A larval medaka (Oryzias latipes) acute toxicity assay combined with solid-phase extraction to efficiently determine the toxicity of organic contaminants in river water

• Published in: Water science and technology Vol. 53; no. 11; pp. 213 - 219
• Main Authors: Liu, R, Kameya, T, Sugimura, Y, Sawai, A, Shigeoka, T, Urano, K
• Format: Journal Article
• Language: English
• Published: England IWA Publishing 01.01.2006
• Subjects: Acute toxicity; Animals; Biological Assay; Cartridges; Contaminants; Dissolved organic carbon; Dose-Response Relationship, Drug; Embryo, Nonmammalian - drug effects; Environmental Monitoring - methods; Extraction; Fish; Freshwater; Freshwater fishes; Industrial Waste; Lethal effects; Lethal limits; Methods; Organic contaminants; Oryzias - embryology; Oryzias latipes; Profiles; River water; Rivers; Time Factors; Toxicants; Toxicity; Toxicity testing; Toxicity Tests; Waste Disposal, Fluid - methods; Water analysis; Water Pollutants, Chemical - toxicity; Water pollution; Water quality; Water sampling
• ISBN: 9781843395713; 1843395711
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2006.355

Using a larval medaka (Oryzias latipes) acute toxicity assay combined with solid-phase extraction, we proposed a method for efficiently determining the fish toxicity of organic contaminants in river water. Organic toxicants were 10, 20, 50 and 100-fold concentrated from 4 L of the sample with adsorption cartridges. The lethal effect was observed by exposing every ten individuals of 48-72 h old larval medaka to 20 mL of each solution for 48h. The median lethal concentration rate (LCR50) was used as an indicator for the toxicity. With the developed toxicity test method, more than seven times difference was found in the LCR50 of the river water samples. LCR50 distribution profiles were compared with 125 samples in two typical rivers. The result revealed a lower toxicity level in the mainstream than in the confluences, and a lower toxicity level in Sagami River than in Ayase River. LCR50 proved unique as a toxicity indicator, which was impossible to speculate from the conventional water quality indicator of the dissolved organic carbon concentration. As an effective screening test for priority settings, the method can help us with an efficient planning for the environmental investigation and management.