Appendix D - Dossier (PDF) - Tera

date: 20–JUL–2005
5. Toxicity Substance ID: 71–43–2
______________________________________________________________________________
and external benzene exposures in this study. They also
note
that creatinine elimination increases with body mass, and
that excretion of MA and HQ standardised per g creatinine
approximates excretion standardised per kg body weight
thereby providing a surrogate estimate of internal
exposure.
Based on this analysis, they suggest that children have a
higher internal exposure than adults. The basis of this
conclusion is not clear, however, given the probable
contribution of dietary precursors to urinary MA and HQ.
Source: A.K. Mallett Surrey
Conclusion: Muconic acid and hydroquinone do not appear to be reliable,
specific markers of low benzene exposure due to potential
confounding by food–borne precursors of these substances.
This may explain the absence of correlation between urinary
metabolite levels and benzene exposure in this study.
16–MAR–2004 (638)
Type of experience: other: benzene oxide–albumin adducts in human blood
Method: An expanded version of this study and its methods was
reported subsequently by Qu et al. (2003) Validation and
evaluation of biomarkers in workers exposed to benzene in
China. Research Report 115, Health Effects Institute,
Boston
MA.
Appendix D: Benzene SIDS Dossier
SUBJECTS AND METHODS
Thirty benzene–exposed workers were recruited from three
factories in Shanghai, China where benzene was used as a
rubber solvent, in the manufacture of adhesive tape or in
paint. Forty three control workers (frequency matched with
exposed group by gender and age) were recruited from a
sewing machine factory and an administrative facility in
the
same geographic region.
EXPOSURE MESAUREMENTS
Exposure to benzene was assessed measured by personal
monitoring (passive; full work shift on 5 or 6 consecutive
days).
ADDUCT MEASUREMENTS
Benzene oxide–albumin adducts (BO–Alb) in blood were
determined by GC–MS in negative chemical ionisation mode.
(Blood collection details not given).
STATISTICAL METHODS
Results of analyses for BO–Alb in blood and personal
exposure data for the exposed worker population were
natural
log transformed and subject to regression analysis. This
analysis was performed twice, once on the raw BO–Alb
results
and again after subtraction of the geometric mean value for
the controls from data for the exposed population. Within
– 765/957 –