Coleman Patrick J, Kerkering John C
National Institute for Occupational Safety and Health, Spokane Research Laboratory, USA.
J Safety Res. 2007;38(5):523-33. doi: 10.1016/j.jsr.2007.06.005. Epub 2007 Oct 16.
Mining in the United States remains one of the most hazardous industries, despite significant reductions in fatal injury rates over the last century. Coal mine fatality rates, for example, have dropped almost a thousand-fold since their peak in 1908. While incidence rates are very important indicators, lost worktime measures offer an alternative metric for evaluating job safety and health performance. The first objective of this study examined the distributions and summary statistics of all injuries reported to the Mine Safety and Health Administration from 1983 through 2004. Over the period studied (1983-2004), there were 31,515,368 lost workdays associated with mining injuries, for an equivalent of 5,700 person-years lost annually. The second objective addressed the problem of comparing safety program performance in mines for situations where denominator data were lacking. By examining the consequences of injuries, comparisons can be made between disparate operations without the need for denominators. Total risk in the form of lost workday sums can help to distinguish between lower- and higher-risk operations or time periods.
Our method was to use a beta distribution to model the losses and to compare underground coal mining to underground metal/nonmetal mining from 2000 to 2004.
Our results showed the probability of an injury having 10 or more lost workdays was 0.52 for coal mine cases versus 0.35 for metal/nonmetal mine cases. In addition, a comparison of injuries involving continuous mining machines over 2001-2002 versus 2003-2004 showed that the ratio of average losses in the later period to those in the earlier period was approximately 1.08, suggesting increasing risks for such operations.
This denominator-free safety measure will help the mining industry more effectively identify higher-risk operations and more realistically evaluate their safety improvement programs.
Attention to a variety of metrics concerning the performance of a job safety and health program will enhance industry's ability to manage these programs and reduce risk.
尽管在上个世纪美国煤矿业的致命伤发生率大幅下降，但采矿业仍是最危险的行业之一。例如，自1908年达到峰值以来，煤矿死亡率已下降了近千倍。虽然发生率是非常重要的指标，但误工时间衡量标准为评估工作安全与健康绩效提供了另一种衡量尺度。本研究的首要目标是考察1983年至2004年期间向矿山安全与健康管理局报告的所有工伤事故的分布情况及汇总统计数据。在研究期间（1983 - 2004年），因采矿工伤事故导致的误工天数达31,515,368天，相当于每年损失5,700人年的劳动力。第二个目标是解决在缺乏分母数据的情况下比较矿山安全计划绩效的问题。通过考察工伤事故的后果，可以在无需分母数据的情况下对不同作业进行比较。以误工天数总和形式体现的总风险有助于区分低风险和高风险作业或时间段。
我们的方法是使用贝塔分布对损失进行建模，并比较2000年至2004年期间地下煤矿开采与地下金属/非金属矿开采情况。
我们的结果表明，煤矿工伤事故导致10天及以上误工天数的概率为0.52，而金属/非金属矿工伤事故的这一概率为0.35。此外，对2001 - 2002年与2003 - 2004年期间涉及连续采矿机的工伤事故进行比较发现，后期平均损失与前期平均损失的比率约为1.08，这表明此类作业的风险在增加。
这种无需分母的安全衡量标准将有助于采矿业更有效地识别高风险作业，并更实际地评估其安全改进计划。
关注与工作安全和健康计划绩效相关的各种衡量标准将提高行业管理这些计划并降低风险的能力。
