Multicenter field trial on possible health effects of toluene. I. Toluene body burdens in workers of the rotogravure industry

Abstract

Ambient air toluene concentrations as well as corresponding individual blood toluene levels were measured under conditions of a field trial, as basis for a correlation with possible acute effects. While the results of various psycho-physiological and medical evaluations after acute (Neubert et al., 2001) and long-term toluene exposure (Gericke et al., 2001) are published in accompanying papers, this publication deals with the exposure levels and body burdens characteristic of workers in the rotogravure industry in Germany at the time of the investigation (1993-1995). Besides providing some information on the exposure at various work-areas under occupational conditions, the correlation between a time-weighted average of the ambient air concentration with the corresponding blood toluene levels is analyzed. Limitations of such an attempt and possible pitfalls are discussed. In the largest field study so far performed on toluene exposure, 12 companies of the German rotogravure industry (and a total of 1528 volunteers) participated. Altogether, complete data sets, i.e. on both ambient air as well as blood toluene levels, were obtained from 1244 male and 124 female participants of the rotogravure industry with quite different degrees of toluene exposure. Rotogravure printers and their helpers were exposed to the highest toluene concentrations in ambient air. On the day of the evaluation, of 806 male volunteers within this group (of 1261 with verified exposure in air), 35 were exposed to a time-weighted average of 100 ppm (i.e. 375 mg/m(3)) or above, and 155 of the printers to concentrations between 50 and 100 ppm. Of the remaining 455 male participants of the rotogravure factories ('non-printers and helpers'), only three were exposed to toluene concentrations above 50 ppm. Only one of the 124 women working in the rotogravure factories was exposed to an average toluene concentrations above 100 mg/m(3) (i.e. 27 ppm). In 66 of the male volunteers toluene levels in blood of >850 microg/l were measured and 14 showed levels exceeding 1700 microg/l. When attempting to predict the resulting individual blood toluene levels from measurements of ambient air concentrations under field conditions, a considerable uncertainty is to be expected. We found a correlation coefficient of the regression curve of about 0.70, with numerous outliers (and a variation of the 12 factories between 0.52 and 0.88).