Why does sunbathing cause cancer

What is at stake? This damage is cumulative, starting from the very first tan. Your Health One in five Americans will develop skin cancer by the age of Worldwide, there are more skin cancer cases due to indoor tanning than there are lung cancer cases due to smoking.

Your Appearance Tanning changes and ages your skin. If you do develop skin cancer, you run the risk of further, sometimes unsightly changes to your appearance. Tanning facts and risks. Tanning FAQs. Are tanning beds as harmful as the sun?

Is tanning a good way to get vitamin D? There are many options that can give you a bronzed look, but you still need sun protection! To protect against the sun, apply sunscreen to uncovered skin 30 minutes before going outside and again every two hours or after swimming or sweating.

The sun, sunlamps, and tanning booths all give off ultraviolet UV radiation. Exposure to UV radiation causes early aging of the skin and damage that can lead to skin cancer.

People of all ages and skin tones should limit the amount of time they spend in the sun, especially between mid-morning and late afternoon, and avoid other sources of UV radiation, such as tanning beds. Keep in mind that UV radiation is reflected by sand, water, snow, and ice and can go through windshields and windows.

Even though skin cancer is more common among people with a light skin tone, people of all skin tones can develop skin cancer, including those with dark skin.

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A to Z List of Cancer Drugs. Questions to Ask about Your Treatment. Feelings and Cancer. Adjusting to Cancer. Day-to-Day Life. Support for Caregivers. Questions to Ask About Cancer. Choices for Care. Talking about Your Advanced Cancer. It lasts from several weeks to months, and is maintained by repeated exposure to sunlight. With delayed tanning, the skin increases its production and distribution of dark pigment.

The skin also becomes thicker. These changes can follow sunburning or develop gradually over a long period of repeated brief exposures to sunlight. Some people burn easily after the first hour of sun exposure following winter or any period away from the sun. Other people, especially those with dark skin, rarely burn. This difference in reaction makes it possible to classify skin into one of six different types see Table 2.

The risk of skin cancer from the sun generally follows the same pattern. Darker skinned people have lower risk of sun-induced skin cancer. The person most prone to skin cancer caused by sunlight tans poorly and suffers sunburn easily. For reasons not completely understood, people with Celtic heritage Irish, Scottish or Northern European have increased risk of skin cancer from the sun. Genetic diseases that affect the skin can also increase the risk.

For example, albinism, a genetic condition which prevents the production of normal skin pigments, makes the skin sensitive to ultraviolet light. Exposure to certain chemicals can increase the skin's sensitivity to ultraviolet light through a process called photosensitization. Examples of such chemicals include:. Check with your physician or pharmacist if you suspect abnormal or severe reaction to sun exposure after taking new medication. However, simple skin contact with psoralens, which are found in figs, parsnips, citrus plants, or mouldy celery, can make the skin more susceptible to sunburns in some individuals.

Experimental studies show that chemicals called "promoters" can increase the cancer-causing ability of ultraviolet radiation. On the other hand, ultraviolet radiation itself can act as a promoter. In particular, ultraviolet radiation UVR can increase the cancer-causing ability of chemicals from coal tar and coal tar pitches.

The damaging effects of ultraviolet radiation accumulate over the years. In general, the risk of developing skin cancer increases with the amount of time spent under the sun and the intensity of radiation.

The intensity of radiation varies according to the season of the year, time of day, geographic location latitude , elevation above sea level, reflection from surfaces e. Recent studies have focused on the effects of intermittent short-term, occasional sun exposure in comparison to chronic long-term exposure. It appears that the type of exposure may influence the type of cancer that develops.

For example, intermittent solar exposure may be an important factor leading to the onset of basal cell carcinoma of the skin. Childhood sun exposure may also play an important part in the development of these cancers later in adult life. The pattern for cutaneous melanoma is similar to that for basal cell carcinoma. In contrast, the relationship between squamous cell carcinoma and solar UVR appears to be quite different.

For squamous cell tumours, high levels of chronic occupational sunlight exposure, especially in the 10 years prior to diagnosis, results in an elevated risk for this cancer in the highest exposure group.

It can go to the mid-teens at midday in the tropics. In Canada the UV Index is categorized into low 2 or less , moderate between 3 and 5 , high between 6 and 7 , very high between 8 and 10 and extreme greater than The human health effects and precautions relating to the UV Index are summarized in the following table.

All outdoor workers potentially exposed to the sun's ultraviolet radiation are at risk, including:. Skin cancer is the result of decades of exposure to the sun. It is important to be aware of the risks and take precautions while under the sun from as early in life as possible. Approaches to prevent skin cancer include:. In the winter time, it may be advisable to the above precautions when exposed to sun for prolonged periods, especially in the presence of snow or at high altitudes.

Workers should avoid unnecessary exposure to the sun, especially to the intense midday rays between a. If possible, people should plan outdoor work for early morning or late afternoon, and work in the shade as much as possible. Umbrellas, buildings, trees, canopies, etc. Work, and take breaks in the shade when ever possible. Set up shade structures when shade is not available. In addition, water, white sand or concrete, snow, and ice can reflect from around 10 percent to 85 percent of the sun's ultraviolet radiation.

Skin may require extra protection against these indirect, reflected rays. Occasional mistakes during the repair of this damage leads to the incorporation of wrong bases into the genetic material. These types of mistakes often result in mutation leading to loss or inappropriate expression of affected genes.

Recent studies indicate that genetic alterations in the p53 tumor suppressor gene play an important role in the development of skin cancer. Unrepaired photoproducts in the p53 gene are transformed into mutations thereby initiating the process of carcinogenesis.

Following repeated exposures to UV, keratinocytes carrying p53 mutations acquire a growth advantage by virtue of their increased resistance to apoptosis. Several studies have shown that UV induces unique types of p53 mutations in skin cancers at a high frequency that are not commonly found in other types of human cancer.

Analogous to human skin cancers, skin cancers induced in laboratory mice by UV radiation also display UV signature p53 mutations at a high frequency. More interestingly, p53 mutations are also present in sun-exposed skin and it can serve as an indicator of prior solar exposure in humans. It has been shown that p53 mutations in mouse skin arise as early as one week of chronic UV-irradiation and the frequency of p53 mutations reach a maximum at 4—8 week of UV exposure.