title: Probabilistic risk assessment of diuron and prometryn in the Gwydir River catchment, Australia, with the input of a novel bioassay based on algal growth.
abstract: A probabilistic risk assessment of the selected herbicides (diuron and prometryn) in the Gwydir River catchment was conducted, with the input of the EC₅₀ values derived from both literature and a novel bioassay. Laboratory test based on growth of algae exposed to herbicides assayed with a microplate reader was used to examine the toxicity of diuron and prometryn on the growth of Chlorella vulgaris. Both herbicides showed concentration dependent toxicity in inhibiting the growth of Chlorella during the exposure period of 18-72 h. Diuron caused more toxicity as judged by growth rates than prometryn. Thalaba Creek at Merrywinebone was identified as the 'hotspot' for diuron and prometryn risk in the Gwydir catchment. The use of microplate assays coupled with probabilistic risk assessment is recommended for rapid assessment of ecotoxicity of indigenous species, allowing identification of locations in river catchments requiring environmental management.
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: yajuanshi@rcees.ac.cn.
authors.forename: Yajuan
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Faculty of Agriculture and Environment, University of Sydney, NSW 2000, Australia; Prince of Songkla University-Phuket, Kathu, Phuket 83120, Thailand.
authors.forename: Mitchell
authors.initials: M
authors.lastname: Burns
authors.affiliation: Prince of Songkla University-Phuket, Kathu, Phuket 83120, Thailand.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Ritchie
authors.affiliation: Faculty of Agriculture and Environment, University of Sydney, NSW 2000, Australia.
authors.forename: Angus
authors.initials: A
authors.lastname: Crossan
authors.affiliation: Faculty of Agriculture and Environment, University of Sydney, NSW 2000, Australia.
authors.forename: Ivan R
authors.initials: IR
authors.lastname: Kennedy
mesh_terms: D001315:Australia; D001681:Biological Assay; D048408:Chlorella vulgaris / Q000187:drug effects* / Q000254:growth & development; D004237:Diuron / Q000032:analysis / Q000633:toxicity; D054750:Ecotoxicology; D011400:Prometryne / Q000032:analysis / Q000633:toxicity; D018570:Risk Assessment; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D011400:Prometryne; D004237:Diuron
keywords: Database study; Eco-toxicity; Probabilistic risk assessment; Toxicity bioassay