OBSERVING THE EFFECTS OF ROUNDUP EXPOSURE ON THE ACTIVITY LEVELS OF C. ELEGANS

Monsanto Company claims that its herbicide, Roundup®, is safe to animals because its active ingredient, glyphosate, only affects the shikimic acid pathway, which is not present in animals. According to Monsanto, Roundup® should pose no health risks to humans. However, recent studies have linked glyphosate to a variety of diseases in humans and the International Agency for Research on Cancer has recently (2016) classified glyphosate as “probably carcinogenic to humans.” Industry studies designed to test the effects of glyphosate alone have not studied the effects of the entire herbicide preparation that is widely used in the field. Given that the effects of the entire chemical makeup of Roundup®, including surfactants, are not well understood, the goal of this investigation is to determine whether exposure to the herbicide Roundup® adversely affects the health of the nematode Caenorhabditis elegans, which, like humans, lacks a shikimic acid pathway. C. elegans, at various stages of development, were exposed to dilutions of Roundup® Weed & Grass Killer Super Concentrate containing 0.25% - 5.0% glyphosate. The activity of individual nematodes was monitored using a 0-3 activity level scale. Exposure to Roundup® resulted in decreased activity or death in a dose-response pattern. These effects were observed at concentrations as low as 0.25% glyphosate, which is ¼ the recommended usage concentration of the herbicide. The nematodes were separated into “mature” (L4 and adult) and “immature” (L1-L3) groups. Compared to mature worms, immature C.elegans exposed to Roundup® containing higher concentrations of glyphosate (2.5% - 5.0%) were found to be more susceptible, resulting, on average, in at least a two-fold decrease in activity level by the end of the observation period (7 hours). In addition to a large decrease in activity levels, greater morbidity was observed. Despite the industry’s claims of the lack of negative influence of Roundup® on organisms other than on target plant species, these results suggest toxicity and support a need for further investigation on the impact of glyphosate on organisms lacking a shikimic acid pathway.