Neurobehavioral Effects of Low Level Solvent Exposures in a Foundry

Tanja Sethre, Thomas Läubli, Michael Riediker, Markus Hangartner, Helmut Krueger

Institute for Hygiene and Applied Physiology, Federal Institute of Technology Zurich, Switzerland
 
Corresponding author: Tanja Sethre
Clausiusstr. 25
CH-8092 Zürich
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e-mail: sethre@iha.bepr.ethz.ch



Keywords:
Isopropanol, methylformate, neurobehavioral effects, occupational exposure, solvents

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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