Appendix D - Dossier (PDF) - Tera

date: 20–JUL–2005
5. Toxicity Substance ID: 71–43–2
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of the OEL of 280 mg/m3 or 100 parts per million for THC as
gasoline ranged from 0 to 2.6% for personal long–term
samples. It is recommended that certain operations such as
glycol dehydrators be carefully monitored and that a
task–based monitoring program be included along with the
traditional long– and short–term personal exposure
sampling.
Source: EXXON Biomedical Sciences East Millstone, NJ
Reliability: (1) valid without restriction
07–JUL–2005 (1211)
Remark: An evaluation of modeled benzene exposure and dose
estimates
published in the Chinese–National Cancer Institute
collaborative epidemiology studies.
Risk estimates and cause and effect determinations are
directly dependent on exposure and dose–response
relationships. Recently, relative risks and excess cancer
mortality attributed to occupational benzene exposure have
been published in collaborative studies conducted by
Chinese
investigators and scientists from the National Cancer
Institute. The results of these studies suggest increased
risk of acute nonlymphocytic leukemia at relatively low
benzene concentrations and associations with cancers not
previously associated with benzene exposure. These studies
are potentially important due to their size and potential
to
more thoroughly investigate the link between benzene
exposure and cancer. However, there are questions
concerning
the validity of exposure and dose estimates supporting
relative risk characterizations in these studies. Apparent
discrepancies between modeled exposure and dose estimates
and sources of actual measured exposure information and
clinical markers of benzene toxicity raise serious concerns
questioning the reliability of relative risk and cancer
associations stated in these studies.
Source: EXXON Biomedical Sciences East Millstone, NJ
Reliability: (1) valid without restriction
07–JUL–2005 (166)
Remark: A critique of the exposure assessment in the epidemiologic
study of benzene–exposed workers in China conducted by the
Chinese Academy of Preventive Medicine and the US National
Cancer Institute.
As reviewed in some detail in the present paper, workers
employed in a wide variety of industries were included in
the Chinese benzene study, and were exposed to not only
benzene but also a wide range of other industrial
chemicals.
To attribute any or all health effects observed in the
exposed cohort to benzene without examining other
concomitant exposures is not appropriate. Although it was
stated that one of the major objectives of the expanded
Appendix D: Benzene SIDS Dossier
– 725/957 –