Atrazine And Metalaxyl Are Toxic In Aquatic Environment

Aquatic toxicity refers to how certain compounds interact with organisms in marine ecosystems. Human activities such as agriculture often require the use various compounds; many of these compounds, however, flow into rivers, lakes, and other bodies of water via surface runoff. The compounds that we investigated in this experiment were atrazine (Figure 1), an herbicide that kills broadleaf and grassy weeds, and metalaxyl (Figure 2), a fungicide that kills oomycetes and water-mold fungi. Although compounds such as atrazine and metalaxyl are useful, they can be toxic in aquatic environments. The purpose of this experiment was to determine whether or not atrazine and metalaxyl are toxic in aquatic environments by comparing experimentally derived logKOW and

These techniques were used in the experiment to calculate atrazine and metalaxyl's logKOW and HOMO-LUMO ΔE values by creating calibration curves, calculating octanol-water partitions, and finding the EC50 (effective-concentration) of the ecotoxicity assay. Meanwhile, computational methods that were relevant to this experiment included HOMO-LUMO ΔE analyses on WebMO and referencing ChemSpider for predicted and literature logKOW values. It is important to note the controls that were used during this experiment; for the spectrophotometry, blank cuvettes and dark controls were used to ensure the accuracy of the absorbance and fluorescence data. Meanwhile, for the algae assay, the use of algae controls without pesticide provided a baseline for how much the algae grew without any pesticide. The species of algae (Pseudokirchneriella subcapitata) used and the conditions the algae were kept in (incubation and freezing) were universal for all ecotoxicity