The Effects of Erythema on Near-Infrared Absorption Spectra

The accute effets of sun-bathing on the near-infrared absorption spectra of skin was studied by exposuring the shoulders of a male volunteer to bright Finnish midsummer midday sun and measuring the spectra before and after the exposure and on several days after the exposure. Several spectra processing and classification methods were applied on the data set to find the differences caused by the sun exposure. The spectrophotometer and measuring procedure were found to cause some systematic errors that were reduced computationally. It is however more advisable to avoid such errors by careful handling of the spectrometer device and overall design of the skin measurement protocol. This paper discusses the effects of sun exposure to skin and its near-infrared spectra, difficulties and remedies of skin measurements, promising computational methods, and results.