title: Amyotrophic lateral sclerosis and agricultural environments: a systematic review.
abstract: The aim of this study was to examine the relationship between the risk of amyotrophic lateral sclerosis (ALS) and exposure to rural environments. Studies were identified through OVID MEDLINE and EMBASE search up to September 2013 using as keywords rural residence, farmers, and pesticide exposure. Twenty-two studies were included for this meta-analysis. Summary odds ratios (ORs) were calculated using random effect model by type of exposure index, and subgroup analyses were conducted according to study design, gender, region, case ascertainment, and exposure assessment. The risk of ALS was significantly increased with pesticide exposure (OR, 1.44; 95% CI, 1.22-1.70) and with farmers (OR, 1.42; 95% CI, 1.17-1.73), but was not significant with rural residence (OR, 1.25; 95% CI, 0.84-1.87). The risk estimates for subgroup analysis between pesticide exposure and ALS indicated a significant positive association with men (OR, 1.96), and in studies using El Escorial criteria for ALS definition (OR, 1.63) and expert judgment for pesticide exposure (OR, 2.04) as well. No significant publication bias was observed. Our findings support the association of pesticide exposure and an increased risk for ALS, stressing that the use of more specific exposure information resulted in more significant associations.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Hyun
authors.identifier: 0000-0003-2844-5880
authors.initials: H
authors.lastname: Kang
authors.affiliation: Department of Preventive Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Eun Shil
authors.identifier: 0000-0001-5059-5776
authors.initials: ES
authors.lastname: Cha
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Geun Joo
authors.identifier: 0000-0002-4653-4193
authors.initials: GJ
authors.lastname: Choi
authors.affiliation: Department of Preventive Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Won Jin
authors.identifier: 0000-0002-0254-7267
authors.initials: WJ
authors.lastname: Lee
mesh_terms: D017677:Age Distribution; D000383:Agriculture / Q000706:statistics & numerical data*; D000690:Amyotrophic Lateral Sclerosis / Q000453:epidemiology*; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009784:Occupational Diseases / Q000453:epidemiology*; D010575:Pesticides / Q000032:analysis*; D016016:Proportional Hazards Models; D012307:Risk Factors; D017678:Sex Distribution
chemical_list: D010575:Pesticides
keywords: Agriculture; Environmental Exposure; Farming; Meta-analysis; Neurodegenerative Diseases; Occupations