ASSESSMENT OF THE EXPOSURE TO BIOLOGICALLY EFFECTIVE UV-RADIATION USING A DOSIMETRIC TECHNIQUE TO EVALUATE THE SOLAR SPECTRUM

A cost-effective method employing polysulphone, nalidixic acid, 8-meth oxypsoralen and phenothiazine as UV dosimeters is presented for evalua ting the UV spectrum. The exposure measured by each dosimeter is a fun ction of the source spectrum and the spectral response of the material . Each material has a different spectral response and records a differ ent dose for the same exposure. A least squares method is employed to extract the source spectrum from the four dose measurements. A number of spectra have been evaluated, and the differences between these spec tra and the associated irradiances, compared to the spectra and irradi ances measured with a calibrated spectroradiometer is less than 20%. T he technique allows simultaneous multisite measurement at positions th at may be inaccessible to sensitive and expensive equipment. The techn ique was employed to evaluate the spectrum on the chest and shoulder o f four subjects. The erythemal exposures were derived from the evaluat ed spectra with the chest exposures 0.7 to 0.8 those of the shoulder e xposures.