Crump K S
ICF Kaiser International, Ruston, Louisiana 71270, USA.
Environ Health Perspect. 1996 Dec;104 Suppl 6(Suppl 6):1437-41. doi: 10.1289/ehp.961041437.
This report updates the risk assessment by Crump and Allen for benzene-induced leukemia that was based on a cohort exposed to benzene in the manufacture of Pliofilm. The present study derives new risk estimates using data from follow-up through 1987 (whereas the earlier assessment only had follow-up available through 1978) and uses new exposure information for this cohort developed by Paustenbach et al. that accounts for a number of factors that were unknown or not fully evaluated in earlier exposure assessments. There was a significant excess of acute myelocytic or acute monocytic leukemia (AMML) (8-10 observed, 1.61 expected) in this cohort, and this end point also exhibited a strong dose-response trend. No other types of lymphatic or hematopoietic cancer were clearly linked to benzene exposure. Quantitative risk estimates were robust with respect to whether AMML or all leukemia was being modeled. They were also robust with respect whether the Paustenbach et al. or Crump and Allen exposure estimates were used (differences in risk estimates of no greater than 2-fold) as long as linear dose-response models were applied. However, whereas the Crump and Allen exposures predicted a linear dose response, the Paustenbach et al. exposures predicted a quadratic dose response. This departure from linearity was borderline significant (p = 0.08). Estimates of additional lifetime from 45 years of occupational exposure (lifetime exposure) to 1 ppm derived using he Paustenbach et al. exposure matrix and best-fitting (quadratic) models ranged from 0.020 to 0.036 per thousand, whereas corresponding estimates based on a linear dose response ranged from 1.6 to 3.1 per thousand.
本报告更新了Crump和Allen对苯所致白血病的风险评估，该评估基于在制造赛璐玢过程中接触苯的一个队列。本研究使用截至1987年随访的数据得出新的风险估计值（而早期评估仅有截至1978年的随访数据），并使用Paustenbach等人为此队列编制的新的暴露信息，该信息考虑了早期暴露评估中未知或未充分评估的一些因素。该队列中急性髓细胞性或急性单核细胞性白血病（AMML）显著超额（观察到8 - 10例，预期1.61例），且该终点也呈现出强烈的剂量反应趋势。没有其他类型的淋巴或造血系统癌症与苯暴露有明确关联。无论对AMML还是所有白血病进行建模，定量风险估计都是稳健的。只要应用线性剂量反应模型，无论使用Paustenbach等人还是Crump和Allen的暴露估计值（风险估计差异不超过2倍），结果都是稳健的。然而，Crump和Allen的暴露预测为线性剂量反应，而Paustenbach等人的暴露预测为二次剂量反应。这种偏离线性的情况接近显著水平（p = 0.08）。使用Paustenbach等人的暴露矩阵和最佳拟合（二次）模型得出的从45年职业暴露（终生暴露）于1 ppm苯导致的额外终生风险估计范围为千分之0.020至0.036，而基于线性剂量反应的相应估计范围为千分之1.6至3.1。
