Dose-related cognitive deficits among floor layers with previous heavy exposure to solvents.

The authors used tests of attention and memory, which are sensitive to the influence of aging, to explore possible adverse effects on cognitive functioning following past heavy exposure to solvent-based glues, with special reference to dose-effect relationships and interactions with the aging process. The study included 41 floor layers and 40 carpenters (referents) who participated in a longitudinal follow-up assessment. The authors assessed cognitive functioning with the following tests: trail-making, color words, and word recall. Higher cumulative exposure was associated with poorer test performance that was related to concept shifting, episodic memory, and speed of congruent and incongruent color naming. The magnitude of the decrements in memory tasks was equivalent to about 20 yr of age-related decline. Dose-effect relationships were seen mainly for contact adhesives, and there was partial evidence for an interaction between exposure and aging.