S. Ghittori et al., EVALUATION OF OCCUPATIONAL EXPOSURE TO BENZENE BY URINALYSIS, International archives of occupational and environmental health, 67(3), 1995, pp. 195-200
Urinary phenol determinations have traditionally been used to monitor
high levels of occupational benzene exposure. However, urinary phenol
cannot be used to monitor low-level exposures. New biological indexes
for exposure to low levels of benzene are thus needed. The aim of this
study was to investigate the relations between exposure to benzene (A
-benzene, ppm), as measured by personal air sampling, and the excretio
n of benzene (U-benzene, ng/l), trans,trans-muconic acid (MA, mg/g cre
atinine), and S-phenylmercapturic acid (PMA, mu g/g creatinine) in uri
ne. The subjects of the study were 145 workers exposed to benzene in a
chemical plant. The geometric mean exposure level was 0.1 ppm (geomet
ric standard deviation = 4.16). After logarithmic transformation of th
e data the following linear regressions were found: log (U-benzene, ng
/l) = 0.681 log (A-benzene ppm) + 4.018; log (MA, mg/g creatinine) = 0
.429 log (A-benzen ppm) - 0.304; and log (PMA, mu g/g creatinine) = 0.
712 log (A-benzene ppm) + 1.664. The correlation coefficients were, re
spectively, 0.66, 0.58, and 0.74. On the basis of the equations it was
possible to establish tentative biological limit values corresponding
to the respective occupational exposure limit values. In conclusion,
the concentrations of benzene, mercapturic acid, and muconic acid in u
rine proved to be good parameters for monitoring low benzene exposure
at the workplace.