A survey was conducted in the second half of a working week on 33 women who either applied glue (with cyclohexane as an almost exclusive solvent component) or worked in the vicinity of glue application. Carbon cloth-equipped diffusive samplers were used for personal measurement of time-weighted average intensity of exposure to the solvent. The geometric mean and the highest cyclohexane concentration observed in air were 27 ppm and 274 ppm, respectively. Concentrations of cyclohexanol in urine samples and cyclohexane in whole blood and serum collected at the end of a shift showed significant correlations with the solvent exposure levels. Urinary cyclohexanone also correlated, but with a smaller correlation coefficient. The observation suggests that cyclohexanol in urine and cyclohexane in blood or serum collected at the end of a shift are useful indicators of occupational exposure to cyclohexane vapor. Quantitative estimation of balance at the end of the shift suggested that only a minute portion (< 1%) of cyclohexane absorbed is excreted in the urine as cyclohexanol, almost exclusively as a glucuronide. A survey of subjective symptoms revealed an increase in the prevalence of "dimmed vision " and "unusual smell", but hematology and serum biochemistry testing did not indicate any specific signs.

Objectives-To survey the loss of colour vision among Japanese workers who have been exposed to styrene concentrations currently considered low (about 20 ppm). Also to assess the effects of styrene by examination of the nature of the relation between disorder of colour vision and age, alcohol consumption, and other variables. Methods-Colour discrimination was examined in 64 male workers exposed to styrene (mean age; 38'0, mean exposed years; 7'0) and in 69 controls (mean age; 38.0). A standardised questionnaire was adopted to collect work history, occupational or non-occupational solvent exposure, alcohol consumption, and drug use. The results of the test were expressed as the colour confusion index (CCI). Results-The mean atmospheric styrene concentration was about 20 ppm. The mean urinary concentration of mandelic acid was 0-22 gil. There was a significant difference in CCI between exposed workers and age matched controls. Colour vision of workers whose concentration of urinary mandelic acid was > 0'42 gil was significantly impaired when compared with workers whose concentration was <0'42 gil. Multiple linear regression analysis that controlled confounding variables such as age, alcohol consumption, smoking, and educational attainment showed that the CCI was significantly related to the concentration of urinary mandelic acid. In both exposed workers and controls, the types of defects were mostly blue-yellow loss, although a few subjects showed complex loss. No one showed only red-green loss.Conclusions-These findings suggest that exposure to moderate styrene concentrations can lead to impairment of colour vision, and that there is a significant correlation with the urinary metabolite of styrene.(Occup Environ Med 1995;52:534-538)

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Objectives-To examine the effect of occupational exposure to cyclohexane on the peripheral nervous system. Methods-A nerve conduction study was performed on 18 workers exposed to cyclohexane in a luggage factory and on age and sex matched occupationally unexposed controls. 12 workers had been exposed to n-hexane (median 2-8 years) before the start of exposure to cyclohexane. To confirm the effect of exposure, a follow up study was performed on nine workers one year after the first study. The mean exposure to cyclohexane was 1 2 years in the first study. A symptom survey was performed. The exposure was measured by air sampling of the breathing zone of each worker. The urinary metabolite cyclohexanol was also monitored. Results-The concentration of airborne cyclohexane ranged from 5 to 211 ppm. The urinary concentration of cyclohexanol ranged from 0-12 to 1 51 mg/I. There was a strong correlation between the cyclohexane exposure in personal air and urinary cyclohexanol. No differences were found in nerve conduction velocities (NCV) between workers exposed to cylohexane and age and sex matched controls. The results of the follow up study showed significant improvements in peroneal motor NCV (P < 0.01) and sural sensory NCV (P < 005) and in ulnar motor distal latency (MDL, P < 005) and peroneal MDL (P < 005) compared with the first study. Although the past n-hexane exposure affected the first neurophysiological study, the effect had disappeared in the second study, one year later. Conclusion-Occupational exposure to the concentrations of cyclohexane experianced in this study had no adverse effects on the peripheral nervous system. (Occup Environ Med 1996;53:174-179)

The relationship between exposure to styrene and nerve conduction velocities was investigated in 32 workers occupationally exposed to styrene. There was a dose‐dependent relationship between urinary mandelic acid and ulnar and peroneal motor distal latencies (MDLs). The ulnar and peroneal MDLs of subgroup B (urinary mandelic acid ≥250 mg/l) were significantly longer than those of subgroup A (urinary mandelic acid <250 mg/l) (p < 0.05), and the referent group (p < 0.03). After adjusting confounding factors, urinary mandelic acid had a significant positive relationship with ulnar and peroneal MDL. Our study suggests that a low level of styrene, below the 50 ppm exposure limit of the American Conference of Governmental Industrial Hygienists (ACGIH), involves the risk of inducing adverse effects on the peripheral nervous system. The study also indicated that motor distal latency is a sensitive parameter of toxic peripheral neuropathy. © 1996 Wiley‐Liss, Inc.