Paustenbach D J, Bass R D, Price P
McLauren/Hart Environmental Engineering, ChemRisk Division, Alameda, CA 94062.
Environ Health Perspect. 1993 Dec;101 Suppl 6(Suppl 6):177-200. doi: 10.1289/ehp.93101s6177.
Acute and chronic exposure to benzene vapors poses a number of health hazards to humans. To evaluate the probability that a specific degree of exposure will produce an adverse effect, risk assessment methods must be used. This paper reviews much of the published information and evaluates the various risk assessments for benzene that have been conducted over the past 20 years. There is sufficient evidence that chronic exposure to relatively high concentrations of benzene can produce an increased incidence of acute myelogenous leukemia (AML). Some studies have indicated that benzene may cause other leukemias, but due to the inconsistency of results, the evidence is not conclusive. To predict the leukemogenic risk for humans exposed to much lower doses of benzene than those observed in most epidemiology studies, a model must be used. Although several models could yield plausible results, to date most risk assessments have used the linear-quadratic or conditional logistic models. These appear to be the most appropriate ones for providing the cancer risk for airborne concentrations of 1 ppb to 10 ppm, the range most often observed in the community and workplace. Of the seven major epidemiology studies that have been conducted, there is a consensus that the Pliofilm cohort (rubber workers) is the best one for estimating the cancer potency because it is the only one with good exposure and incidence of disease data. The current EPA, OSHA, and ACGIH cancer potency estimates for benzene are based largely on this cohort. A retrospective exposure assessment and an analysis of the incidence of disease in these workers were completed in 1991. All of these issues are discussed and the implications evaluated in this paper. The range of benzene exposures to which Americans are commonly exposed and the current regulatory criteria are also presented.
急性和慢性接触苯蒸气会对人类造成多种健康危害。为评估特定程度的接触产生不良影响的可能性，必须使用风险评估方法。本文回顾了大量已发表的信息，并评估了过去20年中对苯进行的各种风险评估。有充分证据表明，长期接触相对高浓度的苯会导致急性髓性白血病（AML）发病率增加。一些研究表明，苯可能会引发其他白血病，但由于结果不一致，证据并不确凿。为预测接触苯剂量远低于大多数流行病学研究中所观察到剂量的人群患白血病的风险，必须使用一个模型。尽管有几种模型可能会得出合理的结果，但迄今为止，大多数风险评估都使用了线性二次模型或条件逻辑模型。对于空气中浓度在1 ppb至10 ppm之间（这是社区和工作场所中最常观察到的范围）的苯，这些模型似乎是提供癌症风险的最合适模型。在已进行的七项主要流行病学研究中，人们一致认为普利菲姆队列研究（橡胶工人）是评估致癌效力的最佳研究，因为它是唯一拥有良好接触数据和疾病发病率数据的研究。美国环境保护局（EPA）、职业安全与健康管理局（OSHA）以及美国政府工业卫生学家会议（ACGIH）目前对苯的致癌效力估计很大程度上基于该队列研究。1991年完成了对这些工人的回顾性接触评估以及疾病发病率分析。本文讨论了所有这些问题并评估了其影响。还介绍了美国人普遍接触的苯暴露范围以及当前的监管标准。
