Evaluation Of Personal Exposure Research Articles

Quantitative evaluation of personal exposure to UV radiation of workers and general public

Due to meteorological conditions variability and to the variability of exposure patterns, which can be largely different during a working day, personal dosemeters use can be necessary to obtain a correct quantitative evaluation of the radiation dose absorbed by an exposed worker. Different classes of personal dosemeters exist and, among them, electronic dosemeters and polysulphone film dosemeters. An experimental campaign is presented conduced in a cultivated area of Tuscany and some aspects are discussed about an experimental campaign performed on a population of volunteers on a central Italy beach near Rome. The aim of the present work is to show some relevant issues in a dosimetric approach to the exposure evaluation of outdoor workers and, in general, of the public during recreational activities.

Exposure to Refractory Ceramic Fibres in the Metal Industry

Refractory ceramic fibres (RCF) are used in thermal isolation in the metal industry where high temperatures are regularly employed. Asbestos materials were earlier commonly used for these purposes. In this work, two Finnish steel plants, three foundries and a repair shop were studied for the ceramic fibre exposure of their workers under normal production and during the replacement of oven insulation. Personal and stationary sampling was used together with a novel nasal lavage sampling for the evaluation of personal exposure. Fibres were counted with optical and electron microscopy and they were identified using an energy-dispersive X-ray analyser. Ceramic fibres were found in most production phases [range <0.01-0.29 fibres per cubic centimetre (f cm(-3))]. Considerably higher fibre counts were obtained during the maintenance work (range <0.01-14.2 f cm(-3)). Nasal sampling was found to correlate with the airborne fibre concentrations at the group level. The mean fibre concentrations varied from 34 to 6680 f ml(-1) of lavage liquid. Use of personal respiratory protectors diminished the exposure on the average as analysed in the lavage specimens, but the effect of respirator use did not appear clearly in the results. Because of the heat conditions, the workers used the respirators for a strict minimum period. A considerable exposure to RCF occurs in the studied plants. Its risk should be evaluated and managed more closely in view that the material is carcinogenic. Use of personal respiratory protectors should be encouraged. Their effective use could be verified by the nasal sampling for fibres after the work shift.

Urinary metabolite levels in workers handling p-tert-butylphenol as an index of personal exposure.

Occupational exposure to p-tert-butylphenol (PTBP) was studied in a workplace where workers were engaged in packing this alkylphenol in bags or transporting the bags by fork-lift. The geometrical mean of eight-hour-time-weighted-average (8 h-TWA) value for personal ambient PTBP level of the packers was 0.39 mg/m3 (n = 15), higher than that of the carriers (0.10 mg/m3, n = 5). Amounts of PTBP collected in the respirators used by the workers were in proportion to the 8 h-TWA values but lower than the estimated theoretical amounts; considerable amounts of PTBP were assumed to be absorbed through the respiratory tract. The urine excreted during the latter half of the shift showed the highest levels of PTBP (geometrical mean: packer, 5.07 micrograms/ml, n = 20; carrier, 3.03 micrograms/ml, n = 8). When the workers were away from the workplace, PTBP levels decreased; most was excreted within 24 h. Correlation between the urinary PTBP levels and 8 h-TWA values was significant (r = 0.46, n = 19, P less than 0.05), but its extent was weak. The total amounts of urinary PTBP excreted for 24 h after the start of the shift were two to three times higher than the estimated respiratory absorption of PTBP; PTBP was assumed to be absorbed not only through the respiratory tract but also through intact skin. It was concluded that the personal ambient PTBP level is not a suitable index for personal exposure, and biological monitoring via the PTBP level in the urine excreted at the end of the each shift is useful for the evaluation of personal exposure.