ACCURACY AND REPRODUCIBILITY OF CALIBRATIONS ON THE SKIN USING THE FIVES FLUORESCENCE MONITOR

Dermal contamination from products such as pesticide formulations may be measured by adding a fluorescent dye as a tracer, and photographing the glow of the dye on the skin under ultraviolet light. The Fluoresc ence Interactive Video Exposure System (FIVES) fluorescence monitor, d eveloped at the Health and Safety Laboratory, uses calibrations of int ensity of glow against surface concentration of dye which are affected by the natural fluorescence of the skin and by skin hue. Calibrations of two dye/product mixtures upon the skin of several volunteers showe d that a simple multiplicative correction procedure aligned all the re sponses to one calibration curve for each mixture. The palms of the ha nds were an exception, because their natural fluorescence was much hig her than other areas of skin, and the relation no longer held. A furth er correction factor aligned their responses with the rest. The calibr ation data were fitted best by log-log polynomials, although linear po lynomials were acceptable. Using this new procedure, the FIVES monitor could estimate dermal contamination to within +/-70% of known applied doses. Upon exposure to light, the dyes on the skin were found to fad e by 20% in 1/2 h, but no further in 1 h. The procedure and calibratio ns developed here were used in an experiment to estimate the likely de rmal exposures of amateur or occasional biocide users, painting ready- to-use wood preservative fluids onto a trellis fence outdoors. Crown c opyright (C) 1997 Published by Elsevier Science Ltd.