Changes of neurobehavioral and sensory functions due to toluene exposure below 50ppm?

Data of a follow up study with four examinations were summarized by odds ratio statistics in order to scrutinize the results of the earlier studies with cross sectional approaches. For a "high"- (n=106) and a "low"-exposed group (references, n=86) current toluene exposures of 26ppm versus 3ppm and lifetime weighted average exposures of 45ppm versus 9ppm were ascertained. As measures of sensory functions vibration thresholds, colour discrimination, and auditory thresholds were used. Measures of psychological performances were attention (symbol-digit substitution, switching attention, simple reaction), memory (digit span forward, delayed reproduction of pictures), and psychomotor functions (steadiness, line tracing, aiming, tapping, peg board). Additionally, the frequency of diseases and symptoms were ascertained. By odds ratio statistics including relevant cofactors no significant increase of "cases with impaired functions" among the high-exposed workers was found. Evidence for neurobehavioral effects due to long-term toluene exposure below 50ppm was not established.