Get Sun Smart

Dr. Sihan Waghid, Dermatologist at Melomed Mitchells Plain Hospital

What are UVA and UVB?
UVA and UVB are radiation from the sun that affects the human skin. UVB radiation is the main cause of sunburn, whereas UVA radiation penetrates deeper into the skin, causing premature aging. Visible light, particularly high-energy blue or violet light, also impacts skin health, contributing to pigmentary disorders, especially in medium to dark skin tones. Tinted sunscreens containing iron oxides are effective against visible light and are recommended for those with hyperpigmentation.

How does SPF work?
A sunscreen or sunblock absorbs or reflects the sun’s radiation. Sun Protection Factor (SPF) indicates how long a person can be exposed to sunlight before burning with sunscreen compared to without. You can calculate it: take the time it would usually take you to start burning without sunscreen and multiply it by the SPF. For example, if it takes you 10 minutes to start burning, an SPF 15 sunscreen will protect you for 10 x 15 minutes = 150 minutes. Other factors that may affect how fast you start burning are:
• The amount of sunscreen applied (using the “2-finger method” for each body part ensures effective coverage),
• Your skin type,
• The frequency of sunscreen reapplication,
• Activities, such as swimming and sports.

The higher the SPF, the better?
A higher SPF only provides a small percentage more UVB protection but does enhance UVA protection. Since many people underapply sunscreen, using SPF 50 or higher is often recommended to compensate. However, even with sunscreen, you shouldn’t stay in the sun all day.

How do I protect my kids?
Keep children, especially those under six months, out of direct sunlight, as they are especially vulnerable to UV damage. When exposure is unavoidable, use high-SPF sunscreen on small areas, encourage full-body swimsuits, broad-brimmed hats, and sunglasses with UV protection.

What about dark skin?
People with darker skin tones also need sun protection, as they are still at risk for sun-induced skin damage, photoaging, and skin cancer. Tinted sunscreens can protect against both UV and visible light, helping prevent hyperpigmentation in medium to dark skin tones.

How do I get the most out of my sunscreen?
• Always use at least SPF 30 with both UVB and UVA protection.
• Check the expiry date – old sunscreen won’t be effective.
• Keep sunscreen products in a cool place, out of direct sunlight.
• Shake the bottle before use.
• Apply the lotion generously and evenly, 30 minutes before heading outside.
• Reapply sunscreen after swimming, perspiring, exercise, and towel-drying.

What about protecting the eyes?
Eye protection is crucial. UV exposure can lead to eye conditions like pterygium and cataracts. Look for wraparound sunglasses with 100% UV resistance, or consider variable-tint lenses to cut out UV rays.

And if you don’t…
Excessive sun exposure, especially with blistering sunburn episodes, is a major risk factor for melanoma, the most dangerous and lethal of all skin cancers. Skin cancer is the most common form of human cancer, and over 90% of cases are caused by sun exposure.

The ten golden rules
1. If your shadow is longer than you, stay out of the sun.
2. UV rays penetrate clouds, so treat cloudy days as sunny.
3. Cover up with a broad-brimmed hat and long-sleeved clothing.
4. Apply an SPF 30+ sunscreen to any exposed skin.
5. Keep children under the age of one out of the sun.
6. See your doctor or dermatologist immediately if you become aware of any changes in moles or new irregular patches.
7. Avoid sunburn, and even with sunscreen, don’t stay in the sun longer than necessary.
8. Avoid sunbeds at all costs.
9. Remember that early melanoma detection offers the best chance for a complete cure.
10. Make sun safety a habit!

THE FACTS - The ABCDs of melanoma
A = Asymmetry
Melanomas are often asymmetrical, whereas moles are generally symmetrical.
B = Border
Melanomas frequently have irregular, uneven borders with scalloped edging. Benign moles usually have smooth, even borders.
C = Colour
Common moles are usually a single shade of brown or black. Melanomas are often multicoloured, with shades of brown, black, red, white, grey, pink, or blue.
D = Diameter
Benign moles are usually (but not always) less than 6mm in diameter, whereas melanomas tend to be larger.

Even though we use this ABCD criteria as a guideline, if you notice any mole changing in appearance—whether in shape, colour, size, or texture—consult a dermatologist. Early detection can be life-saving.