title: Examining the joint toxicity of chlorpyrifos and atrazine in the aquatic species: Lepomis macrochirus, Pimephales promelas and Chironomus tentans.
abstract: The joint toxicity of chlorpyrifos and atrazine was compared to that of chlorpyrifos alone to discern any greater than additive response using both acute toxicity testing and whole-body residue analysis. In addition, acetylcholinesterase (AChE) inhibition and biotransformation were investigated to evaluate the toxic mode of action of chlorpyrifos in the presence of atrazine. The joint toxicity of atrazine and chlorpyrifos exhibited no significant difference in Lepomis macrochirus compared to chlorpyrifos alone; while studies performed with Pimephales promelas and Chironomus tentans, did show significant differences. AChE activity and biotransformation showed no significant differences between the joint toxicity of atrazine and chlorpyrifos and that of chlorpyrifos alone. From the data collected, the combination of atrazine and chlorpyrifos pose little additional risk than that of chlorpyrifos alone to the tested fish species.
authors.affiliation: Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University at Carbondale, Carbondale, IL 62901-6511, USA.
authors.forename: W
authors.initials: W
authors.lastname: Tyler Mehler
authors.forename: Lance J
authors.initials: LJ
authors.lastname: Schuler
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lydy
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D001280:Atrazine / Q000633:toxicity*; D001711:Biotransformation; D002683:Chironomidae / Q000378:metabolism; D004390:Chlorpyrifos / Q000633:toxicity*; D002800:Cholinesterase Inhibitors / Q000633:toxicity; D003530:Cyprinidae / Q000378:metabolism; D004350:Drug Residues; D004357:Drug Synergism; D004784:Environmental Monitoring / Q000379:methods; D006540:Herbicides / Q000633:toxicity*; D007087:Illinois; D007306:Insecticides / Q000633:toxicity*; D007928:Lethal Dose 50; D009141:Musculoskeletal System / Q000187:drug effects; D010473:Perciformes / Q000378:metabolism; D023382:Toxicity Tests, Acute; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D002800:Cholinesterase Inhibitors; D006540:Herbicides; D007306:Insecticides; D014874:Water Pollutants, Chemical; D000110:Acetylcholinesterase; D004390:Chlorpyrifos; D001280:Atrazine