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.
Suna
Shigeru
S
Department of Hygiene and Public Health, Kagawa University, Japan. suna@med.kagawa-u.ac.jp
Hirao
Tomohiro
T
Asakawa
Fumiyuki
F
Suzue
Takeshi
T
Mannami
Toshifumi
T
Jitsunari
Famihiko
F
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