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  • Aerial spraying of herbicide 'damages DNA'


[BOGOTA] Aerial spraying of a herbicide by the Colombian government on the border of Colombia and Ecuador has caused a high degree of DNA damage in local Ecuadorian people, according to a study. 

The research will be published in the next issue of Genetics and Molecular Biology.

The scientists, from the Pontificia Catholic University in Ecuador, analysed blood samples from 24 Ecuadorians living within three kilometres of the border of the two countries. Aerial spraying of a herbicide formulation containing glyphosate ― sold under the name Roundup by Monsanto ― took place on the Colombian side of the border between late 2000 and early 2001.

The Colombian government sprays illegal coca plantations ― used to make cocaine ― as part of its 'war on drugs'.

According to the paper, the application rate of the herbicide (litres per hectare) was 20 times the maximum recommended rate for the formulated product.

Half the individuals in the group received spraying directly over their houses, and the blood samples were taken within two months of the spraying taking place.

For comparison, blood samples were taken from 21 Ecuadorian individuals living 80 kilometres away from the border, where aerial spraying of the herbicide formulation did not take place.

In addition to expected symptoms ― including vomiting and diarrhoea, blurred vision, and difficulty in breathing ― the researchers found a significantly higher degree of DNA damage ― 600 to 800 per cent higher ― in the people living near the border compared with those 80 kilometres away.

The researchers ruled out tobacco, alcohol, non-prescription drugs and asbestos as causing the DNA damage. None of the individuals used or had been exposed to other herbicides or pesticides when the samples were taken.

DNA damage may activate genes associated to the development of cancer, lead researcher Cesar Paz y Miño told SciDev.Net, and may also lead to miscarriage or malformations in embryos.

Both Colombia and Ecuador have formed national scientific and technical commissions to study the effects of aerially spraying this herbicide formulation, with the Ecuadorian commission concluding it does affect humans and the Colombian commission refuting this claim (see Pesticides used in Colombian war on drugs 'not harmful').

President of the Colombian commission, Alberto Gómez Mejía, told SciDev.Net that it is difficult to establish the real cause of the effects of agrochemicals in humans.

Reference: Genetics and Molecular Biology 30, 456 (2007)

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