Clothing as protection from ultraviolet radiation: Which fabric is most effective?

Background With increasing levels of solar ultraviolet radiation (UVR) in the earth's near environment and evidence that exposure to UVR contributes to skin cancer, cataracts, and photoaging, protection of the skin is imperative during exposure to the sun. The purpose of this study was to examine the effectiveness of various fabrics in screening UVR and to determine if specific characteristics of fabric are directly related to the amount of protection provided. Methods Transmission of UVR was measured using spectrophotometric techniques. This transmission, as a function of wavelength over the range 250-400 nm, was weighted with solar and biological spectral data to determine a ''sun protection factor'' (SPF) for each fabric. Results The transmission of UVR through fabric depends on the wavelength and varies with factors such as type of fiber, fabric mass, cover, and color. Conclusions Of 28 white fabrics tested, 19 offered less protection than a sunscreen with SPF 15, Polyester fabrics offered increased protection over cotton. The presence of dyes increased protection considerably.