Nanosized titanium dioxide UV filter increases mixture toxicity when combined with parabens

• Published in: Ecotoxicology and environmental safety 2019-11, Vol.184, p.109565, Article 109565
• Main Authors: Soler de la Vega, Ana C., Molins-Delgado, Daniel, Barceló, Damià, Díaz-Cruz, M. Silvia
• Format: Article
• Language: English
• Subjects: Aquatic Organisms - drug effects; Drug Interactions; Joint toxicity; Metal oxide nanoparticles; Nanomaterials; Parabens - toxicity; Particle Size; Personal care products; Titanium - chemistry; Titanium - toxicity; UV filters; Water Pollutants, Chemical - toxicity
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2019.109565

To address the concern about the environmental impact of engineered nanoparticles frequently used in the recently marketed personal care and hygiene products (PCPs), we conducted a toxicity assessment and determined the EC50 values of the nanosized inorganic UV filter TiO2 (nano-TiO2), as well as those of the organic UV filter oxybenzone (BP3) and three parabens (methyl, propyl, and benzylparaben) present in most PCPs formulation. The bioassays were carried out through standardized toxicity bioassays on two environmentally relevant aquatic species i.e. Daphnia magna and Phaeodactylum tricornutum. For nano-TiO2 48 h EC50 on D. magna was 3.09 mgL−1 and for parabens ranged from 32.52 to 1.35 mgL−1. The two most toxic compounds on D. magna, nano-TiO2 and benzylparaben (BzP), were further tested with the algae. For nano-TiO2 72 h EC50 value was 2.27 mgL−1 and for BzP it was 10.61 mgL−1. In addition, D. magna was exposed to selected binary mixtures of the target compounds i.e. nano-TiO2+BP3, nano-TiO2+BzP and BP3+BzP On the endpoint of 48 h, a synergistic action was observed for nano-TiO2+BP3 and nano-TiO2+BzP, but an antagonistic effect occurred in the mixture BP3+BzP. These findings suggest that nano-TiO2 can increase the toxicity of the mixture when combined with other compounds. •Estimated EC50for nano-TiO2and MeP, PrP, and BzP toward aquatic organisms were in the mgl-1range.•Nano-TiO2 and BzP showed the highest toxicity.•Nano-TiO2added to BP3 and to BzP, provoked synergistic toxic effects.•An antagonistic action was observed for the mixture BP3+BzP.