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19th Discussion Forum on Life Cycle Assessment of Pesticides

ETH-Zürich, 27 March 2003

Abstract title:

Life Cycle Impacts on Human Health and Ecosystems of the Mostly Used Pesticides in Costa Rica.

Authors and affiliations:

Sébastien Humbert, Olivier Jolliet

Swiss Federal Institute of Technology of Lausanne (EPFL), Institute of Environmental Science and Engineering, CH-1015 Lausanne

Short description:

In many developing countries, that largely depend on agricultural exportations, pesticides which have been forbidden in developed countries are still being applied in relatively large quantities. It is therefore important to assess if more sustainable alternatives and pesticides are available to ensure similar functions.

This study analyses the life cycle impacts on human health and ecosystems of more than 80 active substances used in Costa Rica.

The impacts of the 31 active substances mostly used in Costa Rica were studied based on the latest available amounts used in 1998, using the fate-effect model IMPACT 2002. Results show that more than 80% of the impacts on the ecosystems appears to be due to only 3 active substances (namely cypermethrin, carbendazim and chlorothalonil) whereas they represented less than 10% of the amount used. Also, more than 90% of the human health impact appears to be due to only 5 active substances (namely methyl bromide, terbufos, terbutryn, diazinon and methamidophos) whereas they represented less than 20% of the amount used.

In addition, the impacts of more than 50 other active substances used in Costa Rica were studied. Feasible-substitutions within these active substances were proposed. For instance, potential replacement of terbufos by deltamethrin and terbutryn by bentazone were assumed. Following UNEP propositions, methyl bromide could be replaced by metam sodium. Hence, while focalizing on only four or five active substances, it is possible to achieve a 50% reduction of human health and environmental impacts due to pesticides use in the country.

This type of study should enable to identify the most harmful substances and to propose substitutions that achieve high reduction of impacts.

Sébastien Humbert

GECOS-EPFL-Switzerland / CGR-Costa Rica, 30 January 2003