THIRD WORLD NETWORK BIOSAFETY INFORMATION SERVICE
Dear Friends and Colleagues
High Glyphosate Residues on GM Soybean, but Risk Assessment Inadequate
About 77% of the global soybean production comes from glyphosate-tolerant (GT) soybean and the dominant soy producing countries of Brazil, USA and Argentina have a 94%–100% adoption rate of genetically engineered crops, mostly GT. GT soy constituted 270 million metric tonnes out of the 349 million metric tonnes of soy produced in the 2016–2017 season.
Research has shown that GT soybeans accumulate herbicides, have altered nutritional composition, and cause dose-related adverse effects in feeding studies in a relevant model organism. A new study reports that farmers have doubled their glyphosate applications per season (from two to four) and that residues of late season spraying of glyphosate resulted in much higher residues in the harvested plants and products. In addition, commercial farm samples of GT soybeans contain far higher concentrations of glyphosate compared to GT soybeans from field trials that were used for safety assessments.
The study estimated that GT soybeans produced on commercial farms in the USA, Brazil and Argentina accumulated a total of 2,500–10,000 metric tonnes of glyphosate per year, which enter global food chains. Farm samples from Brazil showed average residue levels of glyphosate at 38.5 mg/kg, nearly twice as high as the maximum accepted residue level specified by Codex and the EU. In Argentina, average and maximum residue-levels were measured at 31.7 mg/kg and 72.8 mg/kg, respectively.
The impacts of such high residues of glyphosate constitute knowledge gaps that have entailed incomplete evaluations on potential interactions between glyphosate residues and plant composition, and potential negative effects on consumers. The current risk assessment system has only required and received data from field trials with beans that were sprayed with much lower doses of glyphosate as compared to commercial farms. The researchers argue that GT soybeans need to be tested in fully representative and realistic contexts and that proper long-term in vivo feeding studies are needed.
With best wishes,
Third World Network
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Malaysia
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THE INTRODUCTION OF THOUSANDS OF TONNES OF GLYPHOSATE IN THE FOOD CHAIN—AN EVALUATION OF GLYPHOSATE TOLERANT SOYBEANS
Bøhn, T., & Millstone, E.
Foods 2019, 8(12), 669
https://doi.org/10.3390/foods812066
11 Dec 2019
https://www.mdpi.com/2304-8158/8/12/669
Abstract
Glyphosate-tolerant (GT) soybeans dominate the world soybean market. These plants have triggered increased use of, as well as increased residues of, glyphosate in soybean products. We present data that show farmers have doubled their glyphosate applications per season (from two to four) and that residues of late season spraying of glyphosate (at full bloom of the plant) result in much higher residues in the harvested plants and products. GT soybeans produced on commercial farms in the USA, Brazil and Argentina accumulate in total an estimated 2500–10,000 metric tonnes of glyphosate per year, which enter global food chains. We also review studies that have compared the quality of GT soybeans with conventional and organic soybeans. Feeding studies in Daphnia magna have shown dose-related adverse effects (mortality, reduced fecundity and delayed reproduction) of glyphosate residues in soybeans, even at glyphosate concentrations below allowed residue levels. We argue that GT soybeans need to be tested in fully representative and realistic contexts. However, the current risk assessment system has only required and received data from field trials with beans that were sprayed with much lower doses of glyphosate as compared to contemporary commercial farms. This has left knowledge gaps and a potentially serious underestimation of health risks to consumers.
Conclusions
Research has shown that GT soybeans (i) accumulate herbicides, (ii) have altered nutritional composition, and (iii) cause dose-related adverse effects in feeding studies in a relevant model organism. Moreover, data in the scientific literature show that (i) glyphosate residues are substantially increased when herbicides are applied late in the growing season, (ii) commercial farm samples of GT soybeans contain far higher concentrations of glyphosate compared to GT soybeans from corporate field trials (which were used for safety assessments), and (iii) the total amount of glyphosate introduced into the food chain from GT soybeans adds up to thousands of metric tonnes. The impacts of those residues of glyphosate constitute knowledge gaps that have entailed incomplete evaluations on (i) potential interactions between glyphosate residues and plant composition and (ii) potential negative effects on consumers. These issues are not followed up with proper long-term in vivo feeding studies.