title: Effect of 2,4-dihydroxybenzophenone (BP1) on early life-stage development of the marine copepod Acartia tonsa at different temperatures and salinities.
abstract: Benzophenone (BP)-type ultraviolet (UV) filters are widely used in cosmetic and sunscreen products and can enter the aquatic environment. Therefore, we investigated the subchronic toxicity of 2,4-dihydroxybenzophenone (BP1) on the marine calanoid copepod Acartia tonsa in an early life-stage development study. Since developmental endpoints depend on environmental conditions, a preceding study of A. tonsa development was performed at three temperatures, four salinities, four light:dark regimes, six food densities, and four culture densities. Times elapsed until 50% of the population had reached a copepodite stage (DT(½) ) at the different conditions were calculated. The DT(½) values decreased from 296 h at 15°C to 89 h at 25°C and were also affected by salinity (126 h at 15‰ and 167 h at 30‰), whereas the light:dark regime and culture density influenced development only to a minor extent. BP1 was found acutely toxic at 2.6 mg/L (48-h median lethal concentration [LC50]). The toxicity of BP1 on early life-stage development was studied in combinations of three temperatures (15, 20, 25°C) and three salinities (15, 20, 25‰) using five toxicant concentrations between 0.051 and 2 mg/L in each scenario. Concentrations causing 10 and 50% inhibition of development (EC10 and EC50) were determined. Acartia tonsa was most resistant towards BP1 at 20°C where an EC50 of 1.1 mg/L was found, whereas EC50 values were significantly lower at 15°C (0.49 mg/L) and 25°C (0.77 mg/L), respectively. The EC50 also decreased with increasing salinity. Our results demonstrate that environmental conditions do influence toxicity test results; thus, they need to be considered carefully when developing test protocols as well as for environmental risk assessments of chemicals.
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark. koku@env.dtu.dk
authors.forename: Kresten Ole
authors.initials: KO
authors.lastname: Kusk
authors.forename: Manola
authors.initials: M
authors.lastname: Avdolli
authors.forename: Leah
authors.initials: L
authors.lastname: Wollenberger
mesh_terms: D000818:Animals; D001577:Benzophenones / Q000633:toxicity*; D033342:Copepoda / Q000187:drug effects* / Q000254:growth & development; D008018:Life Cycle Stages / Q000187:drug effects; D054712:Salinity; D012623:Seawater / Q000737:chemistry*; D013473:Sunscreening Agents / Q000633:toxicity; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D001577:Benzophenones; D013473:Sunscreening Agents; D014874:Water Pollutants, Chemical; C121479:2,4-dihydroxybenzophenone