Research Project: Quantitative Analysis of the Accumulation of Atrazine and its Metabolites in the Digestive Gland of Crayfish Prerequisite: Understanding of how to make dilutions, as well as an understanding of general Biology and Chemistry. Description: Atrazine is the most commonly used herbicide in the United States and is heavily applied to farm fields in the Midwestern region each year to control the growth of broad-leaf weeds. After atrazine has been applied to crops, it has a high susceptibility for leaching and run-off, especially after heavy rainfalls. High concentrations of atrazine (>80 ppb or μg/L) may ultimately enter nearby streams and rivers and remain high for several weeks, ultimately affecting aquatic organisms. Atrazine concentrations that are well over the “safe” concentration limit of 3 ppb set by the Environmental Protection Agency have routinely been reported. Our study will use crayfish to examine bioaccumulation of atrazine and its main metabolites (i.e., diaminochlorotriazine (DACT), deisopropylatrazine (DIP), and deethylatrazine (DE)) in the digestive gland (liver) and muscle tissue following exposures to environmentally relevant concentrations of atrazine.