Review of GMO safety assessment studies: glyphosate residues in Roundup Ready crops is an ignored issue

Source at http://dx.doi.org/10.1186/s12302-015-0052-7Background - Genetically modified glyphosate-tolerant cultivar varieties 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. Assessments of genetically modified glyphosate-tolerant plants are partly based on the 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. Most of this research is planned, performed and reported by researchers employed by biotech industry companies. Perspective - The present paper aims to: (1) review 15 reports on compositional analyses of glyphosate-tolerant cultivars and 15 reports from animal feeding studies, (2) discuss recent data indicating glyphosate residue in Roundup Ready soybean, (3) 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 herbicides 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 plants. 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 GM crops need to be addressed by regulators. Independent research gives important supplementary insight

Clone- and age-dependent toxicity of a glyphosate commercial formulation and its active ingredient in Daphnia magna.

This article is part of Marek Cuhra's doctoral thesis which is available in Munin at http://hdl.handle.net/10037/7869Low levels of glyphosate based herbicide induced significant negative effects on the aquatic invertebrate Daphnia magna. Glyphosate herbicides such as brands of Roundup, are known to be toxic to daphnids. However, published findings on acute toxicity show significant discrepancies and variation across several orders of magnitude. To test the acute effects of both glyphosate and a commercial formulation of Roundup (hereafter Roundup), we conducted a series of exposure experiments with different clones and age-classes of D. magna. The results demonstrated EC50 (48) values in the low ppm-range for Roundup as well as for the active ingredient (a.i.) isopropylamine salt of glyphosate (glyphosate IPA) alone. Roundup showed slightly lower acute toxicity than glyphosate IPA alone, i.e. EC50 values of 3.7–10.6 mg a.i./l, as compared to 1.4–7.2 mg a.i./l for glyphosate IPA. However, in chronic toxicity tests spanning the whole life-cycle, Roundup was more toxic. D. magna was exposed to sublethal nominal concentrations of 0.05, 0.15, 0.45, 1.35 and 4.05 mg a.i./l for 55 days. Significant reduction of juvenile size was observed even in the lowest test concentrations of 0.05 mg a.i./l, for both glyphosate and Roundup. At 0.45 mg a.i./l, growth, fecundity and abortion rate was affected, but only in animals exposed to Roundup. At 1.35 and 4.05 mg a.i./l of both glyphosate and Roundup, significant negative effects were seen on most tested parameters, including mortality. D. magna was adversely affected by a near 100 % abortion rate of eggs and embryonic stages at 1.35 mg a.i./l of Roundup. The results indicate that aquatic invertebrate ecology can be adversely affected by relevant ambient concentrations of this major herbicide. We conclude that glyphosate and Roundup toxicity to aquatic invertebrates have been underestimated and that current European Commission and US EPA toxicity classification of these chemicals need to be revised

Ecotoxicological assessment of Roundup-ready soybean agriculture investigated in a D. magna model

Transgenic glyphosate tolerant soybeans are constituents of an industrial production system with specific agricultural practices and supplementary agrochemicals as interwoven additional elements. Thus the material produced should not be seen as an isolated product of a specific modified genotype but rather as a product of a tailored agriculture system. This globally dominant crop has been in open cultivation since 1995 and is still predominantly based on hybrid varieties of the GTS-40-3-2 transgenic event soybean (Roundup-ready soybean) in combination with glyphosate herbicide co-technology. The herbicides were tested for acute and chronic toxicity in a D. magna animal model. It was found that the ecotoxicity is more potent than what was previously assumed in regulatory assessments based on information provided by chemical industry. Notably, it was found that low concentrations of Roundup induce reproductive failure in D. magna (paper I). Laboratory analysis show systematic differences which characterize these products. Substantial ppm-levels of glyphosate residues were found to be systematically present in all tested samples of Roundup-ready soybean (paper II). Life-long feeding-study with soybean-feed in D. magna demonstrated that overall animal performance measured as growth and reproduction was significantly affected by soy-meal diets. Animals fed transgenic soybean-meal showed significantly reduced growth and reproduction (paper III). The research presented in papers II, II and IV contributes to a body of evidence indicating that directly and indirectly measurable material differences between transgenic and conventional cultivars are significant qualitative aspects, which challenge the concept of substantial equivalence. The traditional methodology for testing whether transgenic plants are substantially equivalent to their unmodified origins should be adjusted based on these findings. Finding that exposure to low-levels of glyphosate or Roundup in the environment will impair D. magna growth and reproduction, indicates that the negative effects seen in feeding-studies could be caused by toxic effects from glyphosate residues

In plastico: laboratory material newness affects growth and reproduction of Daphnia magna reared in 50-ml polypropylene tubes

Plastic laboratory materials are found to affect vital parameters of the waterflea Daphnia magna. The main responsible factor is defined as “newness” of the materials. Juvenile D. magna were raised individually in; a) new laboratory-standard 50 ml polypropylene tubes, and; b) identical tubes which had been washed and aerated for several weeks. Newness had significant effects on growth and fecundity of D. magna. New tubes caused delayed maturation, reduced reproduction and reduced growth when compared to washed and re-used tubes of the same commercial brand. The findings indicate that newness of tubes has inhibiting or toxic effects on D. magna. Often laboratory plastics are intended for single-use due to sterility demands. Newness might be an important confounding factor in research results and should not be disregarded. Disposable plastic utensils may come with a seemingly ignored cost and induce adverse effects in biological test-organisms and systems. The presented findings accentuate continued need for general awareness concerning confounding factors stemming from material laboratory environment. Based on the present findings the authors suggest that plastics intended for use in sensitive research may need to be washed and aerated prior to use

Silent Spring for Academic Dialogue: biotech industry leaves critique unopposed

publishedVersio

Silent Spring for Academic Dialogue: biotech industry leaves critique unopposed

publishedVersio

Life cycle fitness differences in Daphnia magna fed Roundup-Ready soybean or conventional soybean or organic soybean

A lifelong feeding study with soybean from different production systems was carried out in the crustacean Daphnia magna (water flea), an acknowledged model organism for ecotoxicological studies. Experimental diets were prepared with soybean meal from different agriculture production systems: (i) genetically modified Roundup‐Ready soy (Glyphosate‐Tolerant), (ii) conventional soy and (iii) soy from organic agriculture (agriculture with neither synthetic pesticides nor synthetic fertilizers). Overall, feed produced from organic soybeans resulted in the highest fitness (higher survival, better growth and fecundity) in the model organism. Animals fed Roundup‐Ready soybean consistently performed less well compared to animals fed either conventional or organic soybeans. We conclude that accumulation of herbicide residues in Roundup‐Ready soy and related nutritional differences between the soy types may have caused the observed fitness differences. The results accentuate the need for further research clarifying qualitative aspects, including potential large‐scale consequences for food and feed quality, of this dominant crop

Are ready for Market Genetically Modified, Conventional and Organic Soybeans Substantially Equivalent as Food and Feed?

Important compositional elements, including residues of herbicides, were investigated in commercial soy varieties grown within the same geographical area. These included genetically modified, conventional and organic soybeans. Feed made from these soybeans was subsequently fed to the model organism Daphnia magna, while measuring the fitness performance (survival, growth and reproduction) during the full life cycle of the animals. The conventional and organic samples contained no residues of glyphosate or its degradation product AMPA, but the GM-soy contained such residues, averaging 9.0 mg/kg. The fitness of D. magna fed organic soybeans was superior to that of animals fed GM soybeans, while animals fed conventional soybeans was intermediate. There were large fitness differences for D. magna fed raw soybeans, but smaller with heat-treated soy. In conclusion: herbicides associated with GM soybeans (and/or other factors associated with these crops) may compromise food and feed quality

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Accepted manuscript version. Published version at http://doi.org/10.1016/j.foodchem.2014.08.042. License in accordance with the journal's policy - CC-BY-NC-ND

Glyphosate-Residues in Roundup-Ready Soybean Impair Daphnia magna Life-Cycle

Herbicide tolerant plants such as Roundup-Ready soybean contain residues of glyphosate herbicide. These residues are considered safe and previous animal-feeding-studies have failed to find negative effects related to such chemical residues. The present study tests 8 experimental soy- meal diets as feed in groups (each containing 20 individuals) of test-animals (D. magna). The diets have different levels of glyphosate residues and we show that animal growth, reproductive maturity and number of offspring are correlated with these chemicals. The tested soybeans are from ordinary agriculture in Iowa USA and the residues are below the regulatory limits. Despite this, clear negative effects are seen in life-long feeding. The work enhances the need for including analysis of herbicide residues in future assessment of GMO