title: Pesticide exposure and amyotrophic lateral sclerosis.
abstract: Our objectives were to summarize literature on the association of amyotrophic lateral sclerosis (ALS) with pesticides as a group and to evaluate associations of ALS with specific pesticides. We conducted a meta-analysis of published studies of ALS and pesticides as a group and investigated the association of ALS with specific pesticides, using data from the Agricultural Health Study (AHS), a cohort including 84,739 private pesticide applicators and spouses. AHS participants provided information on pesticide use at enrollment in 1993-1997. In mortality data collected through February 2010, ALS was recorded on death certificates of 41 individuals whom we compared to the remaining cohort (controls), using unconditional logistic regression adjusted for age and gender to calculate odds ratios (ORs) and 95% confidence intervals. In the meta-analysis, ALS was associated with use of pesticides as a group (1.9, 1.1-3.1). In the AHS, ALS was not associated with pesticides as a group, but was associated with use of organochlorine insecticides (OCs) (1.6, 0.8-3.5), pyrethroids (1.4, 0.6-3.4), herbicides (1.6, 0.7-3.7), and fumigants (1.8, 0.8-3.9). ORs were elevated forever use of the specific OCs aldrin (2.1, 0.8-5.1), dieldrin (2.6, 0.9-7.3), DDT (2.1, 0.9-5.0), and toxaphene (2.0, 0.8-4.9). None of these associations was statistically significant. Similar results were observed in an analysis restricted to men. In conclusion, the meta-analysis suggests that ALS risk is associated with use of pesticides as a group, and our analysis of AHS data points to OC use in particular. The latter results are novel but based on a small number of cases and require replication in other populations.
authors.affiliation: Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA. kamel@niehs.nih.gov
authors.forename: Freya
authors.initials: F
authors.lastname: Kamel
authors.forename: David M
authors.initials: DM
authors.lastname: Umbach
authors.forename: Richard S
authors.initials: RS
authors.lastname: Bedlack
authors.forename: Marie
authors.initials: M
authors.lastname: Richards
authors.forename: Mary
authors.initials: M
authors.lastname: Watson
authors.forename: Michael C R
authors.initials: MC
authors.lastname: Alavanja
authors.forename: Aaron
authors.initials: A
authors.lastname: Blair
authors.forename: Jane A
authors.initials: JA
authors.lastname: Hoppin
authors.forename: Silke
authors.initials: S
authors.lastname: Schmidt
authors.forename: Dale P
authors.initials: DP
authors.lastname: Sandler
mesh_terms: D000367:Age Factors; D000368:Aged; D000382:Agricultural Workers' Diseases / Q000139:chemically induced* / Q000401:mortality; D000383:Agriculture; D000690:Amyotrophic Lateral Sclerosis / Q000139:chemically induced* / Q000401:mortality; D005260:Female; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000009:adverse effects*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D016017:Odds Ratio; D010575:Pesticides / Q000009:adverse effects*; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D018454:Spouses
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides