During summer the sunlight, heat and humidity seem to take on a different dimension. Swimming pools, rivers and beaches assume irresistible appeal.

Black skin is not exempt

Many of us believe that as black people with our protective skin pigment, melanin, we are immune to damaging effects of sunlight like sunburn, skin cancers and premature ageing of skin. It's true that melanin absorbs ultraviolet rays in sunlight, preventing them from penetrating deeper and although darker skin can withstand exposure to the sun for longer periods than lighter skin, the protection which melanin offers is limited.

Nobody, black or white, is exempt from sun damage. Lack of protection, plus late detection of skin cancers can lead to a high risk of dying from the condition. But most of us here in Jamaica do not wear sun protection.

Fry now, pay later

Years ago, I saw a sunscreen advertisement which read, 'Fry now, pay later', correctly suggesting that eventually there are negative effects associated with prolonged exposure to direct sunlight. The rays are responsible for skin conditions like solar urticaria and porphyrias. Solar radiation aggravates skin lesions in lupus and in other skin conditions. Sun protection is a smart precaution for everyone, particularly children.

Don't leave home without it

Sun protection involves limiting the time spent in direct sunlight, using screens (tints) on windows, wearing protective clothing and, of course, wearing sunscreen products.

How sunscreens work

Sunscreens work to prevent harmful ultraviolet (UV) rays, that is, UVA and UVB from penetrating the skin. In excess, UVA rays tan skin while UVB rays cause sunburn. Sunscreens absorb some UVB radiation so less of it reaches into the skin. Other sunscreens reflect UV rays (especially UVA) away from skin, and are called sunblocks.

Sun Protection Factor (SPF)

The sunscreen's SPF is a number which describes the degree of protection it offers against UVB. Theoretically, a sunscreen with SPF of 15 indicates that the wearer of that sunscreen may remain 15 times longer in the sun without burning when compared to someone wearing no sunscreen. But time of day, location, weather conditions and amount of sunscreen applied can affect the accuracy of this calculation. Nonetheless, the higher the sunscreen's SPF, the greater the protection it offers.

What to look for

Sunscreen should offer protection against UVA and UVB. Look for an absorber like octinoxate, octyl-salicylate, octocrylene, avobenzone, oxybenzone, and a reflector like titanium dioxide or zinc oxide among ingredients.

Consider getting SPF of 30 or higher.

If you plan to venture into water, get a water-resistant or waterproof product.

Sample the product on the skin to determine how it looks and feels. Having found the ideal sunscreen, apply it 20 minutes before going out, and thickly and frequently (like every other hour) when staying outdoors for long. Reapply the sunscreen after swimming, bathing, perspiring heavily or after drying the skin with a towel.

Dahlia McDaniel is a pharmacist and final-year doctoral candidate in public health at the University of London; email: yourhealth@gleanerjm.com.