Friday, February 17, 2017
Exhibit Hall (Hynes Convention Center)
Fiona Sweeney, St. Johnsbury Academy, St. Johnsbury, VT
Johannes Testorf, Hanover High School, Hanover, NH
Glyphosate is an herbicide commonly used as the active ingredient in agricultural products such as Roundup™. The EPA states that glyphosate has a low acute toxicity on humans and wildlife. Contrary to this, outside studies have shown both acute and chronic negative effects of glyphosate on animals. Our studies were performed on the species D. magna and C. elegans to investigate the acute toxicological effects of glyphosate in Roundup. We prepared glyphosate dilutions between 10% and 0.01% from a Roundup solution that contains 50% glyphosate, and applied them to our specimens for periods ranging from 0 to 300 minutes. Results for D. magna showed a statistically significant effect where specimens placed in higher concentrations of glyphosate died faster than those at lower concentrations. These times ranged from an average of 9 minutes for specimens placed in a 10% glyphosate solution to an average of 71 minutes for specimens placed in a 0.01% glyphosate solution. The controls outlived the time during which the specimens were observed. Experiments involving C. elegans did not show such clear results. More concentrated solutions tended to lead to higher rates of death, but this effect was not consistent in all of our experiments. The standard error in survival times was on average less than 10%, with the highest margins going up to 40%. This was likely due to difficulties accurately counting the worms through visual means under a microscope. We will continue to repeat our experiments on C. elegans in order to find a more definitive pattern. Additional research will be performed to test how our methods apply to our test species at different stages of growth, and whether our results can be generalized to other animals.