ASSESSMENT OF OCCUPATIONAL EXPOSURE TO PAHS IN AN ESTONIAN COKE-OVEN PLANT - CORRELATION OF TOTAL EXTERNAL EXPOSURE TO INTERNAL DOSE MEASURED AS 1-HYDROXYPYRENE CONCENTRATION

The exposure of cokery workers to polynuclear aromatic hydrocarbons at an Estonian oil shale processing plant was assessed by using occupati onal hygiene and biomonitoring measurements which were carried out twi ce, in midwinter and in the autumn. To assess the external dose of pol ynuclear aromatic hydrocarbons, pyrene and benzo[a]pyrene concentratio ns were measured from the breathing zone of workers during a workshift . Skin contamination with pyrene and benzo[a]pyrene was assessed by sk in wipe sampling before and after the workshift. As a biomarker of ove rall exposure to polynuclear aromatic hydrocarbons, and as an integral of all absorption routes of pyrene, 1-hydroxypyrene concentration was measured from post shift urine samples, Of the personal air samples, 18% exceeded the Finnish threshold limit value of benzo[a]pyrene (10 m u g m(-3)). Mean value (two separate measurements together) for benzo[ a]pyrene was 5.7 mu g m(-3) and for pyrene, 8.1 mu g m(-3) Based on sk in wipe sample analyses, the skin contamination was also obvious. The mean value of benzo[a]pyrene in the samples collected after the shift was 1.2 ng cm(-2). Benzo[a]pyrene was not found in control samples, Th e mean value of urinary 1-hydroxypyrene concentration was 6.0 mu mol m ol(-1) creatinine for the exposed workers and 0.5 mu mol mol(-1) creat inine for the controls. This study undoubtedly shows the usefulness of 1-hydroxypyrene as an indicator of internal dose of polynuclear aroma tic hydrocarbons. It can be concluded that the cokery workers at the K ohtia-Jarve plant are exposed to high concentrations of polynuclear ar omatic compounds, and the exposure level is considerably higher during the winter measurements.