Toxicity to Daphnia magna, Hyalella azteca, Oncorhynchus kisutch, Oncorhynchus mykiss, Oncorhynchus tshawytscha, and Rana catesbeiana of Atrazine, Metolachlor, Simazine, and Their Formulated Products

Atrazine, metolachlord and simazine are herbicide active ingredients used for the aelective control of broadleaf weeds and grasses in field, nursery, and tree fruit crops. A manufaturer of atrazine is the Drexel Chemical Company (Memphis, TN, USA); and likewise metolachlor and simazine are produced by Syngenta Crop protection Canada, Inc. (Guelph, ON, Canada).