Unità Clinica Operativa di Medicina del Lavoro, Dipartimento di Scienze di Medicina Pubblica, Azienda Ospedaliero-Universitaria "Ospedali Riuniti di Trieste", Università di Trieste, Centro Tumori, Via della Pietà 19, I-34129 Trieste, Italy.
Occup Environ Med. 2010 Jan;67(1):38-46. doi: 10.1136/oem.2009.046128. Epub 2009 Jun 14.
To investigate prospectively the relation between vibration-induced white finger (VWF) and measures of cumulative (lifetime) exposure to hand-transmitted vibration (HTV).
Two hundred and forty-nine HTV workers and 138 control men of the same companies participated in a 3-year follow-up study. The diagnosis of VWF (Raynaud's phenomenon in the controls) was based on the medical history, the administration of colour charts and the results of a cold test. Tool vibration magnitudes were expressed as root-mean-square (r.m.s.) acceleration, frequency-weighted according to international standard ISO 5349-1 and also unweighted over the frequency range 6.3-1250 Hz. From the vibration magnitudes and exposure durations, alternative measures of cumulative vibration dose were calculated for each HTV worker, according to the expression: dose = Sigmaa(i)(m)t(i), where a(i) is the acceleration magnitude on tool i, t(i) is the lifetime exposure duration (hours) for tool i, and m = 0, 1, 2 or 4.
The incidence of VWF varied from 5 to 6% in the HTV workers versus 0 to 1.5% for Raynaud's phenomenon in the controls. After adjusting for potential confounders, measures of cumulative vibration dose derived from total operating hours and high powers of unweighted acceleration (ie, , with m>1) gave better predictions of the occurrence of VWF than dose measures calculated from frequency-weighted acceleration (ie, ). These findings were observed in the entire sample of HTV workers, in those with no VWF at the initial investigation, and in those with normal cold test results at baseline.
This prospective cohort study suggests that measures of cumulative vibration doses constructed from unweighted r.m.s. acceleration perform better for the prediction of VWF than dose measures calculated according to the recommendations of current standards. These findings should contribute to the improvement of the ISO frequency weighting for evaluating the severity of hand-transmitted vibration.
前瞻性研究振动诱导白指（VWF）与手部接触振动（HTV）累积（终生）暴露测量值之间的关系。
249 名 HTV 工人和 138 名同公司的对照男性参加了为期 3 年的随访研究。VWF（对照组雷诺现象）的诊断基于病史、彩色图表的管理以及冷试验结果。工具振动幅度表示为均方根（r.m.s.）加速度，根据国际标准 ISO 5349-1 进行频率加权，也在 6.3-1250 Hz 的频率范围内进行未加权。根据表达式：剂量=Σa(i)(m)t(i)，从振动幅度和暴露时间计算每个 HTV 工人的累积振动剂量的替代测量值，其中 a(i)是工具 i 的加速度幅度，t(i)是工具 i 的终生暴露时间（小时），m=0、1、2 或 4。
HTV 工人的 VWF 发生率为 5%至 6%，而对照组的雷诺现象发生率为 0%至 1.5%。在调整潜在混杂因素后，总工作时间和未加权加速度高次幂（即，m>1）得出的累积振动剂量测量值比频率加权加速度（即，）得出的剂量测量值更好地预测了 VWF 的发生。这些发现见于整个 HTV 工人样本、初始研究时无 VWF 的工人样本以及基线时冷试验结果正常的工人样本。
这项前瞻性队列研究表明，从未加权 r.m.s.加速度构建的累积振动剂量测量值在预测 VWF 方面优于根据当前标准建议计算的剂量测量值。这些发现应该有助于改进 ISO 频率加权以评估手部接触振动的严重程度。
