[Assessment of risk in occupational tasks with exposure to environmental noise of variable duration and intensity]

The discontinuous exposure to environmental working noise often brings about risk situations hardly assessable by means of phonometric measurements and studying the exposure time, even if accurate. The use of the personal dosimetry can simplify the measurements and give a time-weighted value (Leq) comparable to a fixed limit value. Such a measurement is effective only for the considered time (usually a work shift); nevertheless it is assumed to be representative of the usual exposure to the job even though the variability of the working conditions constitute a limiting factor. In this work we tried to verify the possible use of the measurements of environmental sound pressure levels given by the dosimeter every 0.25 sec. The first aim being the study of the type of distribution of these values (during 5 consecutive shifts) and the estimate of mean and standard deviation values. The mean and the standard deviation values were used to get a OTL (one sided tolerance limits) usually employed for assessing the working chemical pollution. The second aim being the compliance control and the possible need of more measurements.