title: Effects of TiO2nanoparticles and sunscreens on coastal marine microalgae: Ultraviolet radiation is key variable for toxicity assessment.
abstract: Given the large numbers of sunbathers on beaches, sunscreen compounds are being released into the coastal aquatic environment in significant amounts. Until now the effect of these potential pollutants on microbiota has been not well-known. Phytoplankton is a key component of the microbiota community. It forms the basis of the aquatic trophic networks, and any change in the natural population of phytoplankton can affect the structure of aquatic biota. This paper describes an experiment performed outdoors (in natural sunlight conditions including ultraviolet radiation (UVR) and with UVR blocked) on mixed microalgae populations (four species from different key marine taxonomic groups, Nannochloropsis gaditana, Chaetoceros gracilis, Pleurochrysis roscoffensis and Amphidinium carterae), for three days, exposed to a range of concentrations of three commercial sunscreens (with variable TiO2concentrations: highest concentration for sunscreen C, followed by sunscreen A; and sunscreen B did not contain TiO2in its composition). With regard to UVR effect, in the absence of sunscreens, the most sensitive species is the centric diatom, Chaetoceros gracilis, and the least is Nannochloropsis gaditana; this last species presented the same behavior in the absence of UVR and with high sunscreen concentrations. The toxicity gradient obtained for sunscreens and nanoparticles under UVR is: TiO2NPs>Sunscreen C>Sunscreen A>Sunscreen B. The differential sensitivity of microalgae to sunscreens and TiO2NPs can produce a change in the dynamics of phytoplankton populations and provoke undesirable ecological effects (such as giving dinoflagellates more prominence). The effects of UVR, commonly neglected in bioassays, could alter the results in important ways and should be considered when performing environmentally-relevant bioassays. The toxicity mediated by hydrogen peroxide production associated with the concentration of TiO2NPs cannot be considered the only factor responsible for the toxicity: the organic compounds in the sunscreens must also be taken into account.
authors.affiliation: Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), Campus Río S. Pedro, 11510 Puerto Real, Cádiz, Spain. Electronic address: marta.sendra@icman.csic.es.
authors.forename: M
authors.initials: M
authors.lastname: Sendra
authors.affiliation: Department of Global Change Research, Mediterranean Institute of Advanced Studies (UIB-CSIC), Miguel Marqués, Esporles, Balearic Islands, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Sánchez-Quiles
authors.affiliation: Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), Campus Río S. Pedro, 11510 Puerto Real, Cádiz, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Blasco
authors.affiliation: Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), Campus Río S. Pedro, 11510 Puerto Real, Cádiz, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Moreno-Garrido
authors.affiliation: Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), Campus Río S. Pedro, 11510 Puerto Real, Cádiz, Spain.
authors.forename: L M
authors.initials: LM
authors.lastname: Lubián
authors.affiliation: Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), Campus Río S. Pedro, 11510 Puerto Real, Cádiz, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Pérez-García
authors.affiliation: Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), Campus Río S. Pedro, 11510 Puerto Real, Cádiz, Spain; Department of Global Change Research, Mediterranean Institute of Advanced Studies (UIB-CSIC), Miguel Marqués, Esporles, Balearic Islands, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Tovar-Sánchez
mesh_terms: D004141:Dinoflagellida / Q000187:drug effects*; D058086:Microalgae / Q000187:drug effects*; D053758:Nanoparticles / Q000528:radiation effects / Q000633:toxicity; D013473:Sunscreening Agents / Q000528:radiation effects / Q000633:toxicity; D014025:Titanium / Q000528:radiation effects / Q000633:toxicity; D014466:Ultraviolet Rays
chemical_list: D013473:Sunscreening Agents; C009495:titanium dioxide; D014025:Titanium
keywords: Marine phytoplankton; Peroxides; Population drift; Sunscreens; TiO(2) nanoparticles