In contrast, the study shows that environmental pollution from such chemicals is not nearly as severe as once believed.
An international team of scientists working in the highlands of Ecuador found that highland soils can absorb large amounts of insecticides. As a result, the researchers sat that the chemicals pose less of a threat to groundwater than they might at other locations.
But the large percentage of Ecuador's population engaged in agriculture and a lack of information about the hazards involved in handling toxic chemicals increase the risk to human health.
"Comparing agriculture with environmental objectives or with human health is a little like adding apples and oranges," says one of the researchers, Charles Crissman, an agricultural economist at the Peru-based International Potato Centre.
"Yet that's precisely the type of policy analysis that's needed to make sense of the conflicting objectives involved in sustainable agriculture."
The study concludes that the best way to improve health while preserving farmer's income is to use integrated pest management (IPM). This involves combining improved farming and biological control practices with the judicious use of commercial insecticides.
Crissman says that the Ecuadorian government should ban the most toxic insecticides and strengthen health-monitoring systems. "By reducing the reliance on the most toxic insecticides, IPM would render the cost of these changes insignificant compared with the long-term benefits," he says.
Educating farmers about the dangers of pesticides is also essential, the study concludes. Crissman says that one survey showed that less than 15 per cent of workers who applied insecticides knew that a container carrying a red label marked with a skull and cross bones meant that it contained dangerous material.
The study used a new policy analysis tool known as the Tradeoff Analysis Model. This integrates computer models from different disciplines in an attempt to help decision makers weigh the complexities of issues at the intersection of agriculture, environment and human health.
"We need to deal with the complex interactions among all of the organisms in the environment, and begin working toward integrating a variety of approaches," says Crissman.
"The real value of the Tradeoff Analysis Model is that it allows you to combine hard scientific data from a variety of sources, compare them, and begin to see what you gain and what you lose when you change public policy."
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