International Epidemiology Institute, Rockville, MD, USA.
Vanderbilt Institute for Clinical and Translational Research, Vanderbilt University Medical Center, Nashville, TN, USA.
Int J Radiat Biol. 2022;98(4):786-794. doi: 10.1080/09553002.2019.1642540. Epub 2019 Jul 22.
The risk of mesothelioma, including cancers of the pleura and peritoneum, was examined within two large cohorts of workers monitored for exposure to ionizing radiation.
Mortality was assessed among 253,632 workers routinely monitored for external radiation, including 30,724 industrial radiographers (IR) at shipyards, 142,583 workers at nuclear power plants (NPP), and 83,441 IR who had not worked at an NPP or shipyard. Follow-up was from 1969 through 2011. Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were computed; observed numbers of deaths from mesothelioma (including cancers of the pleura and peritoneum) and asbestosis were compared with numbers expected based on age-, sex-, and calendar year-specific national mortality rates. Job history and quantitative asbestos exposure data were unavailable, but work at a shipyard was taken as a surrogate for the likelihood of exposure. Cox proportional hazards models were used to estimate hazard ratios (HRs) for mesothelioma in relation to estimated cumulative radiation exposure to the lung.
The mean duration of follow-up was 25.3 years (max 42 years). The mean cumulative lung dose was 28.6 mGy (7.3% > 250 mGy). Nearly 20% of the workers had died by 2011. A total of 421 mesothelioma deaths were found (75% occurring after 1999) with increased SMRs among workers monitored in shipyards (SMR 9.97; 95% CI 8.50-11.63) and for NPP workers (SMR 5.55; 95% CI 4.88-6.29), but not for IR who had not worked in shipyards (SMR 1.15; 95% CI 0.53-2.19). Likewise, deaths from asbestosis ( = 189) were also increased for shipyard and NPP workers (SMR = 18.1 and 9.2, respectively), but not among workers who never worked at a shipyard or NPP (SMR = 0.70; = 1). Radiation dose to the lung was not associated with a statistically meaningful dose-response trend for mesothelioma in the combined cohorts (HR at 100 mGy = 1.10; 95% CI 0.96-1.27; = .18), nor was mesothelioma risk associated with radiation exposure among IR who had not worked in a shipyard and assumed minimally exposed to asbestos.
An elevated rate of death from mesothelioma was observed in two radiation-exposed occupational groups with potential for asbestos exposure. The increased risk of death from asbestosis, combined with little evidence of a rising trend in mesothelioma mortality with increasing radiation exposure, suggests that the mesothelioma (and asbestosis) excess in these workers was due to asbestos exposure in shipyards and power plants and not to occupational low-dose radiation.
在两个监测电离辐射暴露的大型队列中，研究了间皮瘤（包括胸膜和腹膜癌）的风险。
对 253632 名常规监测外部辐射的工人的死亡率进行了评估，其中包括造船厂的 30724 名工业放射技师（IR）、142583 名核电站（NPP）工人和 83441 名未在 NPP 或造船厂工作过的 IR。随访时间从 1969 年到 2011 年。计算了标准化死亡率比（SMR）和 95%置信区间（CI）；观察到的间皮瘤（包括胸膜和腹膜癌）和石棉沉着病死亡人数与基于年龄、性别和日历特定国家死亡率的预期死亡人数进行了比较。工作史和定量石棉暴露数据不可用，但将在造船厂工作视为接触石棉的可能性的替代指标。使用 Cox 比例风险模型估计与肺累积辐射暴露相关的间皮瘤的风险比（HR）。
平均随访时间为 25.3 年（最长 42 年）。平均累积肺剂量为 28.6 mGy（7.3%>250 mGy）。到 2011 年，近 20%的工人已经死亡。共发现 421 例间皮瘤死亡（75%发生在 1999 年后），造船厂监测工人的 SMR 较高（SMR 9.97；95%CI 8.50-11.63）和 NPP 工人（SMR 5.55；95%CI 4.88-6.29），但未在造船厂工作的 IR 工人则没有（SMR 1.15；95%CI 0.53-2.19）。同样，造船厂和 NPP 工人的石棉沉着病死亡（ = 189）也有所增加（SMR 分别为 18.1 和 9.2），但从未在造船厂或 NPP 工作过的工人则没有（SMR 0.70； = 1）。肺内辐射剂量与合并队列中间皮瘤的统计学意义剂量-反应趋势无关（100 mGy 时 HR = 1.10；95%CI 0.96-1.27； = .18），也与未在造船厂工作且假定最小暴露于石棉的 IR 中的辐射暴露无关。
在两个有潜在石棉暴露的电离辐射暴露职业群体中，观察到间皮瘤死亡的风险增加。石棉沉着病死亡风险的增加，加上间皮瘤死亡率随辐射暴露增加而没有明显上升趋势的证据，表明这些工人的间皮瘤（和石棉沉着病）过多是由于造船厂和发电厂的石棉暴露，而不是职业性低剂量辐射。
