Amyotrophic Lateral Sclerosis, Occupational Risk Factors and Exposure Windows: a Case-Control Study in Michigan

Background. Amyotrophic lateral sclerosis (ALS) is a progressive neuro-degenerative disease. Only 10% of ALS cases can be attributable to genetic mutations; causes for the remainder are unclear. Previous studies have identified several risk factors, but no factor has been consistently with ALS. This case-control study explores the role of occupational factors in the development of sporadic ALS. Methods. A total of 107 cases and 82 controls were recruited. Each completed a detailed questionnaire addressing residential and occupational history, demographics, smoking status, and physical activities, and provided biospecimens. Conditional logistic regression models for m:n matching on age and gender, and four exposure time windows (window=1: ever exposure; window=2: 0-10 years; window=3: 10-30 years; window= 4: = 30 years) investigated associations between risk factors and ALS. Results. CLR models identified several risk factors. Exposure to pesticides increased risk of ALS in all time windows (hazard ratios,...