E-Mail karger@karger.com Original Paper Neurodegener Dis DOI: 10.1159/000355344 Environmental and Occupational Risk Factors for Amyotrophic Lateral Sclerosis: A Case-Control Study Angela M. Malek   a Aaron Barchowsky   b Robert Bowser   f Terry Heiman-Patterson   g David Lacomis   e Sandeep Rana   g Ada Youk   c David Stickler   a Daniel T. Lackland   a Evelyn O. Talbott   d a  Department of Neurosciences, College of Medicine, Medical University of South Carolina, Charleston, S.C., Departments of b  Environmental and Occupational Health, c  Biostatistics and Epidemiology and d  Epidemiology, Graduate School of Public Health, University of Pittsburgh, and e  Departments of Neurology and Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pa., f  Departments of Neurology and Neurobiology, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, Ariz., and g  Department of Neurology, College of Medicine, Drexel University, Philadelphia, Pa., USA 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 edu- cation. No associations were found for occupational expo- sure to organic or aromatic solvents. Conclusion: 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, con- firmation of occupation and biomarkers. © 2013 S. Karger AG, Basel Introduction Background The annual global incidence of amyotrophic lateral sclerosis (ALS) is approximately 1–2.6 per 100,000 per- sons [1]. Male sex, older age and genetic alterations, such Key Words Amyotrophic lateral sclerosis · Epidemiology · Environmental exposure · Occupational exposure · Risk factors Abstract Background/Aims: Environmental and occupational expo- sures are implicated as risk factors for amyotrophic lateral sclerosis (ALS), the etiology of which is largely unknown, al- though no causal relationships have been established. Ob- jective: 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. Methods: The cases involved ALS patients (n = 66) identified from major neuro- logical centers in Pittsburgh and Philadelphia, Pa., USA, from 2008 to 2010. The age-, race- and sex-matched controls in- cluded outpatient hospital and population-based controls (n = 66). A detailed questionnaire obtaining data on occupa- tion, vocational and avocational exposure as well as person- al lifestyle factors was administered. Results: Occupational Received: January 22, 2013 Accepted after revision: August 27, 2013 Published online: November 12, 2013 Diseases Angela M. Malek, PhD, MPH Department of Neurosciences, College of Medicine Medical University of South Carolina Suite 501, 19 Hagood Avenue, Charleston, SC 29425 (USA) E-Mail malek  @  musc.edu © 2013 S. Karger AG, Basel 1660–2854/13/0000–0000$38.00/0 www.karger.com/ndd The study was conducted at the University of Pittsburgh. Downloaded by: Rowland Medical Library 192.231.71.2 - 11/21/2013 6:53:06 PM