Atzeri S, Vacca L
Istituto di Medicina del Lavoro, Università di Cagliari.
Med Lav. 1997 Jan-Feb;88(1):37-48.
Personal monitoring of noise exposure was conducted in a small dry dock, where mainly tug-boats and high sea fishing-boats are refitted. Manual tools were the prevalent noise sources. Noise exposure could be affected and amplified by factors extraneous to workers' tasks. The workers might be employed in different jobs simultaneously also in confined and small areas, and were mainly involved in non-routine tasks. Six different tasks were investigated: dry-dock supervisor, welder/ship-wrights, painters, electricians, woodworkers and unskilled workers. The number of workers employed in the tasks, with the exclusion of the supervisor, might change from day to day according to the particular work phase carried out on the boat. Daily personal exposure was measured using Larson Davis mod. 700 integrating sound level meters. The all shift time history of short equivalent continuous sound level with 10 s integrating time was collected for each selected worker. A 1/2 inch microphone was attached to the helmet at a distance of 11 +/- 1 cm from the right outer ear. Measurements were repeated over 13 days and randomly distributed over about four months. The number of data-points collected was nine for the supervisor, twenty-seven for the welders, eighteen for the painters, twelve for the electricians, six for the woodworkers and eleven for the unskilled workers. Ranges of the daily noise exposure level were from 15 to 30 dBA for all tasks, with the exclusion of the woodworkers. The time histories relative to workers grouped in the same task were matched to verify the correlation. The daily exposure levels derived from correlated samples were substituted by their arithmetic mean. The analysis of variance applied to experimental distributions of daily exposure for four of the welders indicates that the difference of means (p > 0.3) is not significant. A similar conclusion is reached for painters when only this task is considered. If we take into account the exposures of painters employed also in different tasks, the probability is included in a range of lower significance, between 0.1 and 0.05. The experimental distributions of daily noise exposure for all tasks fit the normal distribution. The Kolmogorov-Smirnov test was used at a p > 0.1 confidence level. These results may have an important role in defining sampling strategies for collecting noise exposure data both for compliance and epidemiological purposes.
在一个小型干船坞进行了噪声暴露的个人监测，该干船坞主要对拖船和远洋渔船进行改装。手动工具是主要的噪声源。噪声暴露可能会受到与工人任务无关的因素的影响和放大。工人可能同时在不同的工作岗位工作，且工作区域狭窄，主要从事非常规任务。研究了六种不同的任务：干船坞主管、焊工/造船工人、油漆工、电工、木工和非技术工人。除主管外，从事这些任务的工人数量可能会根据船上进行的特定工作阶段每天发生变化。使用 Larson Davis mod. 700 积分声级计测量每日个人暴露量。为每个选定的工人收集了积分时间为 10 秒的短等效连续声级的全时段时间历程。一个 1/2 英寸的麦克风安装在头盔上，距右外耳 11 +/- 1 厘米处。测量在 13 天内重复进行，并随机分布在大约四个月的时间里。收集到的数据点数量，主管为 9 个，焊工为 27 个，油漆工为 18 个，电工为 12 个，木工为 6 个，非技术工人为 11 个。除木工外，所有任务的每日噪声暴露水平范围为 15 至 30 dBA。将同一任务组中的工人的时间历程进行匹配以验证相关性。相关样本得出的每日暴露水平用其算术平均值代替。对四名焊工的每日暴露实验分布进行方差分析表明，均值差异（p > 0.3）不显著。仅考虑油漆工这项任务时，也得出了类似的结论。如果考虑到同时从事不同任务中的油漆工的暴露情况，概率处于较低显著性范围，即 0.1 至 0.05 之间。所有任务的每日噪声暴露实验分布均符合正态分布。使用 Kolmogorov-Smirnov 检验，置信水平为 p > 0.1。这些结果在确定用于合规性和流行病学目的的噪声暴露数据收集抽样策略方面可能具有重要作用。
