Possible sources of urinary benzene among nonoccupationally exposed Japanese subjects.
Unmetabolized benzene in urine (U-benzene) is known to be the best marker among the indices for the biological monitoring of occupational and environmental exposure to benzene. In this study, we determined the levels of U-benzene among Japanese university students exposed to benzene nonoccupationally and analyzed the relation between U-benzene levels and the possible factors responsible for environmental benzene exposure. In urinalysis, U-benzene concentration among 124 students was detected in the range from 18 (minimum detection limit) to 249 ng/l. The frequency distribution of U-benzene concentration peaked at 0-19 ng/l. Mean and median values of 40 and 20 ng/l for U-benzene concentration in nonoccupationally exposed subjects were lower than those in a previous study. Stepwise multiple linear regression analysis was performed to assess the potential sources of exposure to environmental benzene by analyzing the relation between U-benzene and personal, behavioral, and environmental factors. The results showed that only smoking habit (P < 0.01) and residential house age (P < 0.05) were independent determinants of U-benzene levels. In addition, U-benzene levels in relation to smoking and house age suggested that these factors could be associated with the synergistic elevation of U-benzene. The present study showed U-benzene levels among non-occupationally exposed Japanese subjects and revealed that the major exposure sources to benzene in the general environment were tobacco smoking and indoor air contamination.
Department of Hygiene and Public Health, Kagawa University, Japan. suna@med.kagawa-u.ac.jp
Shigeru
S
Suna
Tomohiro
T
Hirao
Fumiyuki
F
Asakawa
Takeshi
T
Suzue
Toshifumi
T
Mannami
Famihiko
F
Jitsunari
D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000652:urine*; D001554:Benzene / Q000032:analysis* / Q000378:metabolism; D015415:Biomarkers / Q000652:urine; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D007564:Japan; D016014:Linear Models; D008297:Male; D018709:Statistics, Nonparametric; D055815:Young Adult
D000393:Air Pollutants; D015415:Biomarkers; D001554:Benzene