Studies Find DNA Damage From Anti-Coca Herbicide
By Stephen Leahy
Saturday 16 June 2007
Toronto – U.S.-funded aerial spraying of coca plantations in Colombia near the Ecuador border has severely damaged the DNA of local residents, a new study has found.
Blood samples from 24 Ecuadorians living within three kilometres of the northern border had 600 to 800 percent more damage to their chromosomes than people living 80 km away, found scientists from the Pontificia Catholic University in Quito, Ecuador.
The border residents who were tested had been exposed to the common herbicide glyphosate – sold by the U.S. agribusiness giant Monsanto under the brand Roundup – during a series of aerial sprayings by the Colombian government begun in 2000, part of the anti-drugs and counterinsurgency Plan Colombia, financed by Washington.
The Ecuadorians suffered a variety of ailments immediately following the spraying, including intestinal pain and vomiting, diarrhoea, headaches, dizziness, numbness, burning of eyes or skin, blurred vision, difficulty in breathing and rashes, says the study, which is to be published in the journal Genetics and Molecular Biology.
But the extensive damage to DNA (deoxyribonucleic acid) found in the randomly selected individuals may activate the development of cancer or other developmental effects resulting in miscarriages, according to lead researcher César Paz y Miño, head of human molecular genetics at the Catholic University of Ecuador.
In general, everyone has some level of DNA damage due to exposure to ultraviolet radiation, air pollution, toxic chemicals and other factors. However, none of the 24 randomly-selected individuals used tobacco, alcohol or non-prescription drugs, nor did they use other herbicides or pesticides that could have caused the extensive DNA damage observed, Paz y Miño told Tierramérica.
The concentration levels of Roundup were measured at more than 20 times the maximum recommended rate and may be the reason behind the genotoxic (capable of causing genetic mutation) effect on the exposed individuals, he said.
The blood samples were collected by Spanish doctor Adolfo Maldonado, of the non-governmental Acción Ecológica, which since the beginning of this decade has been studying health, economic and social problems of Ecuadorian populations affected by the aerial herbicide spraying in neighbouring Colombia.
Washington has been financing since 2000 the aerial spraying in Colombia of coca crops – the raw material of cocaine, of which Colombia is the world’s leading producer. In the past three years it has spent more than 1.3 billion dollars to combat the drug trade.
In 2006, the Colombian National Police’s Anti-Narcotics Directorate (DIRAN) sprayed 171,613 hectares of illicit coca and opium poppy, according to a March 2007 International Narcotics Control Strategy Report released by the U.S. State Department.
The extent of aerial spraying has increased every year since 2000, with 24 percent more in 2006 than 2005.
Three aerial spraying units, funded and operated by the United States, work full-time in Colombia, and a fourth unit was added in 2006, the report notes.
Aerial spraying “follows strict environmental safeguards, monitored permanently by several GOC (government of Columbia) agencies,” it says.
As for impacts on health, “the Colombian National Institute of Health has not verified a single case of adverse human health effects linked to glyphosate spraying,” states the report.
Paz y Miño disputes that assertion. In addition to his own study, there are studies from the University of the Andes and from the National University of Colombia that also “report the damage that the aerial sprayings produces in Colombians”, he said.
In fact, since 1994 there have been many studies that show potential health impacts of Roundup on people and wildlife, he said.
Roundup is a mixture of glyphosate and other chemicals designed to increase the herbicide’s penetration into plants or boost its toxic effects.
But only glyphosate – the active ingredient – has been fully tested by U.S. regulators for its health and environmental effects.
In 2005, a team of French scientists headed by Gilles-Eric Seralin reported that Roundup was toxic to human placental cells within hours of exposure, at levels 10 times lower than those found in agricultural use.
Just last month, Seralin reported new findings which show that even diluted up 10,000 times, the chemical disrupted hormone production in placental cells.
“This work may be of help in better understating the problems of miscarriages, premature births or sexual malformations of babies,” Seralin said in a statement.
In April of this year, DNA damage was also documented by Turkish scientists at Mersin University. The DNA of fish was damaged even at extremely low levels of five to 15 parts per million of Roundup.
“There is no doubt that the spraying programme is killing amphibians in Colombia,” said Rick Relyea, a biologist at the University of Pittsburgh, in the north-eastern U.S. state of Pennsylvania.
In 2005, Relyea documented that Roundup was lethal to frogs. More than 90 percent of the tadpoles exposed to small doses were killed by a chemical called polyethoxylated tallowamine (POEA), which is part of normal Roundup formulation. POEA allows glyphosate to penetrate plant leaves.
Experiments with frogs in the United States showed that “more than 80 percent of the adults exposed to Roundup spray at normal rates died in a day.” There is no data about the impacts of the spraying of Colombian frogs and amphibians.
Those findings prompted the U.S. Congress to obtain guarantees in 2006 that wetlands would not be sprayed in Colombia, Relyea told Tierramérica.
However, most frogs live in small wetlands that aren’t easily detected from the air and many species in the region are found in trees and grasslands, he said.
As Roundup is the most widely used herbicide in the world, it may be a factor the dramatic global decline in frogs, but there is no firm proof, Relyea says.
But there is ample proof of the effects of aerial spraying along the Ecuadorian border, says Paz y Miño.
Destruction of legal crops, death of domestic animals and fish in hatcheries, in addition to the human health impacts have all been documented.
His research group is finishing a new set of studies on the effects of glyphosate, alone or with POEA, on insects and in vitro cultured human cells, he said.
“I could tell you, in advance, that we have found (genetic) damage in these.”