title: Copper toxicity and the influence of water quality of Dongnai River and Mekong River waters on copper bioavailability and toxicity to three tropical species.
abstract: The present study investigated copper (Cu) toxicity and the influence of water quality characteristics of Dongnai River and Mekong River (Vietnam) surface waters to three tropical species; Daphnia lumholtzi, Ceriodaphnia cornuta, and Danio rerio. The river waters had a range of water quality parameters that modify Cu bioavailability and toxicity. The range of total hardness, alkalinity, pH and dissolved organic carbon were 15-64 mg/L as CaCO3, 18-58 mg/L as CaCO3, 6.62-7.88, and 6.9-14.7 mg/l, respectively. The US EPA acute toxicity test method with a modification to the light photoperiod and temperature for tropical organisms was used to investigate Cu toxicity. Result of the present study found that Cu produced toxic effect to the studied organisms at low concentrations. The 48-h LC50 ranged from 3.92 to 8.61 µg/l, 2.92-9.56 µg/l, and 15.71-68.69 µg/l dissolved Cu for D. lumholtzi, C. cornuta, and D. rerio, respectively. In general, water quality had an influence on Cu bioavailability and toxicity to the studied organisms. The toxicity of Cu was higher in water with lower hardness, DOC, and/or pH. The present study indicates a contribution of Cu hydroxide and carbonate to Cu bioavailability to Mekong organisms. Results of the present study will be used for calibrating the US Cu Biotic Ligand Model (BLM) to Mekong River water and organisms in support of application of the BLM for setting site-specific Cu water quality guidelines in the ecosystem of the Lower Mekong River Basin.
authors.affiliation: Institute for Environment and Resources, Vietnam National University - Hochiminh City, 142 To Hien Thanh St., Dist. 10, Hochiminh City, Viet Nam. Electronic address: bltkhiet@vnuhcm.edu.vn.
authors.forename: Thanh-Khiet L
authors.initials: TK
authors.lastname: Bui
authors.affiliation: Institute for Environment and Resources, Vietnam National University - Hochiminh City, 142 To Hien Thanh St., Dist. 10, Hochiminh City, Viet Nam; Vietnam National University - Hochiminh City, Linhtrung Ward, Thuduc Dist., Hochiminh City, Viet Nam.
authors.forename: L Chi
authors.initials: LC
authors.lastname: Do-Hong
authors.affiliation: Hochiminh City University of Technology, Vietnam National University - Hochiminh City, 268 Ly Thuong Kiet St., Dist. 10, Hochiminh City, Viet Nam.
authors.forename: Thanh-Son
authors.initials: TS
authors.lastname: Dao
authors.affiliation: Institute of Environmental Sustainability, Loyola University Chicago, 1032 W. Sheridan Road, Chicago, IL, USA.
authors.forename: Tham C
authors.initials: TC
authors.lastname: Hoang
mesh_terms: D000818:Animals; D001682:Biological Availability; D002119:Calcium Carbonate / Q000737:chemistry; D003300:Copper / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity*; D003621:Daphnia / Q000187:drug effects / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods*; D008024:Ligands; D008962:Models, Theoretical; D045483:Rivers / Q000737:chemistry*; D023382:Toxicity Tests, Acute; D014744:Vietnam; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity*; D060753:Water Quality; D015027:Zebrafish / Q000254:growth & development / Q000378:metabolism
chemical_list: D008024:Ligands; D014874:Water Pollutants, Chemical; D003300:Copper; D002119:Calcium Carbonate
keywords: Ceriodaphnia cornuta; Copper bioavailability; Copper toxicity; Cu-BLM; Danio rerio; Daphnia lumholtzi; Mekong river organism