The neurobehavioral toxicity of trichloroethylene.

Trichloroethylene is an industrial solvent used primarily in degreasing operations with some use as an anesthetic agent as well. The primary route of exposure is inhalation and the central nervous system effects consist of headache, nausea, sleepiness, burning of the eyes. Human cases of intoxication have been associated with trigeminal neuropathy, however this is probably caused by a breakdown product dichloroacetylene. Fatal exposures may be the result of cardiac failure. Chronic exposure in industrial settings may cause alterations in a variety of behavioral parameters such as reduced memory and intellectual functioning. Experimental human exposures reveal fatigue and sleepiness effects and possible alterations in reaction time, but no deterioration in performance on manual dexterity tasks up to 300 ppm exposures. Animal experiments using acute exposures generally fail to reveal behavioral effects at concentrations below 1000 ppm, with a range of 75-2000 ppm. Cessation of exposure results in rapid behavioral recovery with no residual behavioral deficits. Exposure of dogs to 3000 ppm chronically results in severe cerebellar pathology, with no trigeminal nerve damage. No neurochemical effects of exposure have been documented. The neurobehavioral literature on the toxic effects of trichloroethylene is fragmented and poorly documented suggesting that more and better quality work is needed to understand the potential toxicity of this compound.