URINARY 1-HYDROXYPYRENE AS BIOMARKER OF EXPOSURE TO POLYCYCLIC AROMATIC-HYDROCARBONS IN WORKERS IN PETROCHEMICAL INDUSTRIES - BASE-LINE VALUES AND DERMAL UPTAKE

The suitability of urinary l-hydroxypyrene as a biomarker for the asse ssment of exposure to polycyclic aromatic hydrocarbons (PAH) in petroc hemical industries was evaluated in 562 workers involved in various op erations in petrochemical industries. The median 1-hydroxypyrene conce ntration in 121 of these workers (both smokers and non-smokers) who ha d had no recent occupational exposure to PAH was O.11 mu mol/mol creat inine. The upper limit of the 95% confidence interval was 0.51 mu mol/ mol creatinine. During activities with a low potential exposure to PAH , such as loading bitumen and the handling of clarified slurry oils an d furfural extracts, 1-hydroxypyrene concentrations were only marginal ly increased compared with the values measured in the 121 workers with no recent occupational exposure to PAH. Despite the substantially hig her potential exposure to PAH during clean-out operations of various o il refinery installations, the concentrations of 1-hydroxypyrene in th e workers involved were in the same range. This suggests that personal protection equipment was generally adequate to prevent excessive expo sure. However, in workers digging PAH-contaminated soil and workers en gaged in the production of needle coke from ethylene cracker residue, significantly increased urinary 1-hydroxypyrene concentrations were me asured. A major decrease in urinary 1-hydroxypyrene following the appl ication of dermal protective equipment in the ground workers suggested that skin absorption plays a major role in occupational exposure to P AH. The excretion of 1-hydroxypyrene by the workers of the needle coke plant was investigated in relation to potential determinants of expos ure to PAH. It was indeed found that not only inhalatory but also derm al exposure was a significant determinant of occupational exposure to PAH.