Neurophysiological effects of long-term exposure to hydrocarbon mixtures.

Motor nerve conduction velocity (MCV) was measured on median, ulnar and peroneal nerves in a reference group of 52 workers and a group of 95 workers exposed to hydrocarbon mixtures in a shoe factory. Exposure-related changes were found in motor action potential (MAP) amplitudes of the three nerves and in median and peroneal MCVs. Electroneurographic abnormalities were also present in a subgroup of workers exposed to air concentrations near the current ACGIH (1979) recommended threshold limit value (TLV) for the mixture. Our results suggest the need for lowering the TLV for the main components n-hexane and cyclohexane. A synergistic effect of the two hexacarbon solvent might also be considered in the hygienic evaluation of the workplace.