Aerial spraying devastates Colombian communities

Indigenous peoples in the Amazon are urgently calling for an end to the aerial spraying of herbicides, part of the US-funded anti-drugs tactics in Colombia, because it is destroying their communities. How can one of the world's most widely used and 'safest' weedkillers produce such shocking impacts?

Impact of the US-backed drugs eradication programme
Herbicides have been used by the Colombian government for many years as part of the eradication programme for drug crops but the intensity of aerial spraying has greatly increased under the US$1.3 billion US-funded Plan Colombia which aims to wipe out drug production at source by destroying coca and poppy crops (the plants used to make cocaine and heroine respectively). Over 40,000 ha of land have been sprayed by air in Colombia's southern region of Putumayo since December 2000 using the broad-spectrum herbicide product Roundup, based on the active ingredient glyphosate(1).
    The US State Department and Colombian authorities claim that herbicide application is precision-targeted at 'illicit' crops using satellite imagery to guide the crop-dusting planes. However, evidence from the ground and from local commentators shows that herbicide spray falls directly onto nearby food crops, water sources, livestock and natural vegetation. It is impossible for even experienced pilots to avoid spray drift onto the communities living in these semi-jungle areas and there have been cases of herbicide fall-out on homes, schools and directly onto adults and children. 
    In complaints received by the Colombian Human Rights Ombudsman's Office, smallholder farmers in the aerial spraying zones have reported total destruction of some food crops and herbicide damage to more than 7,000 ha of land in the period December 2000 to February 2001. Crops affected include plantain, cassava, maize, and pasture. Environmental damage is not quantified but the eradication zones coincide with the sources of three major rivers and a UNESCO World Heritage Site.
    Even more alarming have been the effects of aerial spraying on humans and livestock. Data reported from Putumayo include 4,289 people and 178,377 animals affected during this period. Hospital staff have observed a notable increase in medical consultations for serious skin and eye irritation, acute respiratory problems, diarrhoea and vomiting since the intensified spray regime started, with some children suffering severe skin lesions which failed to heal properly. In July a Bogota newspaper reported that over 35,000 indigenous people had been made ill as a result of the spraying.

Increased toxicity and exposure
While glyphosate has a relatively low acute toxicity to mammals (classified by World Health Organisation (WHO) as 'unlikely to present acute hazards under normal use' for oral toxicity and 'slightly hazardous' for dermal toxicity, concerns have been raised over inconsistencies between laboratory-derived data and toxicity data from field exposure incidents. 
    Biologist Dr Elsa Nivia, Director of the PAN group in Colombia, has used toxicological data from Monsanto and other glyphosate manufacturers, US EPA and WHO sources and data from the aerial spraying programme in Colombia to explain the discrepancies between safety claims for glyphosate products and the experiences of the affected communities(2). Firstly, the surfactants used in glyphosate formulations to increase the adherence to plant surfaces, mainly polyoxy-ethylenamine (POEA), are considerably more toxic than glyphosate itself. Tests on laboratory rats shows POEA can cause serious irritation to the respiratory tract(3). Dr Nivia estimates that POEA in the Roundup formulation used in Colombia could be five times more toxic in terms of oral exposure than glyphosate.
    Secondly, she questions the applicability to humans of conclusions drawn from toxicological testing of glyphosate products on rats. Dr Nivia has analysed data from the scientific literature on fatal cases of human poisonings by Roundup ingestion and calculated that the quantities of Roundup ingested in terms of mg per kg bodyweight appear to be up to 22 times more toxic to humans than rats for glyphosate and up to five times more toxic for POEA. These calculations may help explain why Roundup frequently features in reports of occupational poisoning in many countries despite the low WHO toxicity rating of glyphosate.
    Thirdly, increased concentrations of glyphosate and other ingredients are used in the Roundup formulation applied by the eradication programme. The Roundup product used by most Colombian farmers contains 41% of the technical active ingredient, while the product used in the eradication programme, Roundup Ultra, contains 43.9%. In addition, the programme is using another surfactant, Cosmo-Flux 411F, reported to increase the biological action of glyphosate by a factor of four. 
    Finally, the dosage and intensity of aerial spraying carried out greatly increases exposure. Information from the eradication programme indicates that spray planes deposit, in effect, a 26% concentration of glyphosate, compared to 1% as recommended in the US for weed control in crops. 
    If a four-fold activity increase due to CosmoFlux is also factored into the calculations, then relative exposure levels to Roundup's biologically active components could be up to 104 times greater than in normal agricultural practice. Local inhabitants have seen planes spraying several times over the same fields, further increasing deposition.

Calls to halt spraying
Colombia's Human Rights Ombudsman has rightly called for application of the precautionary principle and suspension of spraying until a full health and environmental assessment can be made. One Bogota judge ordered a suspension of spraying in July, arguing that it violated the right to life and environmental rights of the indigenous communities affected, but this has since been appealed against. The non-target effects of Roundup aerial application on human health and livestock reported to date by Colombians are extremely serious and demonstrate vividly major shortcomings in the extrapolation of standard toxicological data into safety assessments. Moreover, by harming health and destroying food crops, aerial spraying serves only to undermine any efforts to build alternative sustainable livelihoods for indigenous and other communities in the coca-producing areas. PAN UK joins the calls for an immediate halt to aerial applications and for a full, independent impact assessment to be carried out. (SW)

Dr Elsa Nivia can be contacted on rapalmira@telesat.com.co. Information on the social, ethical and political aspects of the aerial spraying can be found at www.usfumigation.org/ 

1. Action Alert: Stop aerial fumigation program in Colombia, PANUPS, 11 July 2001.
2. Aerial spraying of illicit crops is dangerous- some approximations. Elsa Nivia, Paper presented in Spanish to the conference Wars in Colombia: Drugs, Guns and Oil, University of California, Davis, 17-19 May 2001
3. AM Aishah et. al., Oral and intratrachael toxicities of Roundup and its components to rats, Veterinary & Human Toxicology, 1997(3):147-151.

[This article first appeared in Pesticides News No. 53, September 2001, page 9]