as the Glyphos + Cosmo-Flux combination.  These findings do not warrant changes in spray strategy based on this alone.  The higher rate (4 kg/ha) was superior to lower rates.

C.  Toxicity Amphibians.  Researchers looked at the toxicity of the spray formulation on amphibians, an especially vulnerable part of the ecosystem.  Research was conducted by a Colombian-Canadian scientific team and showed that:  (i) Cosmo-Flux, the adjuvant used in the current spray formulation, does not enhance glyphosate toxicity; (ii) mortality rates of tadpoles greater than 50 percent occurred only when glyphosate—Cosmo-Flux rates were more than twice that applied in the aerial eradication of coca; (iii) toxicity is greatly reduced with the introduction of real-world conditions such as sediment and (iv) tests with terrestrial frogs under realistic conditions confirmed that “under worst-case exposure conditions, the mixture of Glyphos and Cosmo-Flux used for control of coca in Colombia is of low or negligible risk to aquatic and juvenile terrestrial stages of frogs.”

Using comparable worst-case scenarios, the researchers found the toxicity risk from coca production chemicals used by growers to be up to 10- to 100-fold more toxic to frogs than was the Glyphos−Cosmo-Flux coca eradication mixture.  “The cumulative impacts of coca production, through habitat destruction, application of agrochemicals, and potential transmission of disease, are judged to pose greater risks to amphibian populations in coca-growing regions than the glyphosate spray control program.”

Humans.  A Colombian-Canadian-British team conducted epidemiological studies of 2,592 women in Magdalena, Boyacá, Valle del Cauca, Nariño, and Putumayo Departments of Colombia, spanning regions with and without potential exposure to coca or poppy aerial eradication spraying. The researchers found that reduced fecundability (delayed time to first pregnancy) was not associated with glyphosate use for drug crop eradication.  The data covered November 1999 to February 2005.

From the same five regions, biomonitoring of genotoxic risk was conducted on 137 couples who work in rural agriculture and risk exposure to the herbicide used during aerial eradication operations between October 2006 and December 2007.  Testing of these couples was to determine whether specific chromosomal damage had occurred as a result of cumulative exposure to some genotoxic agent.  There was no association of genetic damage and purported exposure to glyphosate from illicit crop spraying.