According to the Cancer Council of Australia, prolonged exposure of UV radiation from the sun or other sources that emit UV radiation (such as sun beds and solar lamps etc.) is the main etiologic agent (about 99% of non-melanoma skin cancer) in the development of skin cancers.
Before we jump into explaining how we can safeguard yourself against skin cancer, it is important to first understand the basics of UV radiation and the harmful effects it has on our skin.
What is UV radiation?
UV radiation is a form of electromagnetic radiation that is emitted from the sun and equipment such as solar lamp and tanning beds.
There are 3 main types of UV radiation:
UVA rays are the main culprit for causing skin ageing by inflicting indirect damage to the skin cells. UVA rays are associated with long-term skin damage and premature ageing. Visible signs of ageing such as wrinkles and fine lines are mainly caused by UVA rays. They are also thought to play a role in some skin cancers.
Although less intense than UVB, it penetrates the skin more deeply, causing genetic damage to the innermost layer of the skin. UVA can penetrate glass and windows.
UVB rays are mainly responsible for damaging the skin cells and cause sunburns. It penetrates and damages the outermost layer of the skin. Scientists also found that they are the main cause of most skin cancers. Intensity of UVB is the strongest between 10am and 3pm.
Fortunately, UVB can be filtered out and they do not penetrate glass.
UVC rays don’t reach the earth surface because they react with the ozone in the atmosphere. This means that we don’t suffer from the adverse effects from UVC rays. However, man-made equipment that generate UV radiation can emit UVC rays. It is not a significant risk factor for skin cancer as there is negligible exposure to them.
What happens when you are exposed to prolonged UV rays
Prolonged exposure to UV rays without applying sunscreen may cause the skin to produce more melanin, darkening the skin over time. Melanin is an important protective pigment found in the skin. Its main function is to block harmful UV radiation from damaging your skin and potentially causing skin cancer.
The darkening of melanin is what gives you the sun-kissed appearance everyone seeks. However, when the melanin is unable to protect you from the UV rays, you end up getting a sunburn.
Repeated prolonged exposure to UV rays may result in one or more of the following outcomes:
- Wrinkles and fine lines
- Skin pigmentation and discoloration such as age spots, freckles, liver spots and moles
- Dry, leathery skin due to depletion of collagen and premature ageing
- Formation of solar keratoses which may turn into skin cancer
UV rays can also long-term damage the eyes. Clinical studies have shown that UVB rays can damage the cornea and lens of the eyes. Overexposure to UVB may also damage the retina. Neither UVA and UVB has been shown to be beneficial for the eyes so optimal protection is important.
UV rays and Skin cancer
It is an established fact that UV radiation is a proven cause of basal cell carcinoma and squamous cell carcinoma. These common form of skin cancers are usually found on areas that are frequently exposed to the sun.
The risk of getting skin cancer increases significantly if UV exposure often leads to sunburn. Recent studies have shown that UV rays may alter a gene that suppresses tumors, causing it to develop into skin cancer.
How do I detect skin cancer?
Skin cancer is more prevalent among the Caucasian population. Although Asians generally seem to be relatively protected from skin cancer, incidence rates of non-melanoma skin cancers have been increasing the past few decades, especially in Japan.
Some warning signs you need to look out for:
- Formation of unusual moles, sores, blisters or blemishes
- Gradual change in the size, shape and color of the new pigment on the skin
- Spread of dark pigment from the border of the spot
- Redness and inflammation beyond the border of the pigment
- Pain, tenderness and itch on the spot
It can sometimes be difficult to differentiate between a normal mole and melanoma. Be sure to visit your doctor when you are unsure of the new mole or pigment on your skin.
How do I protect myself from UV radiation?
There are several steps you can take to protect yourself from overexposure to the harmful UV rays:
USE A SUNSCREEN Choose a broad-spectrum sunscreen with at least SPF50. The “broad-spectrum” protection filters out UVA radiation from the sun. SPF, or Sun Protection Factor protects you from UVB radiation.
We may think that the higher the SPF, the more protection it provides. To put things in perspective, SPF50 filters out 98% of UVB and SPF100 filters out 99%. The difference is very small. In fact, doctors have noted that sunscreen with high SPF gives people a false sense of security. People who use high SPF products think that they can stay out in the sun for a longer period of time, which defeats the purpose.
AVOID CERTAIN HOURS OF EXPOSURE The hottest part of the day is between 10am and 3pm. Try to avoid exposing yourself to the strongest sun’s rays during that time.
WEAR PROTECTIVE GEAR Make sure you are sufficiently clothed when you go outdoors. Wear long-sleeved shirts, long pants, hat and sunglasses to physically shield yourself from the sun.
How to get rid of unsightly pigmentation
The earlier you treat, the easier it is to get rid of it. If left untreated, the dark pigments may move deeper into the skin, making it more difficult to treat.
For a start, your doctor may prescribe topical pigmentation cream that contains powerful active ingredients like vitamin C, tranexamic acid, or kojic acid to reduce hyperpigmentation.
Other active ingredients in OTC pigmentation creams you can look out for include hydroquinone, licorice root and ReviWhite.
If topical application is not enough, your doctor may recommend pigmentation laser treatments such as PicoSure Laser, Sylfirm, or Dual Yellow Laser. These lasers deliver high energy, focused beams to shatter pigments deep in the skin layer.
Although the sun has far-reaching negative impact on our health, the good news is that a lot of these risks can be mitigated by putting in effort to protect yourself from them.