ASSESSMENT OF LONG-TERM STYRENE EXPOSURE - A COMPARATIVE-STUDY OF A LOGBOOK METHOD AND BIOLOGICAL MONITORING

In a recent joint European research project ''Biomonitoring of human p opulations exposed to genotoxic environmental chemicals: biomonitoring of styrene exposed individuals'', a logbook method for assessment of long-term styrene exposure was applied in two Danish factories manufac turing glass fibre-reinforced polyester. The method was based on work process identification, assignment of work process concentrations and logbook keeping. Measures of exposure calculated by this method were c ompared with results from simultaneous measurements of styrene in bloo d and the metabolites mandelic acid and phenylglyoxylic acid in urine. Correlations were comparable with those obtained by use of personal s amplers as published in the literature. Styrene in blood, however, onl y correlated with logbook concentrations at the time of sampling. Expo sures were moderate to low. Mean personal 8-h time-weighted average co ncentration (8hTWAC) was 76 mg/m(3) styrene (SD 54 mg/m(3), range 2-23 0 mg/m(3)). The Danish 8hTWAC threshold limit value for styrene in air , 105 mg/m(3) (25 ppm), was exceeded on 17% of personal days. The summ ed urinary metabolites, mandelic acid and phenylglyoxylic acid, had a mean personal value of 138 mg/g creatinine (SD 84 mg/g creatinine) on the day of sampling. Blood styrene mean value was 129 mu g/1 (SD 74 mu g/1, range 66-358 mu g/1). It is concluded that the logbook method of fers a technique for testing whether measurements are performed on rep resentative days and may be recommended as a tool supplementary to bio logical monitoring in the assessment of long-term exposure.