Biological monitoring of exposure to styrene by analysis of combined urinary mandelic and phenylglyoxylic acids

Abstract

Human volunteers were exposed in an experimental chamber to styrene (environmental pollutant, 4 or 8 h at 40-200 ppm) to obtain a quantitative relationship between exposure and urinary elimination of the metabolites mandelic and phenylglyoxylic acids (MA and PGA). For the analysis of PGA a new GC[gas chromatographic]-method was used, based on reductive transformation of the relatively instable PGA into MA, which is stable enough for shipping and handling until final processing. The analysis of the post-exposure elimination shows that spot urine sampled in the morning after exposure and analysed for the sum of MA and PGA is the most reliable index for reflecting a preceding exposure to styrene.