title: Toxicity of cadmium-contaminated clay to the zebrafish Danio rerio.
abstract: In this study, the toxicity of cadmium-contaminated clay to the zebrafish Danio rerio was evaluated. Kaolin clay was spiked with CdCl(2) (1.28 mg Cd/g clay) and adult zebrafish were exposed to 0, 500, 1,000, and 2,000 mg/L Cd-contaminated clay in a continuous recirculation system. Cumulative mortality was evaluated as a function of exposure time, and LT50 values were calculated. Results of acute toxicity tests showed that an exposure to 1,000 mg/L Cd-contaminated clay resulted in LT50 values of 12 and 92 h (n = 2 experiments) and in a LT50 value of 22 h in both experiments with 2,000 mg/L Cd-contaminated clay. Positive control experiments with corresponding measured dissolved Cd concentrations were performed to evaluate by comparison the toxicity of the clay-bound Cd. These control experiments gave LT50 values higher than 144 h for both conditions. Moreover, no toxicity (LT50 > 144 h) of 2,000 mg/L uncontaminated clay was observed. This study showed that cadmium present on clay particles can be bioavailable and exert a toxic effect to the zebrafish D. rerio.
authors.affiliation: Department of Biology, University of Antwerp, Antwerp, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Van den Belt
authors.forename: S
authors.initials: S
authors.lastname: Van Puymbroeck
authors.forename: H
authors.initials: H
authors.lastname: Witters
mesh_terms: D000538:Aluminum Silicates / Q000633:toxicity*; D000818:Animals; D001682:Biological Availability; D002104:Cadmium / Q000493:pharmacokinetics / Q000633:toxicity*; D000077215:Clay; D017753:Ecosystem; D007616:Kaolin / Q000633:toxicity; D007928:Lethal Dose 50; D015027:Zebrafish
chemical_list: D000538:Aluminum Silicates; D002104:Cadmium; D007616:Kaolin; D000077215:Clay