Are sunscreens a new environmental risk associated with coastal tourism?

The world coastal-zone population and coastal tourism are expected to grow during this century. Associated with that, there will be an increase in the use of sunscreens and cosmetics with UV-filters in their formulation, which will make coastal regions worldwide susceptible to the impact of these cosmetics. Recent investigations indicate that organic and inorganic UV-filters, as well as many other components that are constituents of the sunscreens, reach the marine environment--directly as a consequence of water recreational activities and/or indirectly from wastewater treatment plants (WWTP) effluents. Toxicity of organic and inorganic UV filters has been demonstrated in aquatic organism. UV-filters inhibit growth in marine phytoplankton and tend to bioaccumulate in the food webs. These findings together with coastal tourism data records highlight the potential risk that the increasing use of these cosmetics would have in coastal marine areas. Nevertheless, future investigations into distribution, residence time, aging, partitioning and speciation of their main components and by-products in the water column, persistence, accumulation and toxicity in the trophic chain, are needed to understand the magnitude and real impact of these emerging pollutants in the marine system.