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