Visual evoked potentials in individuals exposed to long-term low concentrations of toluene

Abstract

An investigation of visual evoked potentials was carried out in two groups of subjects; 49 workers employed in a printing-prss where toluene has been used exclusively as an organic solvent for the last 30 years, and 59 workers not occupationally exposed to any known neurotoxic substances. The average length of work service in the printing-press was 21.4 years. The level of exposure was assessed by determination of the concentration of toluene in peripheral blood, the concentration of hippuric acid and ortho-cresol in urine in subgroups of subjects chosen at random from both groups. N75, P100 and N145 waves of the pattern reversal visual evoked potentials were analyzed. In the group of exposed subjects, significantly greater amplitudes were found in all waves, with significantly longer latency of the P100 wave.

Biological monitoring of controlled toluene exposure

“…This observation was con®rmed by comparison of measured blood levels ( Fig. 3) with average background concentrations of 3±16 nmol/l [6,11,12,22,25,59,71]. In contrast, background levels of hippuric acid and p-cresol were prominent throughout the pre-and postexposure periods (Figs.…”

Effect of Chronic and Subchronic Organic Solvents Exposure on Balance Control of Workers in Plant Manufacturing Adhesive Materials

“…Several studies have shown significant adverse health effects, predominantly in the CNS in workers after chronic exposure to toluene in the range of 157-251 mg/m 3 on color vision, auditory evoked brain potentials and neurobehavioral parameters (Foo et al 1990;Abbate et al 1993;Vrca et al 1995;Boey et al 1997;Eller et al 1999;Gericke et al 2001). Few studies have been conducted to understand the effect of low doses of toluene for a long duration (Soulage et al 2004), especially the additive neurotoxic effects due to a subchronic exposure on balance control.…”

HETA 2000-0110-2849, Human Performance International, Inc., Charlotte, North Carolina.

“…37,38 Studies conducted with printing workers reported that toluene exposure has been associated with evoked auditory potential abnormalities and increased prevalences of audiometric hearing loss. 39,40,41,42 Biological determinants of toluene, in blood 40 or urine, 42 were found to be associated with the auditory outcomes (i.e., elevated auditory thresholds with increased toluene levels).…”