world cancer report - iarc
world cancer report - iarc
world cancer report - iarc
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REDUCTION OF EXPOSURE TO ULTRAVIOLET RADIATION<br />
SUMMARY<br />
> Encouragement of sun-protective behaviour<br />
is the most effective public health<br />
measure to reduce incidence of skin<br />
<strong>cancer</strong>, particularly in highly susceptible<br />
white populations, and especially in children.<br />
> Available options include sun avoidance<br />
by using shade, wearing protective<br />
clothing and using sunscreens.<br />
> Often, the protective effect of sunscreens<br />
is counteracted intentionallyextended<br />
periods of sun exposure,<br />
notably during vacations.<br />
> Downward trends in melanoma incidence<br />
in some countries reflect a successful<br />
implementation of prevention<br />
policies.<br />
Skin <strong>cancer</strong> is the most common <strong>cancer</strong><br />
<strong>world</strong>wide, although only one form,<br />
melanoma, is comprehensively documented<br />
(Melanoma, p253). Over 100,000 cases<br />
of melanoma occurred <strong>world</strong>wide in 1990.<br />
It is estimated that 2.75 million basal and<br />
squamous cell carcinomas were diagnosed<br />
in 1985, which may be equated with<br />
30% of all newly diagnosed <strong>cancer</strong> [1].<br />
Such non-melanocytic <strong>cancer</strong>s are usually<br />
not life-threatening, but are cause for the<br />
provision of medical services, including<br />
hospital admissions.<br />
Solar radiation is established as a cause of<br />
skin <strong>cancer</strong> and may account for 80-90% of<br />
such disease [2]. The incidence of skin<br />
<strong>cancer</strong> in different communities varies<br />
according to skin type and distance from<br />
the equator. The highest rates occur in<br />
Australia, where <strong>cancer</strong> incidence is dominated<br />
by skin <strong>cancer</strong> that, in terms of incident<br />
cases, outnumbers all other forms of<br />
<strong>cancer</strong> by more than three to one [3].<br />
The scope of sun-protection strategy<br />
The extent of individual exposure to sunlight<br />
is, in the first instance, determined<br />
by personal behaviour. Two types of exposure<br />
can be distinguished: intentional<br />
exposure (usually in the context of achieving<br />
a tan) and unintentional exposure in<br />
the course of daily life. The immediate<br />
goal of sun protection programmes is to<br />
affect individual behaviour, specifically in<br />
relation to intentional exposure. Programmes<br />
may be targeted to particular<br />
population groups or to the community as<br />
a whole. Epidemiological evidence indicates<br />
that sun exposure during childhood<br />
and adolescence contributes markedly to<br />
lifelong risk of skin <strong>cancer</strong> [4]. The intensity<br />
and duration of targeted intervention<br />
largely determines the impact of such<br />
programmes. Individual sun-related<br />
behaviour may be influenced by mass<br />
media campaigns and the provision of<br />
educative material. Thus the “Sun<br />
Awareness” programme in Canada used<br />
strategies for improving community<br />
knowledge about skin <strong>cancer</strong> and sun<br />
protection, which included mass media,<br />
distribution of educational brochures and<br />
development of a school curriculum to<br />
promote sun protection [5].<br />
Prevention programmes may appropriately<br />
focus on young people, parents, caregivers<br />
and the settings in which young<br />
people spend time outdoors. In relation to<br />
children and adolescents, relevant agencies<br />
to be engaged in sun protection programmes<br />
include early childhood services,<br />
schools and those involved in providing<br />
sport and recreational activity.<br />
Attention should also be paid to adults<br />
with high intermittent or cumulative sun<br />
exposure, specifically including workplace<br />
exposure for those involved in agricultural,<br />
forestry, fishery, construction<br />
and outdoor electricity transmission and<br />
similar work [6]. General practitioners<br />
and community health nurses may be<br />
encouraged to play a role in educating<br />
specific sections of the community to<br />
adopt improved sun protective behaviour.<br />
Provision of structural and environmental<br />
support to reduce sun exposure necessitates<br />
an infrastructure that is responsive<br />
and well resourced to steer relevant programmes<br />
and strategies [7].<br />
Means of intervention<br />
Public health programmes developed to<br />
reduce skin <strong>cancer</strong> focus on a range of<br />
means to reduce sun exposure. The<br />
means to be used may vary between<br />
areas of high and low sunlight. Relevant<br />
strategies may include dissemination of<br />
knowledge about the intensity of sunlight<br />
in the local environment, scheduling<br />
activity or work to be indoors around<br />
solar noon, minimizing the time spent<br />
outdoors in sunny seasons, and advice<br />
as to how to avoid direct sunlight exposure<br />
during times when the ambient<br />
intensity is high. Protection when in<br />
direct sunlight may be achieved by wearing<br />
protective clothing, hats or sunglasses<br />
and using sunscreens [8].<br />
Fig. 4.11 Sun-protective behaviour can be taught<br />
at a young age.<br />
Fig. 4.12 T-shirt and sign advertising the<br />
“SunSmart Campaign” on a beach in Australia.<br />
Reduction of exposure to ultraviolet radiation 141