Work Environment Department, University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, USA.
Epidemiology Branch, National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA.
Ann Work Expo Health. 2017 Apr 1;61(3):299-310. doi: 10.1093/annweh/wxw028.
This paper describes the retrospective exposure assessment conducted to assess occupational exposures for the Genes and Environmental Exposures in Veterans (GENEVA) study, a case-control study investigating the joint contribution of genetics and environmental exposures to the risk of amyotrophic lateral sclerosis (ALS) among military veterans.
Occupational histories for 1597 study participants collected as part of the GENEVA study were the basis for this retrospective exposure assessment. The data set included 15528 jobs held from 1924 to 2010, representing 4539 unique industry and occupation (I&O) combinations. Three industrial hygiene experts were recruited to independently rate occupational exposures to specific agents previously associated with an increased risk of ALS. Utilizing information on industry, job title, tasks performed, and materials used for each job held, raters assigned exposures associated with each I&O for the 'current time' defined as the period after 1995 (post-1995). The exposure assessment targeted agents identified as potential occupational risk factors for ALS. Experts rated semi-quantitatively exposure intensity in five exposure categories (0-4) for Group A agents (lead, formaldehyde, hydrocarbon solvents, and chlorinated solvents) and qualitatively as yes/no (1/0) exposed for Group B agents (mercury, selenium, arsenic, polychlorinated biphenyls, electromagnetic field, pesticides, and viral agents). Confidence scores (0-3) were reported for every I&O rated based on raters' experience with that industry and/or job. Each I&O was assigned an average exposure score of the raters and an alternative exposure rating was developed for each I&O by excluding low confidence (<2) scores before averaging. Exposure reconstruction for jobs held pre-1995 was done by comparing exposure data extracted from the OSHA Chemical Exposure and Health Database (CEHD) during pre-1995 and post-1995. For agents with limited exposure data in the CEHD, pre-1995 exposures were determined based on raters' judgment.
The proportion of I&O combinations determined to be 'exposed' ranged from 0.1 to 26% across different agents, with the highest values corresponding to hydrocarbon solvents and the lowest to selenium. Industries with the highest proportion of exposed records include manufacturing, utilities, healthcare, and military with non-combat jobs. Analyses for raters' reliability showed the best agreement between the raters when rating exposure to viral agents (kappa = 0.67), hydrocarbon solvents (kappa = 0.53), and lead (kappa = 0.50). The proportion of 'exposed' I&O combinations increased for hydrocarbon solvents, chlorinated solvents, and pesticides when exposure ratings were adjusted by raters' confidence. Compared to post-1995, exposures in the earlier period (pre-1995) were deemed higher or the same for most of the agents and lower for formaldehyde and electromagnetic field exposures.
Our results indicate that using raters' confidence assessment in determining exposure scores increases both the proportion of I&O combinations regarded as exposed and the intensity scores, suggesting raters tend to be conservative in their assessment when they lack detailed knowledge of an industry or job.
本文描述了基因与环境暴露退伍军人研究（GENEVA）中进行的回顾性暴露评估，该研究是一项病例对照研究，旨在调查遗传因素和环境暴露因素共同作用对退伍军人肌萎缩侧索硬化症（ALS）发病风险的影响。
本研究的回顾性暴露评估以 GENEVA 研究中收集的 1597 名研究参与者的职业史为基础。该数据集包括 1924 年至 2010 年期间从事的 15528 项工作，代表 4539 种独特的工业和职业（I&O）组合。招募了三名工业卫生专家，对先前与 ALS 风险增加相关的特定代理的职业暴露进行独立评估。利用每个职业的行业、职称、任务和使用的材料信息，评估员为每个 I&O 分配了与“当前时间”（定义为 1995 年后）相关的暴露，当前时间指的是 1995 年之后的时期。暴露评估针对的是被确定为 ALS 潜在职业风险因素的试剂。专家们对 A 组试剂（铅、甲醛、碳氢化合物溶剂和氯化溶剂）的暴露强度进行了半定量评估，分为五个暴露类别（0-4），对 B 组试剂（汞、硒、砷、多氯联苯、电磁场、杀虫剂和病毒剂）则定性评估为是/否（1/0）暴露。根据评估员对该行业和/或工作的经验，为每个被评估的 I&O 报告了置信度评分（0-3）。每个 I&O 都被分配了评估员的平均暴露评分，并且通过在平均之前排除低置信度（<2）评分来为每个 I&O 开发替代暴露评分。1995 年之前工作的暴露重建是通过比较从 OSHA 化学暴露和健康数据库（CEHD）中提取的暴露数据来完成的，CEHD 中的暴露数据为 1995 年之前和 1995 年之后。对于 CEHD 中暴露数据有限的试剂，根据评估员的判断确定 1995 年之前的暴露情况。
不同试剂的“暴露”I&O 组合比例从 0.1%到 26%不等，最高值对应于碳氢化合物溶剂，最低值对应于硒。暴露记录比例最高的行业包括制造业、公用事业、医疗保健和军队（非战斗岗位）。对评估员可靠性的分析表明，当评估员对病毒剂（kappa = 0.67）、碳氢化合物溶剂（kappa = 0.53）和铅（kappa = 0.50）的暴露进行评分时，评估员之间的一致性最佳。当根据评估员的置信度调整暴露评分时，碳氢化合物溶剂、氯化溶剂和杀虫剂的“暴露”I&O 组合比例增加。与 1995 年后相比，大多数试剂的早期（1995 年前）暴露被认为更高或相同，而甲醛和电磁场暴露则较低。
我们的结果表明，在确定暴露评分时使用评估员的置信度评估会增加被认为暴露的 I&O 组合的比例和强度评分，这表明评估员在缺乏对行业或工作的详细了解时，在评估时往往会持保守态度。
