Blood acetone concentration in "normal people" and in exposed workers 16 h after the end of the workshift

Acetone levels were measured by gas chromatography mass spectrometry (GC-MS) in environmental and alveolar air, blood and urine of 89 non-occupationally exposed subjects and in three groups of workers exposed to acetone or isopropanol. Acetone was detected in all samples from non-exposed subjects, with mean values of 840 micrograms/l in blood (Cb), 842 micrograms/l in urine (Cu), 715 mg/l in alveolar air (Ca) and 154 ng/l in environmental air (Ci). The ninety-fifty percentiles were 2069 micrograms/l in Cb, 2206 micrograms/l in Cu and 1675 ng/l in Ca. The blood/air partition coefficient of acetone was 597. Correlations were found in Cb, Cu and Ca. In specimens sampled at the end of the workshift from subjects occupationally exposed to acetone, a correlation was found in the blood, urine, alveolar and environmental air concentrations. The blood/air partition coefficient of acetone was 146. On average, the blood acetone levels of workers were 56 times higher than the environmental exposure level, and the concentration of acetone in alveolar air was 27% more than that found in inspiratory air. The half-life for acetone in blood was 5.8 h in the interval of 16 h between the end of the workshift and the morning after. The morning after a workshift with a mean acetone exposure of 336 micrograms/l, blood and urinary levels were 3.5 mg/l and 13 mg/l, respectively, which were still higher than those found in "normal" subjects. It can be concluded that endogenous production of acetone and environmental exposure to acetone or isopropanol do not affect the reliability of biological monitoring of exposed workers, even 16 h after low exposure.