Ultraviolet radiation causes skin cancer
Excessive exposure to ultraviolet (UV) radiation can cause health problems. Skin can burn, age prematurely and the risk of skin cancer is increased. UV radiation can also damage the eyes. UV radiation also has positive effects, as UV radiation causes the skin to produce vitamin D.
The most common skin cancers with a clear association with UV radiation are basal cell carcinoma, squamous cell carcinoma, and melanoma.
Basal and squamous cell carcinomas are usually benign and develop as a result of long-term exposure, most often to the elderly. They occur mainly in the face and hands, which are constantly exposed to the sun's radiation.
Malignant melanoma typically develops on the skin of the body or limbs. Unlike other skin cancers, melanoma occurs also in young people. Repeated skin burning in childhood or adolescence increases the risk of developing melanoma. Therefore, protecting children from the sun is important.
Melanoma has increased dramatically in all countries inhabited by Caucasians. Although growth has stabilized in recent years, melanoma is still over ten times more common in Finland than in the early 1950s. There are no other known reasons for this increase other than changes in population clothing and sunbathing habits. People also travel on sun holidays to countries where they are exposed to higher levels of UV radiation.
In Finland more than 1700 people are diagnosed with melanoma and about 200 die from melanoma each year. Basal and squamous cell carcinomas are more common, but only approximately forty people die of these cancers each year.
Although melanoma has a poor reputation, it is not one of the worst types of cancer. Early tumour removal will completely cure the disease. About 94 percent of those with melanoma will survive for five years or more.
It is advisable to monitor your skin, especially if you have a sensitive skin type or other features that indicate an increased risk of melanoma. Individual factors such as the sensitive skin type, the abundance of moles and freckles of the skin clearly increase the risk of getting melanoma.
Risk factors for melanoma include:
- skin burns under the age of 15
- sensitive skin (skin types I and II)
- plenty (over 150) of pigment moles
- unusual moles
- abundant sunbathing and sun bed/solarium use
- a close relative has a history of melanoma.
Monitor your skin and see your doctor if:
- a mole begins to grow
- a mole becomes ulcerated, itchy or otherwise irritated
- the border of the mole is blurred and asymmetrical
- colour of a mole ranges from bluish black to reddish
- tiny satellite moles begin to grow around the mole
- other abnormal changes appear on the skin (30% of melanoma originates from other parts of the skin than moles).
Your skin may burn in the sun
If you stay in the sun too long, your skin will burn. The symptoms of burns do not appear on the skin until hours after the actual burn. A slight burn will appear as a reddening of the skin. If the skin burns badly, swelling and blistering of the skin will occur. The thin skin of children is particularly sensitive to the sun. Burning clearly increases the risk of skin cancer, especially repeated skin burns in childhood or adolescence increase the risk of melanoma. Therefore, protecting children from the sun is important.
UV radiation causes snow blindness and cataracts
Intense UVB radiation from the sun can cause inflammation of the cornea of the eye, also called snow blindness. UVB damages the corneal and conjunctival epithelial cells of the eye. Symptoms include redness of the conjunctiva, photosensitivity, increased tearing, and pain. Symptoms appear after a couple of hours of UV exposure. Due to the rapid renewal of the cells in the eye’s epithelial layers, the symptoms disappear within a few days.
Abundant and prolonged exposure to sunlight can also cause slowly developing clouding in the lens of the eye. The damage eventually results in cataracts.
The tolerance of skin types varies
Skin types have different tolerances: people can be roughly divided into six skin types, depending on how well the skin can tolerate the sun. Those with skin that burns easily and tans poorly (skin types I and II) have a higher risk of developing melanoma.
Children's skin is thinner and unable to produce pigment in the same way as adult skin, and is therefore classified as the most sensitive skin type I.
The easiest way to determine your own skin type is to answer two questions:
- Does your skin burn every summer when for the first time in the sun?
- Do you tan after sunbathing?
Few people belong to only one specific skin type. The skin type scale is only indicative.
Type I people are often very light-skinned, red-haired and freckled, burn very quickly in the sun, and do not tan at all.
Type II people are light-skinned, blonde-haired, blue or green-eyed people who burn frequently and tan slightly.
Type III members typically have brown hair and gray or brown eyes. They withstand the sun relatively well, sometimes burn, and tan well.
Type IV subjects have light brown/olive skin, brown eyes, and dark brown or black hair. They rarely burn and tan well.
Europeans most often fall into these four skin types. One third of Finns belong to Type I or II and about half to Type III. Only one in ten is Type IV, which is prevalent in Southern Europe.
Skin types V and VI are naturally dark-skinned and -haired and do tolerated the sun well. Type V members are brown-skinned and black-haired, for example North Africans and Indians belong to skin type V. People with skin type VI have black skin and black hair, typically Africans belong to skin type VI. Skin cancer is rare among these skin types.