Soybean pod damaged by insects.
Crédito: Maggilautaro – Creative Commons Licence
Endosulfan Ban Highlights Need for Alternatives
Por Marcela Valente
Eliminating the use of the insecticide endosulfan raises the challenge of finding less toxic but effective substitutes.
BUENOS AIRES, May 2 (Tierramérica).- The upsurge in the use of the toxic pesticide endosulfan, targeted for prohibition by the international community, illustrates one of the dilemmas of intensive agriculture in Argentina and Latin America in general.
“There is always a natural solution,” insists farmer Alicia Alem, a member of an Argentine cooperative that produces cereal and forage crops without chemical fertilisers or pesticides.
“In terms of wheat, for example, the cooperative gets exactly the same yield as traditional producers at a lower cost, because we use our own seeds and don’t need to buy a whole battery of chemicals,” Alem told Tierramérica.
Alem forms part of the Association of Family Farmers of Cañuelas Limited, an agricultural cooperative made up of farmers who grow alfalfa, wheat, maize, sorghum and foxtail millet (Setaria italica), a variety of grass, on holdings of between four and 12 hectares each in the town of Cañuelas, 60 kilometres northeast of Buenos Aires.
The cooperative owns silos, a mill, a harvester and other machinery. But all pest control is 100 percent biological, based on the use of insects that are natural predators, through methods that vary depending on the pests and crops in question. “If a problem arises, we seek assistance from public institutions,” said Alem.
The cooperatives achieve good yields without polluting the environment or endangering human health, although the work is much more time-consuming. “Agro-ecological production requires more observation, more physical labour. It is less mechanised. But it doesn’t kill,” she commented.
Poisoning from toxic agrochemicals is one of the leading causes of illness and death in agricultural areas and heads the list of work-related accidents in many countries.
Alternative methods like those used by the Cañuelas cooperative would make it possible to give up chemical substances like endosulfan, an organochlorine insecticide and acaricide used on a wide range of crops in the region, including cereal and forage crops, legumes, garden vegetables, flowers, tobacco, sugar cane, coffee and cotton.
One of the most toxic pesticides on the market, endosulfan causes acute and chronic poisoning. It affects the nervous and immunological systems and disrupts hormonal balance.
In Argentina, almost two million tons of endosulfan were sold in 1999. By 2006, sales had jumped to 4.2 million tons, mainly due to the sharp increase in the production of soybeans, which had come to account for more than half of the land under cultivation in the country, according to the Chamber of Agricultural Health and Fertilisers.
Soybeans are also a major crop in Brazil, Uruguay and Paraguay, where they are cultivated through direct sowing and the intensive use of a variety of toxic agrochemicals.
Endosulfan combats over a dozen insects that affect soybean crops. However, while eliminating undesirable insects, it also kills their natural predators, organic farmers maintain.
Already banned in more than 75 countries, endosulfan is classified as a “highly toxic” substance by the United States Environmental Protection Agency. Since 2007, the European Union has been calling for its inclusion among the so-called “dirty dozen”.
These are the 12 persistent organic pollutants (POPs) whose gradual elimination was established as a priority by the Stockholm Convention, an international treaty signed in 2001 and effective from May 2004 that aims to eliminate or restrict the production and use of POPs.
In 2009, the parties to the Convention agreed to add nine new substances to the original list of 12.
POPs are toxic organic compounds that are resistant to environmental degradation. They accumulate in the fatty tissues of living organisms and food chains, and can travel long distances.
The addition of endosulfan to the list of banned substances was one of the main issues on the agenda of the fifth meeting of the Conference of the Parties to the Stockholm Convention, held Apr. 25-29 in Geneva.
India presented the fiercest opposition to the prohibition of endosulfan, while countries like Argentina, Peru and Chile demanded technical and financial assistance to make the transition to alternative substances.
The question of alternatives involves a number of different facets, agricultural engineer Javier Souza of the Centre for Studies on Appropriate Technologies in Argentina told Tierramérica.
“Some chemicals offer an intermediate solution, a lesser evil in the short term, but for the long term we need to aim at the development of production systems that don’t depend on chemical insecticides,” he said.
In fact, a number of pesticides introduced four years ago to replace POPs targeted for elimination are now being questioned, with some recommending that they be banned as well, as in the case of sulfuramide.
Souza, who is also the coordinator of the Action Network on Pesticides and Alternatives for Latin America (RAP-AL) – the regional centre of the Pesticide Action Network (PAN) – stressed that endosulfan has already been replaced in Brazil, Colombia, Paraguay Venezuela and a number of Caribbean countries.
The government of Argentina resolved to go along with the consensus on endosulfan in Geneva, and Argentine pesticide manufacturers have announced that they will abide by whatever is decided at the conference. “The thing is, in addition to being toxic, endosulfan is proving to be rather inefficient,” explained Souza.
Traditional cotton growers in the northeastern province of Chaco use endosulfan to combat boll weevils (Anthonomus grandis Boh.), which can wipe out entire crops.
According to Souza, the growers have commented that these insects are becoming more and more resistant to the product, which means that ever larger quantities need to be used, increasing the health risks involved.
RAP-AL advocates preserving biodiversity, including the preservation of the habitat of insects that are natural parasites and pesticides, and using organic fertilisers.
“Natural fertilisation and the preservation of biodiversity create crops that are more resistant to pests and disease,” said Souza.
On the other hand, the expansion of monoculture plantations of a single crop decreases biodiversity, alters the trophic relations of insects, and makes crops more vulnerable, he said.
Progress in the right direction will require the kind of political will that began to emerge in Geneva. “If the Ministry of Agriculture provided the same support for agro-ecological production as for traditional production, things would be very different,” he concluded.