Raabe G K, Wong O
Medical Department, Mobil Oil Corporation, New Hope, Pennsylvania 18938, USA.
Environ Health Perspect. 1996 Dec;104 Suppl 6(Suppl 6):1381-92. doi: 10.1289/ehp.961041381.
Workers in the petroleum industry are potentially exposed to a variety of petrochemicals, including benzene or benzene-containing liquids. Although a large number of studies of petroleum workers have been conducted to examine leukemia and other cancer risks, few existing studies have investigated cell-type-specific leukemias. One of the major reasons for the lack of cell-type-specific analysis was the small number of deaths by cell type in individual studies. In the present investigation, all cohort studies of petroleum workers in the United States and the United Kingdom were combined into a single database for cell-type-specific leukemia analysis. The majority of these workers were petroleum refinery employees, but production, pipeline, and distribution workers in the petroleum industry were also included. The combined cohort consisted of more than 208,000 petroleum workers, who contributed more than 4.6 million person-years of observation. Based on a meta-analysis of the combined data, cell-type-specific leukemia risks were expressed in terms of standardized mortality ratios (meta-SMRs). The meta-SMR for acute myeloid leukemia was 0.96. The lack of an increase of acute myeloid leukemia was attributed to the low levels of benzene exposure in the petroleum industry, particularly in comparison to benzene exposure levels in some previous studies of workers in other industries, who had been found to experience an increased risk of acute myeloid leukemia. Similarly, no increase in chronic myeloid, acute lymphocytic, or chronic lymphocytic leukemias was found in petroleum workers (meta-SMRs of 0.89, 1.16, and 0.84, respectively). Stratified meta-analyses restricted to refinery studies or to studies with at least 15 years of follow-up yielded similar results. The findings of the present investigation are consistent with those from several recent case-control studies of cell-type-specific leukemia. Patterns and levels of benzene exposure in the petroleum industry are reviewed. The results of the present epidemiologic investigation are discussed in conjunction with recent advances in leukemogenesis from other scientific disciplines.
石油行业的工人可能会接触到各种石化产品，包括苯或含苯液体。尽管已经对石油工人进行了大量研究以检查白血病和其他癌症风险，但现有研究中很少有调查特定细胞类型白血病的。缺乏特定细胞类型分析的主要原因之一是个别研究中按细胞类型划分的死亡人数较少。在本调查中，美国和英国所有关于石油工人的队列研究被合并到一个单一数据库中，用于特定细胞类型白血病分析。这些工人大多数是炼油厂员工，但也包括石油行业的生产、管道和分销工人。合并后的队列由超过20.8万名石油工人组成，他们贡献了超过460万人年的观察数据。基于对合并数据的荟萃分析，特定细胞类型白血病风险以标准化死亡率比（meta-SMR）表示。急性髓系白血病的meta-SMR为0.96。急性髓系白血病没有增加归因于石油行业苯暴露水平较低，特别是与之前一些其他行业工人的研究中的苯暴露水平相比，那些研究发现其他行业工人急性髓系白血病风险增加。同样，在石油工人中未发现慢性髓系、急性淋巴细胞或慢性淋巴细胞白血病增加（meta-SMR分别为0.89、1.16和0.84）。仅限于炼油厂研究或至少有15年随访的研究的分层荟萃分析得出了类似结果。本调查结果与最近几项关于特定细胞类型白血病的病例对照研究结果一致。对石油行业苯暴露的模式和水平进行了综述。结合其他科学学科白血病发生的最新进展讨论了本流行病学调查的结果。
