title: Acute and chronic toxicity of atrazine and its metabolites deethylatrazine and deisopropylatrazine on aquatic organisms.
abstract: Little is known about the toxicity of the atrazine (ATRZ) metabolites desethylatrazine (DEA) and deisopropylatrazine (DIA). We evaluated the acute and chronic toxicity of ATRZ, DEA, and DIA on the amphipods Hyalella azteca and Diporeia spp., and the unicellular algae Pseudokirchneriella subcapitata. In general, acute and chronic toxicity was ranked ATRZ > DEA > DIA. All 96-h median inhibition concentrations (IC(50)) were above concentrations found in the environment (>1,500 microg/L), and sensitivity was highest for the algae. When amphipods were exposed chronically (21 days), Diporeia was several orders of magnitude more sensitive compared to H. azteca. Neither ATRZ nor DEA altered H. azteca sex ratios. In conclusion, our results suggest that short-term exposures of these chemicals to algae and amphipods to concentrations routinely detected in surface waters are unlikely to be a cause of concern. However, the unexpected high sensitivity of Diporeia spp. to these herbicides deserves further attention considering the declining status of this amphipod in the Great Lakes basin.
authors.affiliation: Department of Forestry and Natural Resources, Purdue University, 195 Marsteller St., West Lafayette, IN, 47907, USA.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Ralston-Hooper
authors.forename: Jeff
authors.initials: J
authors.lastname: Hardy
authors.forename: Leighanne
authors.initials: L
authors.lastname: Hahn
authors.forename: Hugo
authors.initials: H
authors.lastname: Ochoa-Acuña
authors.forename: Linda S
authors.initials: LS
authors.lastname: Lee
authors.forename: Robert
authors.initials: R
authors.lastname: Mollenhauer
authors.forename: Maria S
authors.initials: MS
authors.lastname: Sepúlveda
mesh_terms: D033304:Amphipoda / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D001280:Atrazine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000633:toxicity*; D000460:Chlorophyta / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006540:Herbicides / Q000633:toxicity*; D008136:Longevity / Q000187:drug effects; D008297:Male; D012744:Sex Ratio; D018675:Toxicity Tests; D014227:Triazines / Q000633:toxicity
chemical_list: C445502:6-chloro-N-ethyl-1,3-5-triazine-2,4-diamine; D006540:Herbicides; D014227:Triazines; C446541:deethylatrazine; D001280:Atrazine