Analysis of urinary S-phenylmercapturic acid and trans, trans-muconic acid as exposure biomarkers of benzene in petrochemical and industrial areas of Korea.
OBJECTIVE
Recently, S-phenylmercapturic acid (S-PMA) and trans,trans-muconic acid (t,t-MA) in urine have been proposed as reliable biomarkers for monitoring occupational exposure to benzene. The aim of this study was to test the applicability of S-PMA and t,t-MA as exposure biomarkers and to monitor the occupational exposure level and the extent of environmental contamination from benzene in Korea.


METHODS
The urinary excretion of S-PMA and t,t-MA in rats after the intraperitoneal administration of benzene (0.88-800 mg/kg body weight, 7 days) was examined. These biomarkers were also validated in human urine samples collected from elementary schoolchildren in several industrial areas including chemical manufacturing plants, oil refineries, and natural gas-producing installations in Korea. Urine was collected from elementary schoolchildren in a mountain village with no known occupational exposure to benzene and air pollution as the reference group.


RESULTS
In rats, there was a significant relationship between the benzene concentration and the excretion of the urinary S-PMA and t,t-MA as a function of concentration, and the excretion of benzene metabolites peaked on the first day after intraperitoneal administration. In human urine, higher levels of S-PMA and t,t-MA were detected more frequently in petrochemical industrial areas than in areas with no known occupational exposure to benzene.


CONCLUSIONS
These results show that the quantitative determination of S-PMA and t,t-MA in urine can be used as a reliable exposure biomarker for benzene, and they also suggest that extensive attention to benzene exposure is needed for maintaining the health of the population in Korea.
Fang
M Z
MZ
Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Korea.
Shin
M K
MK
Park
K W
KW
Kim
Y S
YS
Lee
J W
JW
Cho
M H
MH
D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000652:urine; D000818:Animals; D015415:Biomarkers / Q000652:urine; D002617:Chemical Industry; D002648:Child; D004781:Environmental Exposure; D006801:Humans; D007723:Korea; D008297:Male; D016273:Occupational Exposure; D051381:Rats; D017207:Rats, Sprague-Dawley; D012424:Rural Population; D013011:Sorbic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D014505:Urban Population
D015415:Biomarkers; C005939:muconic acid; C053003:S-phenyl-N-acetylcysteine; D000111:Acetylcysteine; D013011:Sorbic Acid