Researchers: Rodrigo R. Soares with Mateus Dias and Rudi Rocha

Glyphosate is today the most used herbicide in the world. Developed in 1970 by Monsanto and first commercialized in 1974, under the name Roundup, it is a systemic, non-selective, foliar applied herbicide. Its suitability for use with genetically modified crops explains its rapid adoption by farmers over the last few decades, following the expansion in the use of genetically modified seeds, in particular of the glyphosate resistant soybean (also developed by Monsanto and commercialized under the name Roundup Ready Soybean). Despite public controversy on its widespread use, and some laboratory evidence on the damaging effects of glyphosate on human cells, there is currently no direct evidence on whether the use of glyphosate at the levels typically seen in agriculture is indeed harmful to human populations, and particularly so to individuals not directly involved in its handling and application. The goal of this project is to assess the impact of glyphosate use on the health of human populations. This is a major issue in the current debate on the use of glyphosate and, more generally, of genetically modified seeds. In Brazil, the use of glyphosate is concentrated on the production of soybeans and increased with the expansion of soybean planted area following the adoption of genetically modified seeds in the 2000s. The project uses this setting to analyze the effect of expansion on the use of glyphosate on human health. This analysis presents a couple of empirical challenges. First, the effect of glyphosate on health may be cumulative and vary over long horizons of time. For this reason, the researchers will focus on the health of newborns, for whom the period of exposure is clear and well defined. Second, expansion of soybean production and glyphosate use may impact health through other channels, such as increased income, and may also be related to other characteristics of local farmers (associated with modernization). For this reason, the researchers will explore the set of municipalities sharing the same water resources (Ottobasin) and look at how the use of glyphosate in neighboring municipalities affects a given municipality that shares water resources with them. They hope that the project will make an important contribution to the ongoing debate on the potential trade-offs implicit in the use of glyphosate in agriculture.