40
contributions to increasing skin cancer rates around the world (Chang et al. 2014).
On the other hand, incidence will continue to increase as nations with aging populations enter the prime ages for onset of skin cancers (i.e., squamous and basal cell
carcinomas). Malignant melanoma, the most serious of all skin cancers, is also
increasing in incidence and not only arises in older adults but also in adults (Gordon
and Rowell 2015). Beyond the facts mentioned previously, increasing incidence of
UV rays reaching Earth’s surface as a consequence of the ozone hole is also increasing the number of skin cancer patients. The United Nations Environment Programme
(UNEP 1998) has estimated every further 10% depletion of the ozone layer results in
an additional 300,000 non-melanoma and 4500 melanoma skin cancer cases. Today,
skin cancer is the most common type of cancer in fair-skinned populations in many
parts of the world (Narayanan et al. 2010).
The increase of skin cancer incidence represents a big challenge for public
health, and primary prevention is deemed insufficient to reduce that number.
Because of that situation, secondary prevention should be reinforced in order to
improve early detection and treatment and tertiary prevention to reduce the impact
of the ongoing illness. While several good diagnostic tests and skin cancer treatments are available in the sanitary system today, more research is needed in order to
create better and more accuracy tools to fight against this type of cancer. Being UV
radiation the main cause of skin cancer, one of the main challenges for current and
future skin cancer research is to gain a profound understanding regarding the molecular and cellular events activated in the human body as a consequence of the UV
rays. The aim of this chapter is to show how basic research regarding the effects of
UV radiation on the human genetic material can help to improve diagnostic tests
and the treatment of skin cancer, thus improving the patient’s quality of life and
reducing fatalities.
4.2 Literature Review
4.2.1 The Impact of Ultraviolet (UV) Radiation
on Human Life
4.2.1.1 Solar UV Radiation
The sun is the natural and principal source of UV radiation (Fig. 4.1). UV radiation
can be divided, according to its wavelengths, into three categories; UV-A (320–
400 nm), UV-B (280–320 nm), and UV-C (100–280 nm). About 95% of the total
UV radiation reaching Earth’s surface is categorized as UV-A, while UV-B radiation accounts for the final 5% (Britt 2002). UV-A rays are absorbed by the skin and
are as such responsible for its aging and wrinkling, while UV-B radiation produces
erythema, burns, and skin cancer (Ohnaka 1993). On the other hand, UV-C rays are
absorbed by the ozone layer and therefore do not reach Earth’s surface.
M. B. Federico
contributions to increasing skin cancer rates around the world (Chang et al. 2014).
On the other hand, incidence will continue to increase as nations with aging populations enter the prime ages for onset of skin cancers (i.e., squamous and basal cell
carcinomas). Malignant melanoma, the most serious of all skin cancers, is also
increasing in incidence and not only arises in older adults but also in adults (Gordon
and Rowell 2015). Beyond the facts mentioned previously, increasing incidence of
UV rays reaching Earth’s surface as a consequence of the ozone hole is also increasing the number of skin cancer patients. The United Nations Environment Programme
(UNEP 1998) has estimated every further 10% depletion of the ozone layer results in
an additional 300,000 non-melanoma and 4500 melanoma skin cancer cases. Today,
skin cancer is the most common type of cancer in fair-skinned populations in many
parts of the world (Narayanan et al. 2010).
The increase of skin cancer incidence represents a big challenge for public
health, and primary prevention is deemed insufficient to reduce that number.
Because of that situation, secondary prevention should be reinforced in order to
improve early detection and treatment and tertiary prevention to reduce the impact
of the ongoing illness. While several good diagnostic tests and skin cancer treatments are available in the sanitary system today, more research is needed in order to
create better and more accuracy tools to fight against this type of cancer. Being UV
radiation the main cause of skin cancer, one of the main challenges for current and
future skin cancer research is to gain a profound understanding regarding the molecular and cellular events activated in the human body as a consequence of the UV
rays. The aim of this chapter is to show how basic research regarding the effects of
UV radiation on the human genetic material can help to improve diagnostic tests
and the treatment of skin cancer, thus improving the patient’s quality of life and
reducing fatalities.
4.2 Literature Review
4.2.1 The Impact of Ultraviolet (UV) Radiation
on Human Life
4.2.1.1 Solar UV Radiation
The sun is the natural and principal source of UV radiation (Fig. 4.1). UV radiation
can be divided, according to its wavelengths, into three categories; UV-A (320–
400 nm), UV-B (280–320 nm), and UV-C (100–280 nm). About 95% of the total
UV radiation reaching Earth’s surface is categorized as UV-A, while UV-B radiation accounts for the final 5% (Britt 2002). UV-A rays are absorbed by the skin and
are as such responsible for its aging and wrinkling, while UV-B radiation produces
erythema, burns, and skin cancer (Ohnaka 1993). On the other hand, UV-C rays are
absorbed by the ozone layer and therefore do not reach Earth’s surface.
M. B. Federico