VIBRATION-INDUCED WHITE FINGER AND COLD RESPONSE OF DIGITAL ARTERIAL VESSELS IN OCCUPATIONAL GROUPS WITH VARIOUS PATTERNS OF EXPOSURE TO HAND-TRANSMITTED VIBRATION

Objective This study investigated the relation between vibration expos ure, the prevalence of white fingers, and the cold response of digital arterial vessels in workers using vibrating tools. Methods The change in finger systolic blood pressure (FSBP) at 15 and 10 degrees C as th e percentage of the pressure at 30 degrees C (FSBP%) was measured in 4 55 healthy referents and 822 workers exposed to hand-transmitted vibra tion. Exposure to hand-transmitted vibration was assessed in terms of 8-hour energy-equivalent frequency-weighted acceleration [A(8)] and to tal operating time with vibrating tools. Results The prevalence of whi te fingers was 1.1% for the referents and ranged from 9.0% to 51.6% fo r the vibration-exposed groups. The estimated mean value of A(8) range d between 1.6 (referents) and 8.3 (quarry drillers) m/s(2). After adju stment for age, smoking, and drinking habits, the FSBP% was significan tly lower in the vibration-exposed groups than in the reference group. Groupwise, the FSBP%(10 degrees). was inversely related to the preval ence of white fingers, the estimated A(8), and total operating time. W ith FSBP%(10 degrees) <70% or <60% as the lower normal limit, the sens itivity of the cold test varied from 86% to 100%, with a specificity o f 90% to 94%, and a positive predictive value of 68% to 74%. Conclusio ns FSBP measurement during cold provocation is a useful laboratory tes t for white fingers. A quantitative relationship between cold-induced digital arterial hyperresponsiveness and occupational exposure to hand -transmitted vibration was suggested.