Author Erika L. Sabbath said the findings were significant as workplace exposure to solvents was extremely common and posed a real risk both in the present and the future.
“And as retirement ages go up, the length of time that people are exposed is going up, too,” Dr Sabbath said.
Chlorinated solvents can be found in dry cleaning solutions, engine cleaners, paint removers and degreasers, while petroleum solvents are used in carpet glue, furniture polishes, paint, paint thinner and varnish.
Researchers assessed the lifetime exposure of 2143 retirees, as well as their last exposure to chlorinated solvents, petroleum solvents, and benzene, which is used in synthetics manufacturing.
Participants took eight memory and thinking skills tests 10 years after they had retired at an average age of 66.
Researchers found those with high and recent exposure at the greatest risk for memory and thinking deficits regardless of other factors, such as education levels, age, smoking and alcohol consumption.
Dr Sabbath, of the Harvard School of Public Health in Boston, said retirees with high exposure within the past 12 to 30 years had demonstrated impairment in virtually all areas of memory and thinking.
For more information about using solvents, visit the hazardous chemicals page.