title: The effect of humic acid on the toxicity and bioavailability of trivalent chromium.
abstract: The influence of humic acid (HA) on the toxicity and bioavailability of two forms of trivalent chromium (chromic chloride and chrome lignosulfonate) was evaluated using a common freshwater invertebrate, Daphnia pulex. With both compounds, the 50 mg/liter HA significantly decreased toxicity at all time points examined. The remaining two HA concentrations, 0.5 and 5 mg/liter, either had no influence or decreased the toxicity of the compounds. Humic acid appeared to have no influence on the bioavailability of chrome lignosulfonate. However, for chromic chloride, 5 and 50 mg/liter HA decreased the percentage free chromium at all time points examined.
authors.affiliation: Toxicology Program, College of Pharmacy and Health Sciences, Northeast Louisiana University, Monroe 71209-0470.
authors.forename: R A
authors.initials: RA
authors.lastname: Stackhouse
authors.forename: W H
authors.initials: WH
authors.lastname: Benson
mesh_terms: D000818:Animals; D001682:Biological Availability; D002712:Chlorides; D002857:Chromium / Q000493:pharmacokinetics / Q000633:toxicity*; D017608:Chromium Compounds; D003621:Daphnia / Q000502:physiology; D006812:Humic Substances / Q000633:toxicity*; D007928:Lethal Dose 50; D013997:Time Factors
chemical_list: D002712:Chlorides; D017608:Chromium Compounds; D006812:Humic Substances; D002857:Chromium; C017133:chromous chloride