Department of Epidemiology, College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska, USA.
Occup Environ Med. 2012 Jun;69(6):385-90. doi: 10.1136/oemed-2011-100229. Epub 2012 Jan 20.
Studies of workers in two US cohorts of asbestos textile workers exposed to chrysotile (North Carolina (NC) and South Carolina (SC)) found increasing risk of lung cancer mortality with cumulative fibre exposure. However, the risk appeared to increase more steeply in SC, possibly due to differences in study methods. The authors conducted pooled analyses of the cohorts and investigated the exposure-disease relationship using uniform cohort inclusion criteria and statistical methods.
Workers were included after 30 days of employment in a production job during qualifying years, and vital status ascertained through 2003 (2001 for SC). Poisson regression was used to estimate the exposure-response relationship between asbestos and lung cancer, using both exponential and linear relative rate models adjusted for age, sex, race, birth cohort and decade of follow-up.
The cohort included 6136 workers, contributing 218,631 person-years of observation and 3356 deaths. Cumulative exposures at the four study facilities varied considerably. The pooled relative rate for lung cancer, comparing 100 f-yr/ml to 0 f-yr/ml, was 1.11 (95% CI 1.06 to 1.16) for the combined cohort, with different effects in the NC cohort (RR=1.10, 95% CI 1.03 to 1.16) and the SC cohort (RR = 1.67, 95% CI 1.44 to 1.93).
Increased rates of lung cancer were significantly associated with cumulative fibre exposure overall and in both the Carolina asbestos-textile cohorts. Previously reported differences in exposure-response between the cohorts do not appear to be related to inclusion criteria or analytical methods.
对暴露于温石棉的美国北卡罗来纳州（NC）和南卡罗来纳州（SC）的两个石棉纺织工人队列的工人进行的研究发现，随着累积纤维暴露量的增加，肺癌死亡率的风险也随之增加。然而，在 SC 中，风险似乎增加得更为陡峭，这可能是由于研究方法的差异。作者对这些队列进行了汇总分析，并使用统一的队列纳入标准和统计方法研究了暴露与疾病的关系。
在符合条件的年份中，在生产工作中就业 30 天后，工人将被纳入队列，通过 2003 年（2001 年为 SC）确定存活状态。使用泊松回归估计石棉与肺癌之间的暴露-反应关系，使用指数和线性相对风险模型进行调整，包括年龄、性别、种族、出生队列和随访十年。
该队列包括 6136 名工人，共观察到 218631 人年和 3356 例死亡。四个研究设施的累积暴露量差异很大。与 0 f-yr/ml 相比，组合队列中肺癌的累积相对风险为 1.11（95%CI 1.06 至 1.16），NC 队列的效果不同（RR=1.10，95%CI 1.03 至 1.16），SC 队列的效果为（RR=1.67，95%CI 1.44 至 1.93）。
总的来说，在这两个卡罗来纳州石棉纺织工人队列中，肺癌的发病率与累积纤维暴露量呈显著相关。先前报告的队列之间暴露反应的差异似乎与纳入标准或分析方法无关。
