world cancer report - iarc

REDUCTION OF OCCUPATIONAL AND ENVIRONMENTAL EXPOSURES
SUMMARY
> The prevention of cancer attributable to
occupational and environmental exposures
is primarily achieved by regulatory
action.
> Relevant measures include replacement
of carcinogens with alternative chemicals
or processes, improved ventilation,
re-engineered manufacturing processes
and, if this fails, use of protective clothing
and equipment.
> A significant reduction in occupational
cancer attributable to implementation of
preventive measures has been demonstrated
in many instances. However,
there remains a burden of past exposure,
particularly to asbestos.
In developed countries, it has been estimated
that about 5% of all cancers are
attributable to occupational exposures
and about 1% to pollution [1] (Occupational
exposure, p33; Environmental pollution,
p39). These minor proportions might
not command immediate attention.
However, the cancers in question are
immediately preventable, particularly
those resulting from occupational exposures.
In principle, an individual should
not have to accept an increased risk of
cancer which has been recognized as
being caused by doing a particular job. It
is notable that exposure to occupational
carcinogens and to environmental pollutants
is largely involuntary, as distinct
from “lifestyle” exposures, such as active
smoking, alcohol drinking and sun exposure,
the extent of which are largely a matter
of personal choice.
Prevention of cancers attributable to
occupational exposures and environmental
pollution involves at least two stages:
firstly, identification of the specific agent
or situation responsible for an increased
cancer incidence and secondly, the imposition
of appropriate regulatory controls.
However, regulatory control of exposure
to carcinogens or hazardous environments
must vary according to the situation
being addressed. Even in relation to
the same agent, there may be several
options and hence the procedures adopted
by different countries may vary.
Occupational cancer
Prevention of exposure
The primary strategy for prevention of
occupationally induced cancer involves
preventing exposure to the recognized
carcinogen in question. One option is to
cease production, exemplified by the
phasing out of 4-aminobiphenyl in the
United Kingdom, following reports of
increased risk of bladder cancer among
exposed American workers [2]. Another
approach is the adoption of protective
measures, including those involving building
design and ventilation systems.
Consideration may be given to altered
means of production (e.g. the use of
“closed” rather than “open” engineering).
As a general rule, reduced emissions
and/or improved ventilation are more efficient
than the use of protective equipment
in achieving a durable reduction in exposure.
Reduction of emission can often be
achieved for chemicals generated incidentally
in the course of production, such as
intermediates formed during chemical
manufacturing processes. However,
reduction of exposure at source may be
difficult to achieve when the hazardous
material is the final manufactured product.
Adoption of protective clothing and “safe”
handling procedures may be perceived as
the last resort in a general assessment of
preventive measures, but is recognized as
being necessary and appropriate to particular
situations. Safety equipment must
be properly related to the hazard and be
comfortable. Such equipment may include
gloves, gowns, masks and/or respirators
depending on the situation. Related meas-
ures include use of proper warning labels
and secure storage arrangements.
Activities of the International Labour
Organization (ILO) aimed specifically at
the prevention of occupational cancer
include the adoption and promotion of the
Occupational Cancer Convention and
Recommendation (ILO, 1974) and the production
of a publication concerning prevention
and control of occupational cancer
(ILO, 1988). The Occupational Cancer
Convention specifies the principles to be
adopted and had, in 2001, been signed by
35 Member States. Article 3 states that
“Each Member which ratifies this
Convention shall prescribe the measures
to be taken to protect workers against the
risks of exposure to carcinogenic substances
or agents and shall ensure the
establishment of an appropriate system of
records.”
Screening
Screening of occupationally exposed
workers for physical or biological indicators
of exposure has been proposed, but
Fig. 4.8 Clothing to prevent contamination with
chemical waste.
Reduction of occupational and environmental exposures 135