title: Extended biotic ligand model for prediction of mixture toxicity of Cd and Pb using single metal toxicity data.
abstract: The combined toxic effects of Cd and Pb in the presence of different concentrations of Ca(2+) were predicted using the biotic ligand model (BLM), with the parameters derived from the Cd-only and Pb-only toxicity data. The BLM-based toxic unit (TU) approach and the proposed BLM-based f(mix) approach were used for prediction. The predicted mixture toxic effects using the BLM-based f(mix) approach were closer to the observed mixture effects (root mean square error [RMSE] = 9.7 at 25 mM Ca(2+) ) than that using the BLM-based TU approach (RMSE = 25.6 at 25 mM Ca(2+) ). This can be attributed to the fact that the BLM-based TU approach only considers the competition between Ca(2+) and Cd or Pb, whereas the BLM-based f(mix) approach considers both the competition between Cd and Pb and the competition between Ca(2+) and Cd or Pb for biotic ligand sites. In addition, the parameters derived from the Cd-only and Pb-only solutions in the presence of the background Ca(2+) concentration (0.025 mM) could be used to predict the mixture toxic effects at higher Ca(2+) concentrations. The BLM-based f(mix) approach proposed in the current study suggests a new way of predicting the Cd-Pb mixture toxicity from the single metal toxicity data by adopting the f(mix) values.
authors.affiliation: Department of Civil and Environmental Engineering, Seoul National University, Gwanakgu, Seoul, Republic of Korea.
authors.forename: Eun Hea
authors.initials: EH
authors.lastname: Jho
authors.forename: Jinsung
authors.initials: J
authors.lastname: An
authors.forename: Kyoungphile
authors.initials: K
authors.lastname: Nam
mesh_terms: D048908:Aliivibrio fischeri / Q000187:drug effects; D002104:Cadmium / Q000737:chemistry / Q000633:toxicity*; D002118:Calcium / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D017753:Ecosystem; D007854:Lead / Q000737:chemistry / Q000633:toxicity*; D008024:Ligands; D008954:Models, Biological; D008956:Models, Chemical; D018675:Toxicity Tests / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D008024:Ligands; D014874:Water Pollutants, Chemical; D002104:Cadmium; D007854:Lead; D002118:Calcium