Supplementary Material for: Environmental and Occupational Risk Factors for Amyotrophic Lateral Sclerosis: A Case-Control Study

<b><i>Background/Aims:</i></b> Environmental and occupational exposures are implicated as risk factors for amyotrophic lateral sclerosis (ALS), the etiology of which is largely unknown, although no causal relationships have been established. <b><i>Objective:</i></b> The aim of the study was to evaluate the associations of personal risk factors and self-reported environmental and occupational exposures with risk of ALS. <b><i>Methods:</i></b> The cases involved ALS patients (n = 66) identified from major neurological centers in Pittsburgh and Philadelphia, Pa., USA, from 2008 to 2010. The age-, race- and sex-matched controls included outpatient hospital and population-based controls (n = 66). A detailed questionnaire obtaining data on occupation, vocational and avocational exposure as well as personal lifestyle factors was administered. <b><i>Results:</i></b> Occupational exposure to metals (odds ratio, OR = 3.65; 95% CI: 1.15, 11.60) and pesticides (OR = 6.50; 95% CI: 1.78, 23.77) was related to increased risk of ALS after controlling for smoking and education. No associations were found for occupational exposure to organic or aromatic solvents. <b><i>Conclusion:</i></b> Workers exposed to metals and pesticides may be at greater risk of ALS. Future research should involve more accurate exposure assessment through the use of job exposure matrices, confirmation of occupation and biomarkers.

**背景与目的：** 环境与职业暴露被认为是肌萎缩侧索硬化症（amyotrophic lateral sclerosis, ALS）的潜在危险因素，该病的病因学目前尚未明确，且尚未确立明确的因果关联。**目的：** 本研究旨在探讨个体危险因素、自我报告的环境与职业暴露与ALS发病风险的相关性。**方法：** 病例组为2008年至2010年间，从美国宾夕法尼亚州匹兹堡与费城的主要神经科中心招募并确诊的ALS患者（n=66）。对照组采用年龄、种族与性别匹配的门诊患者对照及人群对照（n=66）。研究通过详细问卷收集职业、职业性与业余休闲暴露情况及个人生活方式相关数据。**结果：** 在校正吸烟与教育水平等混杂因素后，职业性金属暴露（比值比（odds ratio, OR）=3.65；95%置信区间（confidence interval, CI）：1.15, 11.60）与农药暴露（OR=6.50；95%CI：1.78, 23.77）与ALS发病风险升高显著相关。未发现职业性有机或芳香族溶剂暴露与ALS存在统计学关联。**结论：** 接触金属与农药的职业人群罹患ALS的风险可能更高。未来研究应借助职业暴露矩阵（job exposure matrices）、职业史确认及生物标志物（biomarkers）检测，实现更精准的暴露评估。