TOXICITY AND HAZARD RANKING OF S-TRIAZINE HERBICIDES USING MICROTOX(R), 2 GREEN ALGAL SPECIES AND A MARINE CRUSTACEAN

The acute toxicities of five s-triazines (atrazine, prometryn, simetry n, ametryn, terbutryn) were measured using two algae (one freshwater s pecies, Selenastrum capricornutum, and one marine species, Dunaliella tertiolecta), Microtox(R) bacteria, and the brine shrimp, Artemia sali na. The algae were one to three orders of magnitude more susceptible t o tested compounds than were bacteria or brine shrimp. The transformat ion of effective concentrations of the chemicals, obtained from toxici ty measurements, into percent of the saturation level in water is prop osed as a first evaluation of potential hazard to aquatic systems. Sim etryn was found to be the most hazardous s-triazine for all species te sted.