Abstract:
The objective of this study was to assess acute effects caused by occupational
solvent exposures at the level of the MAC value (maximum allowable concentration)
on nervous functions. Postural sway was measured and four tests of the
Neuropsychological Evaluation System (NES2: Symbol Digit, Pattern Memory,
Digit Span, Switching Attention) were administered to 23 male foundry workers
at the end of a working shift. Personal exposures to isopropanol were measured
by passive sampling and exposures to methylformate by active sampling and
by urinary methanol. Environmental concentrations were monitored by Fourier
Transformation InfraRed Spectrometry (FTIR). As controls 8 skilled and
15 unskilled workers from the printing industry performed the same tests
and underwent the same measurement procedures as did the foundry workers.
Personal exposures in the foundry ranged from 22 ppm to 136 ppm (median
68 ppm) for methylformate and from 6 ppm to 73 ppm (median 28 ppm) for
isopropanol. Skilled printers couldn’t be compared to the other two groups
because of their longer education and significantly younger age. There
were no significant differences in test performance between unskilled printers
and foundry workers. With respect to the foundry workers, personal solvent
dose correlated significantly with several neurobehavioral functions: lateral
sway in monopedal and bipedal standing significantly correlated with the
isopropanol dose of the same day. Higher personal exposures to isopropanol
significantly correlated with poorer short-term memory (Digit Span and
Pattern Memory). This study indicates that sub-MAC exposures to the solvent
isopropanol together with methylformate may affect nervous functions. The
results are based on a small sample and further investigations regarding
these two solvents are recommended.
| Received: 10 June 1998
Accepted: 10 December 1998 Posted: 2 March 1999 |
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