title: Time may not fully attenuate solvent-associated cognitive deficits in highly exposed workers.
abstract: OBJECTIVE
  To test the effects of lifetime occupational solvent exposure, as measured by dose and timing, on performance on multiple cognitive tests among retired French utility workers.
  
  
  METHODS
  A total of 2,143 retirees in the GAZEL cohort underwent cognitive testing in 2010. Lifetime exposure to chlorinated solvents, petroleum solvents, and benzene was assessed using a job exposure matrix. We modeled effects of lifetime solvent dose, timing of last exposure, and a combination of these metrics on risk for cognitive impairment.
  
  
  RESULTS
  Thirty-three percent of participants were exposed to chlorinated solvents, 26% to benzene, and 25% to petroleum solvents. High exposure to solvents was significantly associated with poor cognition; for example, those highly exposed to chlorinated solvents were at risk of impairment on the Mini-Mental State Examination (risk ratio 1.18; 95% confidence interval 1.06, 1.31), the Digit Symbol Substitution Test (1.54; 1.31, 1.82), semantic fluency test (1.33; 1.14, 1.55), and the Trail Making Test B (1.49; 1.25, 1.77). Retirees at greatest risk for deficits had both high lifetime exposure to solvents and were last exposed 12 to 30 years before testing. Risk was somewhat elevated among those with high lifetime exposure who were last exposed 31 to 50 years before testing. Those with high, recent exposure exhibited impairment in almost all domains, including those not typically associated with solvent exposure.
  
  
  CONCLUSIONS
  While risk of cognitive impairment among moderately exposed workers may attenuate with time, this may not be fully true for those with higher exposure. This has implications for physicians working with formerly solvent-exposed patients as well as for workplace exposure limit policies.
authors.affiliation: From the Harvard Center for Population and Development Studies (E.L.S.), Cambridge, MA; INSERM U1061 (L.-A.G., C.B.), Neuropsychiatrie: recherche épidemiologique et clinique, Université Montpellier I, Hôpital La Colombière, France; Department of Society, Human Development, and Health (C.A.O.), Harvard School of Public Health, Boston, MA; INSERM U1018 (A.S.-M.), Centre for Research in Epidemiology and Population Health, AP-HP; University of Bordeaux (H.A.), ISPED, Centre INSERM U897-Epidemiologie-Biostatistique; University of Bordeaux (H.A.), Department of Psychology, Bordeaux; Population-based Cohort Platform (M.G., M.Z.), Epidemiology and Public Health Research Center, UMRS INSERM 1018, Villejuif; Université Versailles Saint-Quentin UMRS 1018 (M.G., M.Z.); CMRR Languedoc Roussillon (C.B.), CHU Montpellier, France.
authors.forename: Erika L
authors.initials: EL
authors.lastname: Sabbath
authors.forename: Laure-Anne
authors.initials: LA
authors.lastname: Gutierrez
authors.forename: Cassandra A
authors.initials: CA
authors.lastname: Okechukwu
authors.forename: Archana
authors.initials: A
authors.lastname: Singh-Manoux
authors.forename: Hélène
authors.initials: H
authors.lastname: Amieva
authors.forename: Marcel
authors.initials: M
authors.lastname: Goldberg
authors.forename: Marie
authors.initials: M
authors.lastname: Zins
authors.forename: Claudine
authors.initials: C
authors.lastname: Berr
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000139:chemically induced* / Q000453:epidemiology; D005602:France / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009483:Neuropsychological Tests; D016273:Occupational Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D012997:Solvents / Q000633:toxicity*; D013997:Time Factors
chemical_list: D012997:Solvents