manufacture, processing and use of stainless steel - International ...

hot rolling mills, stainless steel foundry 12 , and maintenance). Expected numbers of deaths
were based on national mortality rates, adjusted for sex, age and calendar period. Overall
mortality was close to expectation (Observed 452, Expected 434.7, SMR 104, 95% CI 95 to
114). There were no significant mortality excesses for any cancer site. For lung cancer
mortality, there was a non-significant increase (Observed 39, Expected 29.6, SMR 132, 95%
CI 94 to 180). When lung cancer mortality data were analysed according to the workshop
where subjects were employed, the only significant increase was in workers employed in the
stainless steel foundry (Observed 11, Expected 4.8, SMR 229, 95% CI 114 to 409). In this
group of workers, the greatest excess lung cancer mortality occurred in workers with at least
30 years since first employment (SMR 324, 95% CI 119 to 705). Lung cancer mortality
among ferroalloy production workers was less than expected (Observed 2, Expected 3.0, SMR
68, 95% CI 80 to 245), among workers from the stainless steel melting and casting workshops
was close to expectation (Observed 7, Expected 6.7, SMR 104, 95% CI 42 to 215), and in the
hot rolling mills workshops showed a non-significant increase (Observed 17, Expected 11.3,
SMR 151, 95% CI 88 to 242). For all workshops combined, lung cancer mortality did not
show any relationship with either time since first exposure or duration of employment. No
exposure data were provided in this study. It was reported, however, that in some of the
workshops, including the stainless steel foundry, exposure to PAHs may occur, originating
from moulds and cores, in addition to exposure to metal fumes.
Overall, in this study, no elevated lung cancer risk was apparent for workers involved in the
stainless steel production (melting shop) process. The study provides some evidence of
increased lung cancer risk in workers in a stainless steel foundry which was integrated into a
stainless steel production plant, but provides little indication as to causative agent(s). It should
be noted that “iron and steel founding” is considered by IARC to be a Group 1 carcinogenic
activity (IARC, 1984 & 1987). There is no definitive identification of the carcinogenic agents
by IARC. PAHs, silica, phenol, isocyanates, various amines and formaldehyde (apparently
arising from the materials added to the foundry sand, including organic binders) and "metal
fumes" are suggested as possibilities. The carcinogenic agents are not apparently specific to
the metals being cast. It should also be noted that, in Europe, only a very small number of
people is now employed as stainless steel foundry workers.
Summary of epidemiological investigations
Epidemiological studies of cancer mortality among stainless steel production workers are
summarised in Table 2.2. These studies do not provide convincing evidence of elevated lung
cancer risk in workers involved in stainless steel manufacture. In one of the studies,
information was provided on excess lung cancer risk in stainless steel foundry workers.
12 In this study, foundry operations were integrated into the stainless steel production process and the
foundry was located in the same plant. Foundry operations are not strictly part of the production
process and, in the modern industry, it would be more appropriate to consider them under "stainless
steel processing".
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