Vibration white finger, digital blood pressure, and some biochemical findings on workers operating vibrating tools in the engine manufacturing industry.

A clinical and laboratory investigation was carried out on 76 operators using pneumatic hand grinders and impact wrenches in the engine manufacturing industry. Twenty-two vibration-exposed workers (28.9%) had no symptoms in the hands (stage 0 of the Stockholm Workshop scale), 34 (44.7%) were affected with sensorineural disturbances in the fingers (stage SN), and 20 (26.3%) suffered from vibration white finger (VWF stages 1-2-3). In the vibration-exposed operators and in 30 comparable referents not exposed to vibration, finger systolic blood pressure (FSP) was measured on a test finger and on a control finger after digit cooling to 30 degrees C and 10 degrees C. The results of the cold provocation test were expressed as percent change of FSP by cooling the test finger from 30 degrees C to 10 degrees C (FSP%t, 10 degrees) and as digital/brachial pressure index during local cooling at 10 degrees C (DPIt, 10 degrees). After cold provocation the mean values of FSP%t, 10 degrees and DPIt 10 degrees were more significantly reduced in the vibration-exposed workers with VWF than in those without VWF and the referents (p less than 0.001). The cold provocation test was found to differentiate between VWF subjects with stages 1-2 and stage 3 (p less than 0.02). It is concluded that the measurement of FSP combined with finger cooling is a useful laboratory test to diagnose objectively Raynaud's phenomenon of occupational origin. The vibration-exposed workers and the referents were also tested for serum levels of immunoglobulins and complement and for daily excretion of urinary free catecholamines. Between the reference and vibration groups no differences in the mean values of the immunologic parameters and urinary catecholamines were found. The meaning of these findings is discussed.