Decades Old Solvent Exposure May Cause Cognitive Problems

HealthDay News — Time may not fully mitigate solvent-associated cognitive deficits in highly-exposed workers, according to researchers.

Erika L. Sabbath, ScD, from the Harvard Center for Population and Development Studies in Cambridge, Mass., and colleagues analyzed cognitive testing results from 2,143 retirees in the GAZEL cohort. A job exposure matrix was used to assess lifetime exposure to chlorinated solvents, petroleum solvents, and benzene. The findings were published in Neurology.

The researchers found that 33% of participants were exposed to chlorinated solvents, 26% to benzene, and 25% to petroleum solvents. There was a significant association between exposure to solvents and poor cognition.

Those with high exposure to chlorinated solvents were at risk of impairment on the Mini-Mental State Examination (risk ratio, 1.18), the Digit Symbol Substitution Test (1.54), semantic fluency test (1.33) and the Trail Making Test B (1.49).

Those with both high lifetime exposure to solvents and last exposure 12 to 30 years before testing were at greatest risk for deficits. For those with high lifetime exposure who were last exposed 31 to 50 years before testing, risk was somewhat elevated. Impairment in almost all domains, including those not typically associated with solvent exposure, was seen for those with high, recent exposure.

“While risk of cognitive impairment among moderately-exposed workers may attenuate with time, this may not be fully true for those with higher exposure,” the researchers wrote.


  1. Sabbath EL et al. Neurology. 2014; 82(19):1716-1723.