title: Single- and mixture toxicity of three organic UV-filters, ethylhexyl methoxycinnamate, octocrylene, and avobenzone on Daphnia magna.
abstract: In freshwater environments, aquatic organisms are generally exposed to mixtures of various chemical substances. In this study, we tested the toxicity of three organic UV-filters (ethylhexyl methoxycinnamate, octocrylene, and avobenzone) to Daphnia magna in order to evaluate the combined toxicity of these substances when in they occur in a mixture. The values of effective concentrations (ECx) for each UV-filter were calculated by concentration-response curves; concentration-combinations of three different UV-filters in a mixture were determined by the fraction of components based on EC25values predicted by concentration addition (CA) model. The interaction between the UV-filters were also assessed by model deviation ratio (MDR) using observed and predicted toxicity values obtained from mixture-exposure tests and CA model. The results from this study indicated that observed ECxmix(e.g., EC10mix, EC25mix, or EC50mix) values obtained from mixture-exposure tests were higher than predicted ECxmix(e.g., EC10mix, EC25mix, or EC50mix) values calculated by CA model. MDR values were also less than a factor of 1.0 in a mixtures of three different UV-filters. Based on these results, we suggest for the first time a reduction of toxic effects in the mixtures of three UV-filters, caused by antagonistic action of the components. Our findings from this study will provide important information for hazard or risk assessment of organic UV-filters, when they existed together in the aquatic environment. To better understand the mixture toxicity and the interaction of components in a mixture, further studies for various combinations of mixture components are also required.
authors.affiliation: Environmental Safety Group, Korea Institute of Science and Technology (KIST) Europe, 66123 Saarbrücken, Germany.
authors.forename: Chang-Beom
authors.initials: CB
authors.lastname: Park
authors.affiliation: Environmental Safety Group, Korea Institute of Science and Technology (KIST) Europe, 66123 Saarbrücken, Germany.
authors.forename: Jiyi
authors.initials: J
authors.lastname: Jang
authors.affiliation: Environmental Safety Group, Korea Institute of Science and Technology (KIST) Europe, 66123 Saarbrücken, Germany.
authors.forename: Sanghun
authors.initials: S
authors.lastname: Kim
authors.affiliation: Environmental Safety Group, Korea Institute of Science and Technology (KIST) Europe, 66123 Saarbrücken, Germany. Electronic address: youngjunkim@kist-europe.de.
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Kim
mesh_terms: D000179:Acrylates / Q000633:toxicity*; D000818:Animals; D059001:Aquatic Organisms / Q000187:drug effects; D002934:Cinnamates / Q000633:toxicity*; D003621:Daphnia / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D011427:Propiophenones / Q000633:toxicity*; D013473:Sunscreening Agents / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000179:Acrylates; D002934:Cinnamates; D011427:Propiophenones; D013473:Sunscreening Agents; D014874:Water Pollutants, Chemical; C516303:ethylhexyl methoxycinnamate; C088673:octocrylene; C049935:avobenzone
keywords: Antagonistic effect; Concentration addition; Daphnia magna; Mixture toxicity; Organic UV-filters