Determination of S-phenylmercapturic acid in the urine--an improvement in the biological monitoring of benzene exposure.
In an inhalation study rats were exposed to different doses of benzene, ranging from 1 to 500 p.p.m. The urine was sampled during the inhalation period of 8 h and for 24 h after exposure. S-Phenylmercapturic acid (S-PMA) in the urine was determined by amino acid analysis. Phenol was measured by gas chromatography/mass spectrometry. In both cases the correlation between benzene uptake and the excretion of the urinary metabolites was significant at the level of P = 0.01. The same significant correlation (P = 0.01) was demonstrable after i.p. administration of benzene at doses between 0.7 and 140.0 microliters/kg body weight. In the case of two collectives of workers who were exposed to air concentrations of up to 0.15 p.p.m. for 8 h and of up to 1.13 p.p.m. for 12 h respectively, the amount of S-PMA in the first urine samples after the shift was significantly higher than in samples collected at the beginning of the shift (P = 0.01). In the first collective the mean values and the standard deviations of the S-PMA concentrations in the samples at the beginning of the shift were 12.0 +/- 16.7 compared with 48.5 +/- 64.5 micrograms/g creatinine at shift end. In the second collective they were 25.1 +/- 25.1 compared with 70.9 +/- 109.2 micrograms/g creatinine. The level of significance of the difference between the concentration values of S-PMA at the beginning and end of the shift was P = 0.01. The phenol concentration did not differ significantly. These results suggest that S-PMA can be regarded as a useful indicator for monitoring individuals and collectives exposed to benzene at levels even less than 1 p.p.m.
Stommel
P
P
Institute of Hygiene and Occupational Medicine, Essen University, FRG.
Müller
G
G
Stücker
W
W
Verkoyen
C
C
Schöbel
S
S
Norpoth
K
K
D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000652:urine; D000818:Animals; D001554:Benzene / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure; D006801:Humans; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
C053003:S-phenyl-N-acetylcysteine; D001554:Benzene; D000111:Acetylcysteine