world cancer report - iarc

there is no evidence for the efficacy of this
approach. This is specifically the case for
lung cancer and mesothelioma among
asbestos-exposed workers (screened
using chest X-rays or cytological examination
of sputum) and bladder cancer among
workers exposed to aromatic amines
(screened using cytological or mutagenicity
analysis of urothelial cells in the urine).
Education programmes directed at reducing
any delay in examination and diagnosis
of workers developing symptoms of disease
are an option. These programmes
not only require awareness and information
campaigns, but also require appropriate
facilities for diagnosis and treatment
136 Prevention and screening
[3]. In Finland, there is a policy of increasing
awareness about carcinogens in the
workplace and employers are required to
maintain files on all employees, recording
all exposures.
Actions and outcomes
Prompt regulatory action may be seen to
have followed the identification of vinyl
chloride as an occupational carcinogen. An
occupational exposure limit of 500 parts
per million (ppm) for vinyl chloride
monomer was common during the 1960s,
and was based on the explosive properties
of the chemical. However, in 1974, several
cases of an otherwise very rare cancer,
angiosarcoma of the liver, were described
among workers exposed to vinyl chloride,
and this was followed soon after by the
results of animal experiments, confirming
the carcinogenicity of this compound.
These findings led to a rapid reduction in
recommended exposure levels for vinyl
chloride monomer to 10 ppm or less.
However, a similar quick response to
accumulating evidence of an unacceptable
hazard has not occurred for other
occupational carcinogens. The history of
occupational exposure to asbestos is illustrative
of an unacceptable time-lag
between identification of risk and regulatory
action. Epidemiological results indi-
Country Year Butadiene concentration (mg/m 3) Interpretation
Australia 1991 22 (Probable human carcinogen) Time-weighted average
Belgium 1991 22 (Probable human carcinogen) Time-weighted average
Czechoslovakia 1991 20 Time-weighted average
40 Ceiling
Denmark 1993 22 (Potential occupational carcinogen) Time-weighted average
Finland 1998 2.2 Time-weighted average
France 1993 36 Time-weighted average
Germany 1998 34 (Human carcinogen) Technical exposure limit
11
Hungary 1993 10 (Potential occupational carcinogen) Short-term exposure limit
The Netherlands 1996 46 Time-weighted average
The Philippines 1993 2200 Time-weighted average
Poland 1991 100 Time-weighted average
Russia 1991 100 Short-term exposure limit
Sweden 1991 20 (Suspected of having a carcinogenic potential) Time-weighted average
40 (Suspected of having a carcinogenic potential) Ceiling
Switzerland 1991 11 (Suspected of being a carcinogen) Time-weighted average
Turkey 1993 2200 Time-weighted average
United Kingdom 1991 22 Time-weighted average
United States:
ACGIH (Threshold Limit Value) a 1997 4.4 (Suspected human carcinogen) Time-weighted average
NIOSH (Recommended Exposure Limit) 1997 (Potential occupational carcinogen: lowest feasible Time-weighted average
concentration)
OSHA (Permissible Exposure Limit) 1996 2.2 Time-weighted average
Limits and guidelines from International Labour Office (1991); United States Occupational Safety and Health Administration (OSHA, 1996); American Conference of
Governmental Industrial Hygienists (ACGIH, 1997); United States National Library of Medicine (1997); Deutsche Forschungsgemeinschaft (1998); Ministry of Social
Affairs and Health (1998). a Countries that follow the ACGIH recommendations for threshold limit values include Bulgaria, Colombia, Jordan, Republic of Korea, New
Zealand, Singapore and Viet Nam.
Table 4.4 International occupational exposure limits and guidelines for butadiene (which is classed by IARC as a probable human carcinogen, Group 2A).