Sunscreens in Coastal Ecosystems. Chapter:Fate and behavior of uv filters in the marine environment

UV filters are released into the coastal areas by a combination of different sources, including wastewater discharges and direct input related to recreational activities. To fully understand the risks associated with the occurrence of UV filters in the marine environment, better knowledge on their distribution and environmental behavior is required. So far, concentrations of several parts per trillion have been reported in different marine settings from touristic areas. Temporal variations in levels for organic UV filters have been associated with beach use, whereas for inorganic UV filters a preferential accumulation in the surface microlayer was observed. The latter are often released as nanoparticles, which have a tendency to form aggregates and precipitate. Due to their relatively high hydrophobicity, organic UV filters can also end up in the seafloor. Although sediments are not so frequently monitored at seawater, higher UV-filter levels (a few ng g−1) are usually found. Regarding their reactivity in the marine environment, the elucidation of degradation pathways and kinetics is still mostly unknown, although photochemical degradation seems to be a major transformation route for most organic UV filters. Regarding inorganic UV filters, their nanoparticles are subjected to weathering or aging and have also tendency to generate free radicals such as hydrogen peroxide under solar irradiatio