Appendix D - Dossier (PDF) - Tera

date: 20–JUL–2005
5. Toxicity Substance ID: 71–43–2
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average (LTA) exposure concentrations, rather than the
estimated cumulative exposure of benzene. A dose rate
effect is defined as an effect which primarily relies on
exposure concentration, above that which would be predicted
by the simple mathematical product of concentration X time.
The three sets of LTA exposure estimates developed by
previous authors (Rinsky et al., 1981; Crump & Allen, 1984;
Paustenbach et al., 1992) were used in the study. Subsets
of Pliofilm employees always exposed to less than or equal
to specific concentration of benzene were examined. The
results suggest that (a) AMML risk is shown only above a
critical concentration of benzene exposure, measured as a
long term average and experienced for years, (b) the
critical concentration is between 160 and 192 mg/m3 (50 and
60 ppm) using exposure estimates from three previous
exposure assessments, (c) using the lowest exposure
estimates (Rinsky et al., 1981), there was no suggestion of
excess risk for workers who experienced LTA concentrations
over their career of 64 mg/m3 (20 ppm) or below, and (d)
risks for total leukaemia are driven by risks for AMML,
suggesting that AMML is the cell type related to benzene
exposure.
Source: Deutsche Shell Chemie GmbH Eschborn
06–JAN–1997 (1023)
Remark: This study of 33,815 men, who first started work in the
rubber industry between 1 January 1946 and 31 December
1960,followed their mortality experience up to 31 December
1975 to ascertain the number of deaths attributable to
malignant disease and to compare these with the expected
number calculated from the published mortality rates
applicable to the male population of England and Wales and
Scotland. No quantitative estimates of benzene exposures
were available. A statistically significant excess of both
lung and stomach cancer mortality was observed. A small
excess of oesophageal cancer was also observed in both the
tire and general rubber goods manufacturing sectors.
Source: Deutsche Shell Chemie GmbH Eschborn
06–JAN–1997 (870)
Remark: This is a prospective cohort study of approximately 11,000
male and 600 female employees in the Australian petroleum
industry who had worked at least 5 years in 1981–1983.
Jobswere coded according to classifications developed by
the
American Petroleum Institute to assess potential exposure.
However, there were no quantitative exposure data available
on benzene or other exposures; potential exposures were
ranked on a qualitative scale from one to four. Deaths
fromlympho–hematopoietic cancers (LHC) were greater than
expected based on the australian national population.
(Standardized Mortality Ratio [SMR] = 138; 95% Confidence
Interval [CI] = 63–263). Incident cancers in this category
were significantly elevated (Standardized Incidence Ratio
[SIR] = 204; 95% CI = 125–315). All leukemia cell types
Appendix D: Benzene SIDS Dossier
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