engleski

Stability and toxicity of selected sun protective compounds in didinfection processes

The usage of different solar blocking personal care products to prevent the risk of skin cancer development is increasing constantly. These products contain various protective compounds, which are relatively stable when exposed to UV radiation. However, if they are used under certain special conditions, they might decompose by light or may react with the disinfection agents, such as those commonly present in pools. In the present research, selected benzophenones (BP-3, BP-4, DHHB) were applied as model compounds for the stability and toxicity studies of UV filters in presence of chlorine-based disinfectants such as NaOCl or trichloroisocyannuric acid (TCCA). The results showed that BP-3 and BP-4 react with NaOCl and TCCA, in both cases mainly two chlorinated products, 5-chloro and 3, 5-dichloro derivative, were identified. In the chlorination experiments of DHHB treated with the same reagents, we observed very fast reaction, leading to the formation of 3-chloro derivate of DHHB, as well as other at the moment unidentified products. Chlorinated products were determined by HPLC and compared with independently prepared standards. For identification of chlorinated products GC-MS and LC-MS were applied. Toxicity testing with luminescent bacteria V. fischeri was performed. Results revealed that DHHB caused 20% of inhibition in the luminescence of bacteria within 30 minutes of exposure and 30 min EC20 value was 0.96 mg L-1. In addition to V. fischeri toxicity testing, aqueous solutions of DHHB (as analytical standard or ‘in-house’ synthesized product) and its possible chlorinated derivatives (3-chloro and 5-chloro DHHB) were tested for possible adverse effects on microalgae Selenastrum capricornutum (Pseudokirchneriella subcapitata) and microcrustacean (Daphnia magna). Obtained data demonstrated that algae were more sensitive to DHHB than to its chlorinated products with an EC50 (72 h) for DHHB of 0.011 ppm (analytical standard) and 0.068 ppm (for 'in-house' synthesized). On contrary, D. magna was affected more by DHHB's chlorinated products, especially 3-chloro DHHB with a EC50 for 24 and 48 h of 0.89 and 0.38 ppm, respectively. In general, algae resulted more sensitive to DHHB-mediated action compared to tested microcrustacean. Potential estrogenicity and toxicity of BP3, BP4 and chlorinated BP3 product (5-chloro BP3) to different aquatic species from different taxonomic groups were studies. Toxic effects of UV filters were studied on bacteria Vibrio fischeri, algae Desmodesmus subspicatus, water fleas Daphnia magna and zebrafish Danio rerio. We found that UV filter BP3 was more toxic than BP4 ; the highest sensitivity was observed when water fleas Daphnia magna and algae Desmodesmus subspicatus were used as test organisms. BP4 revealed adverse effects on aquatic organisms only at concentrations of some tens milligrams per liter. The acute toxicity of chlorinated product (5-chloro BP3) did not increase significantly in comparison to BP3 ; increased toxicity was found only in a case of algae. The results of YES assay showed no estrogenic activity of both tested UV filters and chlorinated product.

benzophenones; BP-3; BP-4; DHHB; toxicity

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