THE SUITABILITY OF A DYED PLASTIC FILM FOR BIOLOGICALLY EFFECTIVE UVB RADIATION MEASUREMENT

A thin dyed plastic film (thickness, 0.08 mm) was developed and found to be suitable for use as a personal dosimeter for biologically effective solar UVB and UVC radiation. The dosimeter film was fabricated by casting an aqueous solution of poly(vinyl alcohol) and a mixture of colourless hexahydroxyethyl pararosaniline cyanide dye (HPR-CN) and sandolan yellow N-3GL dye (Acid Yellow 75). This flexible plastic film undergoes a colour change from yellow to blue on UV irradiation. The radiation-induced colour was analysed spectrophotometrically at the maximum of the absorption band peaking at 602 nm. The absorption spectra, dose response, dose rate effect, spectral sensitivity and post-irradiation stability of the film dosimeter are discussed. The maximum sensitivity of this new film lies between 280 and 315 nm, in the erythemal region, where most acute and chronic effects of sunlight exposure on biological systems are believed to occur.