Neurobehavioral effects of toluene: a review

Toluene appears to produce reversible effects upon liver, renal and nervous systems. Its usual route of intake is via respiration. The nervous system appears to be the most sensitive to the effects of toluene. Although there are few studies of toluene's neurotoxicity, some tenuous results can be cited. High level toluene exposures produced incoordination, ataxia, unconsciousness and eventually, death. Lower level acute exposures in man produce dizziness, exhilaration and confusion. Activity level has been inadequately studied. Schedule controlled behaviors have been reported to produce inverted U-shaped concentration-effect curves on response rate measures. Alterations at levels as low as 150 ppm have been reported when appetitive contingencies are used. Very few studies of the nervous system have been performed at levels below 1000 ppm and most of the results were inconclusive. The TLV (threshold limit value) of toluene has been set at 100 ppm for 8 hrs. No exposures on possible groups at special risk, such as perinatal, aged or impaired subjects have been made. Few studies of reversibility of effects in the nervous system have been reported. Much more work is needed before strong conclusions can be drawn.