Analysis of herbicide-residues is essentially missing in risk-assessment of herbicide-tolerant genetically modified cultivars

Journal or Publishing Institution: Environmental Sciences Europe

Study: https://web.archive.org/web/20180718152306/https://munin.uit.no/bitstream/handle/10037/7869/paper_V.pdf?sequence=7&isAllowed=y

Author(s): Cuhra, M.

Article Type: Journal Publication

Record ID: 427

Abstract: Background. Genetically modified glyphosate-tolerate cultivar varieties (GM-crops) have been a commercial success widely known as Roundup-ready plants. As new glyphosate-tolerant varieties are introduced to satisfy agriculture demand, it is relevant to review the scientific evidence that documents the quality and safety of such biotechnology. Assessment of genetically modified glyphosate-tolerant plants is partly based on reports from laboratory comparisons with non-modified plants (near isogenic relatives). Such comparative testing is typically performed as analysis of plant-material composition and in animal feeding studies. The material for testing is typically produced in test-fields set up as model-environments. Researchers employed by biotech industry companies plan, perform and report most of this research.

Perspective. The present paper aims to; i) review 15 reports on compositional analyses of glyphosate-tolerant cultivars and 15 reports from animal-feeding-studies, ii) discuss recent data indicating glyphosate residue in Roundup-ready-soybean, iii) outline recent developments of cultivars with increased tolerance to glyphosate.

Findings. The reviewed industry studies show methodological flaws: Glyphosate-tolerant GM-crops are designed for use with glyphosate herbicide. However, glyphosate hericides are often not applied in test-study cultivation. In the studies where glyphosate herbicides were applied to growing plants, the produced plant material was not analyzed for glyphosate residues. This review has failed to identify industry studies that mention glyphosate residues in glyphosate-tolerant plans. This indicates that questions and evidence of importance for regulatory assessment have been systematically ignored. Independent research has investigated this issue and found that glyphosate -tolerant plants accumulate glyphosate residues at unexpected high levels. Glyphosate residues are found to have potential to affect plant material composition. Furthermore, these residues are passed on to consumers.

Conclusions. Industry studies are not sufficient for regulation. Despite decades of risk assessments and research in this field, specific unanswered questions relating to safety and quality aspects of food and feed from transgenic cultivars need to be addressed by regulators. Independent research gives important supplementary insight.

Keywords: Genetically modified cultivar varieties (GM-crops), Roundup-ready plants, glyphosate-tolerant, animal-feeding studies, risk assessment

Citation: Cuhra, M. (2015). Analysis of herbicide-residues is essentially missing in risk-assessment of herbicide-tolerant genetically modified cultivars. Environmental Sciences Europe.