Environmental Effects of Ultraviolet (UV) Filters.

Organic and inorganic ultraviolet (UV) filters are used in topical sunscreens and other applications to prevent or limit damage following exposure to UV light. Increasing use of UV filters has contributed to a growing number of investigations examining potential effects on human health and the environment. Worldwide environmental monitoring data demonstrate that UV filters reach aquatic environments through two main input sources - direct (i.e., washoff from swimmers/bathers) and indirect (i.e., incomplete wastewater treatment removal) - and can be taken up by various algal, plant, and animal species and sediments. In areas where industrial wastewater sources or significant recreational activities result in a greater input load, levels may be elevated and could impart an increased risk on native species health. In vitro, at higher levels typically not measured in the environment, effects on growth and reproduction are observed in different species, including fish, coral reef, and plants. Despite this, predicted no-effect concentrations for UV filters are generally above measured environmental concentrations. Recent legislative activity banning the use of certain UV filters has heightened awareness of their environmental ubiquity and precipitated a need for a thorough examination of evidence linking their ecological presence with adverse outcomes. In order to gauge the true potential risk to native ecosystems associated with UV filters, future studies should consider factors inherent both to finished sunscreen products (e.g., metabolic fate/transport and effect of inactive ingredients) and to the sampled environment (e.g., species sensitivity, presence of other contaminants, water flow, and photodegradation).