Samenvatting

Coastal tourism and recreation are one of the most rapidly growing fields worldwide and people spend more time outdoors. Skin protection is, in this respect, important to prevent severe skin damage and skin aging. The past decades the awareness and the importance of skin protection against long time exposure to UVR increased. And therefore different types of sunscreen products are available on the market, among which are eco-friendly sunscreen products. The aim of this thesis is to provide a scientific contribution to the knowledge of sunscreen products, by investigating the effects of eco-friendly sunscreen products for the marine environment. The main question is “Can eco-friendly sunscreen products have adverse effects on the marine environment?”
To answer this question 3 approaches were selected. A literature research was performed to investigate which eco-friendly sunscreen products are available, including their claims. And to investigate the individual toxicity of all the UV filters used in these products, toxicity databases were made. Most eco-friendly sunscreen products contain non-nano ZnO as UV filter, but other mineral based UV filters and organic UV filters are also used in some cases. Furthermore the toxicity data showed that both nano and non-nano ZnO showed the strongest toxicity effects similar to the organic UV filters oxybenzone and octocrylene. Whereas TiO2 and new organic UV filters showed much weaker toxicity effects.
Bioassays were performed to research the potential and relative toxicity of different sunscreen products on marine organisms from various trophic levels. Multiple acute and chronic bioassays were performed on Vibrio fischeri bacteria, Brachionus plicatilis rotifers and Skeletonema constatum algae. This resulted in a clear pattern where eco-friendly show very weak to no relative toxicity effects in the bioassays, whereas the tested products which didn’t claim to be eco-friendly showed much stronger relative toxicity effects.
A risk assessment was performed for the case Lac Bay, a touristic hotspot in Bonaire. Estimations on the potential daily emissions of eco-friendly sunscreen products were made and compared to the toxicity data to calculate risk quotients indicating a potential environmental risk for the case. The outcome was that both nano and non-nano ZnO form a potential environmental risk for the case of Lac Bay. However nano-TiO2 forms no risk. Furthermore it was not possible to perform the risk assessment for the other UV filters, because toxicity data was limited.
Answering the main question results in the following conclusion. From the three approaches the toxicity data and the risk assessment indicates that both nano and non-nano ZnO, which are most used in eco-friendly sunscreen products, show strong toxicity and form a potential environmental risk. Whereas the bioassays show that all eco-friendly sunscreen products show weak to no relative toxicity compared to the not eco-friendly products, which show strong relative toxicity in the bioassays.