Izdelava ekotoksikološkega profila izbranih UV filtrov in silico

Tavčar, Klara (author), Jakopin, Žiga (mentor)

Anorganski in organski UV filtri so pogosta sestavina kozmetičnih izdelkov za zaščito pred soncem, saj so sposobni zaščititi kožo pred ultravijolično svetlobo s pomočjo absorpcije,odbijanja ali razprševanja žarkov. UV filtri niso popolnoma varni, saj se predvsem organskim UV filtrom poleg endokrinega delovanja pogosto pripisuje tudi ekotoksičnost za vodno okolje. Kot posledica ozaveščanja ljudi o uporabi zaščitnih izdelkov pred soncem pa jim je slednje vedno bolj izpostavljeno. V magistrski nalogi smo s pomočjo orodij in silico izdelali ekotoksikološki profil za pet organskih UV filtrov, ki so jih pogosto zaznali v naravi; benzofenon-3, etilheksilmetoksi cinamat, oktokrilen, avobenzon ter 4-metilbenziliden kafra. Z računalniškimi modeli smo ocenili njihovo stopnjo biorazgradljivosti, sposobnost bioakumulacije, zadrževanja v sedimentu in napovedali vrednosti LC50 za različne vodne organizme, nato pa smo ocenjene vrednosti primerjali z literaturnimi podatki in podatkovno bazo Ecotox. Napovedi so pokazale, da vrednoteni UV filtri niso sposobni biorazgradnje, njihove hidrofobne lastnosti pa nakazujejo na pretežno zadrževanje v sedimentu in vodnem dnu ter na sposobnost bioakumulacije v tkivih vodnih organizmov z možnostjo biomagnifikacije. Tudi napovedi vrednosti LC50 nakazujejo na obratno linearno korelacijo med srednjo letalno koncentracijo ter hidrofobnostjo spojine – bolj kot je spojina hidrofobna, nižja je vrednost LC50. Po primerjavi napovedi z literaturnimi viri in podatkovnimi bazami smo prišli do zaključka, da preučevani UV filtri glede na svoje fizikalno-kemijske lastnosti predstavljajo nevarnost za vodno okolje, zato določene države in območja s svojo regulativo že prepovedujejo uporabo večine izmed preiskovanih UV filtrov. Splošne metode za vrednotenje toksičnosti UV filtrov se ne osredotočajo na potencialno ekotoksičnost, zato bi jih bilo v prihodnosti smiselno izpopolniti in točno definirati kriterije za njihovo nevarnost okolju z določitvijo poenotene ocene tveganja, na podlagi katere bi se lahko med drugim oblikovali mednarodni certifikati za okolju prijazne izdelke za zaščito pred soncem.

• Language: Slovenian
• Keywords: UV filtri, ekotoksikološki profil, metode in silico, vodni ekosistem
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2022
• PID: 20.500.12556/RUL-142911
• Publication date in RUL: 02.12.2022

Secondary language

• Language: English
• Title: In silico ecotoxicological profiling of selected UV filters

Abstract

Anorganic and organic UV filters are one of the main ingredients in sunscreens due to their abillity of protection against ultraviolet light by absorbing, reflecting or scattering the rays. UV filters exhibit toxic potential, in particular organic UV filters, which are known endocrine disruptors, but often also exert toxicity to the aquatic environment. The increasing exposure is a direct result of the awareness-raising about the use of sunscreen products. In this thesis, we have used in silico tools to generate an ecotoxicological profile for five organic UV filters that are among the most common in the environment; benzophenone-3, ethylhexylmethoxycinnamate, octocrylene, avobenzone and 4-methylbenzylidene camphor. Computer models were used to estimate their biodegradability, bioaccumulation, sediment persistency and to predict LC50 values for different aquatic organisms. The estimated values were then compared with literature data and the Ecotox database. The predictions showed that the evaluated UV filters are not easily biodegradable and their hydrophobic properties indicate persistancy in sediment rather than in the aqueous phase. In addition, the predictions showed the ability of UV filters to bioaccumulate in the tissues of aquatic organisms, with potential for biomagnification. The LC50 predictions also suggest an inverse linear correlation between the mean lethal concentration value and the hydrophobicity of the compound – the more hydrophobic the compound, the lower its LC50. After comparing the predictions with databases and literature sources, we can conclude that the studied UV filters pose a risk to the aquatic environment due to their physicochemical properties, which incidentally led to the ban of particular UV filters in some countries. Common methods for evaluating toxicity are often not able to reveal potential ecotoxicity of UV filters. Therefore, in the future it would be useful if standardised analytical methods for evaluating the toxicity of UV filters and harmonized risk assessment were developed, which could facilitate development of international certificates for environmentally friendly sunscreen products.

• Keywords: UV filters, environmental toxicity, in silico methodology, aquatic environment