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Fifteen human volunteers were exposed to methyl ethyl ketone (MEK) vapor at 11.9-621.8 mg/m3 for a period of 2 to 4 hours at rest (ten cases) and during light physical exercise (five cases). Subsequently 78 workers occupationally exposed to MEK in a manufacture of leather suitcases (median value: 75.5 mg/m3; geometrical standard deviation: 3.12 mg/m3; range: 6-790) were studied. The analyses were performed by means of a Gas Chromatograph (GC) Hewlett-Packard 5880 A connected with a Mass Selective Detector (MSD). The relative uptake (R) of MEK was about 0.54 (standard deviation: 0.05) and it keeps practically constant either at rest or during light effort (V < 30 L/min). A linear relationship existed in the experimentally exposed subjects between urinary concentration (Cu) and amount of MEK absorbed (U) (Cu = 3.05 x U-162.1; r = 0.95; n = 15) (Cu = micrograms/L; U = mg). Both in the experimentally exposed subjects and in the occupationally exposed workers, the urinary concentration of MEK shoved a linear relationship to the corresponding environmental time-weighted average concentration (CI). The correlation coefficients (r) were 0.93 in occupationally exposed subjects (regression equation: Cu = 0.004 x CI + 0.118; n = 78); Cu = mg/L; CI = mg/m3) and more than 0.93 in experimentally exposed groups. The findings indicate that the urinary concentration of MEK can be used as an appropriate biological exposure indicator.(ABSTRACT TRUNCATED AT 250 WORDS)

Results of a longitudinal study on the yearly decline of two pulmonary parameters are reported. All subjects were workers in a refractory material factory and exposed to dust with low silica content. The study brought about an annual measurement of two spirometric parameters (VC and FEV1) during a 13 year period of follow up on 113 subjects. 56% and 57.5% of them showed annual decreases of VC and FEV1 statistically significant. The trend of the two functional parameters over time was studied both in the whole group of workers and in subgroups obtained from occupational exposure levels, smoking habit, age. The most affected volumetric index was the VC. The 3 risk indicators considered (occupational exposure, smoking habit and age) all negatively influence the VC decrease; however, the effect is statistically significant only for smoking habit. The FEV1 changes with reference to the above mentioned risk indicators are less clear. From the whole group a number of 15 losers were selected.

A method is described for measuring, by a single test, some functional respiratory indexes, such as lung volumes, dynamic tests (flow-volume curve included), rapid He and CO2 curves, "closing volume". The normal values of "closing volume" and of forced expiratory flows obtained in 114 healthy subjects (65 men and 49 women) are then reported. Such values are comparable to those obtained by other authors. An equipment is used by the authors which is easily transportable to the workplace; their method can therefore be used for surveys of workers exposed to occupational respiratory risk during a working shift. The described respiratory index should be able to detect in a pre-clinical stage the early functional changes in chronic bronchitis.

The long-term occupational exposure to inhalation anaesthetics might represent a health hazard; mainly it may have an adverse effect on the reproductive outcome. Nitrous oxide is the anaesthetic employed in the largest amount during general anaesthesia and it can be used as an indicator of occupational exposure to all the components the mixture; but if the pattern of dispersion of them (when leaking into the operating theater) are not the same, two indicators should be used: N2O (gas) + another component the mixture (vapour). Our results concern practically 5 points: --Analysis of N2O by means of a diffusive personal sampler (comparison with a conventional sampling method) --Analysis of N2O in urine collected after 4 hours of exposure during routine anaesthetic work (headspace method) --Comparison of environmental and biological data concerning N2O --Comparison of environmental and biological data concerning a component of the anaesthetic mixture, forane --Proposal of biological exposure indices for nitrous oxide and forane. A close relationship between air and urine was found in 363 subjects occupationally exposed to N2O and 45 subjects exposed to forane (r: 0.95 and 0.90 respectively). On the basis of such a relationship the biological exposure index for N2O corresponding to an ambient concentration of 100 ppm (European limit) turned out to be 55 micrograms/L; the ones for forane corresponding to ambient concentrations of 2 or 10 ppm are respectively 3.4 or 14.5 micrograms/L (urinary concentrations in samples collected after 4 hours of exposure).

The authors report the prevalence of respiratory function changes in two groups of workers employed in bichromate and chromic acid production. In the first group (82 subjects) examined at the Institute of Occupational Medicine, the following tests were performed: filling out of a questionnaire for cronic bronchitis; chest x-ray; spirometry; pulmonary diffusing capacity (DLco) measurement; blood gas analysis on arteriolized capillary; He and CO2 rapid expiratory curves determination. No environmental pollution data were available. In the second group (180 subjects) examined at the working site, the following tests were performed: filling out of a questionnaire -or chronic bronchitis; spirometric determination. Environmental pollution data were available. A causal connection is hypothesized by the authors between either roentgenologic or respiratory functional changes and chromium exposure, and an increased proportion between lung function changes and exposure length is stressed.