THE SUITABILITY OF THE URINARY METABOLITE 1-HYDROXYPYRENE AS AN INDEX OF POLYNUCLEAR AROMATIC HYDROCARBON BIOAVAILABILITY FROM WORKERS EXPOSED TO CARBON-BLACK

Levels of airborne dust have been measured in the breathing zone of five warehouse packers in a carbon black manufacturing plant on consecutive days over 1 week. Post-shift urine samples were collected on individuals over the week and the concentration of the pyrene metabolite 1-hydroxypyrene have been measured. A questionnaire was used to assess the likelihood of potential confounding factors, such as direct exposure to feedstock oil, as well as smoking and diet. The arithmetic mean both of airborne dust and of excreted 1-hydroxypyrene for each individual have been correlated (a) with the constraint that the regression line pass through the origin, and (b) without this constraint. The slope of the regression through the origin was significant and that of the second regression (not through the origin) was not. The statistical test to determine whether excretion on days after Monday was higher than that on Monday itself proved highly significant. The results suggest that 1-hydroxypyrene may be a useful indicator of exposure to the PNAs adsorbed onto carbon black.