Appendix D - Dossier (PDF) - Tera

date: 20–JUL–2005
5. Toxicity Substance ID: 71–43–2
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worked for at least 6 months between January 1, 1972 and
December 31, 1981, was conducted. The control cohort of
28,257 individuals who had worked in the same cities for at
least 6 months, was chosen from 83 machine production,
textile and cloth factories in which there was no known
exposure to benzene or other occupational carcinogens.
Thirty cases of leukaemia (of whom 25 had died) were
identified in the benzene cohort and four (all of whom had
died) in the control group, giving mortality rates from
leukaemia of 14/100,000 person–years and 2.01/100,000
person–years respectively. The numbers of leukaemia deaths
were significantly in excess for both male and female
workers [SMR=501 (95% CI=292–802) and 830 (95% CI=358–1635)
respectively]. The mean age of the leukaemia patients was
lower in the exposed group and the average latency period
was 11.4 years (ranging form 0.8–49.5 years). The benzene
concentrations, as determined in a grab sampling programme,
ranged from 7–1100 mg/m3 (3–340 ppm) but were mainly in the
range of 50–500 mg/m3 (16–160 ppm). Chronic benzene
poisoning and aplastic anaemia were identified in 196
exposed workers, seven of whom died from leukaemia. The
leukaemia mortality rate among these poisoning cases was
700.7/100,000 person–years; 49 times greater than that in
the benzene workers (Yin et al. 1987). It has been
commented that little detail has been given of the methods
used to take account of the possible confounding effects of
smoking (WHO, 1993).
Source: Deutsche Shell Chemie GmbH Eschborn
06–JAN–1997 (1252) (1298)
Remark: COKE OVEN WORKERS
A number of cohort studies have looked at mortality in coke
oven workers. No excesses of leukaemias and lymphomas
combined or of leukaemias respectively were found in North
American or Dutch coke oven workers (Redmond et al. 1972;
Swaen et al. 1991). Exposures to benzene were not reported
in these studies.
Preliminary results from a total 6520 British male coke
plant workers have been reported (Hurley et al. 1991).
Personal air sampling from two cohorts of benzole workers
(84 and 307 workers respectively) showed benzene
concentrations of