title: Occupational solvent exposure and brain function: an fMRI study.
abstract: BACKGROUND
  Deficits in cognitive function have been demonstrated among workers chronically exposed to solvents, but the neural basis for these deficits has not been shown.
  
  
  OBJECTIVE
  We used functional magnetic resonance imaging (fMRI) to compare pathophysiological changes in brain function between solvent-exposed and control workers.
  
  
  METHODS
  Painters, drywall tapers, and carpenters were recruited from the International Union of Painters and Allied Trades, District Council 9 in New York City and District Council 21 in Philadelphia, Pennsylvania, and from the Carpenters Union in New Jersey. Twenty-seven solvent-exposed and 27 control subjects of similar age, education, and occupational status completed the N-Back working memory test during fMRI. After controlling for confounders (age; lifetime marijuana, cocaine, and alcohol use; blood lead; symptoms of depression; verbal intelligence), voxelwise group analysis and regional activation levels were compared and then correlated with an index of lifetime solvent exposure.
  
  
  RESULTS
  Solvent-exposed workers' performance on the N-Back was significantly worse than that of controls. Activation of the anterior cingulate, prefrontal, and parietal cortices--areas serving working memory function and attention--was also significantly lower for solvent-exposed workers relative to controls. After controlling for confounders, we observed a negative correlation between lifetime solvent exposure and activation in these same regions among the solvent-exposed workers.
  
  
  CONCLUSIONS
  This study is one of the few to document neural structures affected by exposure to solvents. Our findings provide a biological mechanism for the neurobehavioral deficits in working memory and attention that have previously been reported by other groups studying the effects of chronic exposure to solvents. These imaging markers, which are consistent with the neurobehavioral measures in our subject population, are consistent with altered brain pathology caused by prolonged exposure to solvent mixtures during construction work.
authors.affiliation: Department of Radiology, Mount Sinai School of Medicine, New York, New York 10029, USA. Cheuk.Tang@mssm.edu
authors.forename: Cheuk Ying
authors.initials: CY
authors.lastname: Tang
authors.forename: David M
authors.initials: DM
authors.lastname: Carpenter
authors.forename: Emily L
authors.initials: EL
authors.lastname: Eaves
authors.forename: Johnny
authors.initials: J
authors.lastname: Ng
authors.forename: Nimalya
authors.initials: N
authors.lastname: Ganeshalingam
authors.forename: Clifford
authors.initials: C
authors.lastname: Weisel
authors.forename: Hua
authors.initials: H
authors.lastname: Qian
authors.forename: Gudrun
authors.initials: G
authors.lastname: Lange
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Fiedler
mesh_terms: D000328:Adult; D001288:Attention; D001921:Brain / Q000503:physiopathology*; D001927:Brain Diseases / Q000139:chemically induced / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D008570:Memory, Short-Term; D008875:Middle Aged; D009515:New Jersey / Q000453:epidemiology; D009519:New York City / Q000453:epidemiology; D009784:Occupational Diseases / Q000139:chemically induced / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D016273:Occupational Exposure; D015143:Philadelphia / Q000453:epidemiology; D012997:Solvents / Q000009:adverse effects*
chemical_list: D012997:Solvents