world cancer report - iarc

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