What Are Sunscreens? Sunscreens are products which contain several ingredients that help to prevent the ultraviolet (UV) radiations of sun from reaching the skin. Two types of ultraviolet radiation, UVA and UVB, damage the skin. Sunscreens vary in their ability to protect against UVA and UVB.
General information:
Sunlight consists of two types of harmful rays that reach the earth — UVA rays and UVB rays. Overexposure to either can lead to harmful skin effects. Here’s what each of these rays do:
UVA rays (or aging rays) can prematurely age your skin, causing wrinkles and age spots, and can pass through window glass.
UVB rays (or burning rays) are the primary cause of sunburn and are blocked by window glass.
UVA rays penetrate deeper into the skin, damaging the middle layer (the dermis). The dermis contains the elastic tissues that keep the skin stretchy. UVA rays therefore have the effect of ageing the skin and causing wrinkles. UVB rays are absorbed by the top layer of skin (the epidermis). This causes sun tanning but also burning.
Both UVA and UVB rays increase your risk of developing skin cancer. Getting sun burnt is therefore a warning sign that you are putting yourself at risk.
Melanin is the coloured pigment in our skins. When skin is exposed to sunlight, more melanin is produced to help protect the skin against the UV rays. This makes the skin darker – what people refer to as a suntan. Although melanin stops your skin burning so easily, it does not prevent the harmful effects of UV rays.
Harmful effects of sunlight: The effects of sunlight are not same in every person. It varies from person to person depending on the skin photo-type, race, occupation, lifestyle, geographic factors (like altitude and latitude), age, genetic makeup of the person and any metabolic disorder (like Hartnup’s disease). Therefore the effect of same amount, duration and type of exposure will be different in every individual and so should the treatment.
Among the harmful effects of sunlight sunburn is important which is characterized by redness, pain, warmth and swelling.
UV rays can cause tanning which can be of two types:
(a) Immediate pigment darkening (IPD)- begins soon after exposure to sunlight and lasts upto 2 hours which is due to oxidation of existing melanin and redistribution of melanin within the outer layer of skin.
(b) Delayed tanning which appears after 48-72 hrs and because of new melanin synthesis, increase in size of melanocytes and activation of quiescent melanocytes.
Exposure to sunlight causes suppression of immunity, skin becomes hypersensitive to sunlight leading to sunlight allergy called PMLE- Polymorphous Light Eruption.
Dreaded effect of prolonged exposure to sunlight is, Skin cancer
What are the types of sunscreen?
Sunscreens are divided into two categories-
Physical sunscreens and Chemical sunscreens.
Physical sunscreens: scatter the sunlight and are capable of blocking UVA, UVB and visible light and being chemically inert do not cause allergic reactions but are cosmetically not well accepted. Example:Titanium dioxide, Magnesium oxide, Magnesium silicate and Zinc oxide. Now micronized forms of Titanium dioxide and Zinc oxide are also available which are more acceptable cosmetically.
Chemical sunscreens: absorb a specific wavelength of light; cosmetically they are better than physical sunscreens.
Chemical sunscreens are divided into UVA and UVB blockers.
UVA Blockers – Oxybenzone, Methyl anthranilate, Avobenzone.
UVB Blockers – Oxybenzone, Padimate –O, Cinnamates, Octyl salicylate, Phenyl bezamidazole sulphonic acid.
Why sunscreens are to be used?
Too much exposure to sunlight is harmful and can damage the skin. Some of this damage is short-term (temporary), such as sunburn. However, allowing your skin to burn can lead to future problems, such as skin cancer due to long-term skin damage.
Who needs sunscreen?
Everyone over the age of six months should use a sunscreen daily.
Even those who work inside are exposed to ultraviolet radiation for brief periods throughout the day, from TV screen, computer monitor, tube lights and especially if they work near windows, which generally filter out UVB but not UVA rays.
Sunscreen use can help prevent skin cancer, premature aging of skin by protecting you from the sun’s harmful ultraviolet rays.
When and Where to Use Sun Protection?
Even when it is cloudy; clouds and haze do not block sunlight
Near water, snow, ice, and sand; UV is reflected and comes under the hat or umbrella to the skin.
What sunscreen should I use?
Sunscreens that offer the following should be used:
Broad-spectrum protection (protects against UVA and UVB rays)
Sun Protection Factor (SPF) 30 or higher
Water resistance
A sunscreen that offers the above helps to protect your skin from sunburn, early skin aging and skin cancer. However, sunscreen alone cannot fully protect you. In addition to wearing sunscreen, it is recommended to follow these advises:
Seek shade when appropriate, remembering that the sun’s rays are strongest between 10 a.m. and 2 p.m.
Wear protective clothing (thick clothes-not transparent), such as a long-sleeved shirt, pants, salvar kameez, dupatta, scarf, cotton gloves, a wide-brimmed hat, full face helmet, and sunglasses, when possible.
Use extra caution near water, snow and sand as they reflect the damaging rays of the sun, which can increase your chance of sunburn.
Get vitamin D safely through a healthy diet that may include vitamin supplements. Don’t seek the sun.
- Hat: A hat that optimally protects from the sun has a 4-inch brim all the way around. Test the shade given by your hat by tilting your head to see how much of your cheeks get into the sun. Straw hats and baseball caps with the hole in the back do not give enough protection to bald heads—but are better than nothing.
Avoid tanning beds. Ultraviolet light from the sun and tanning beds can cause skin cancer and wrinkling. If you want to look tan, you may wish to use a self-tanning product, but continue to use sunscreen with it.
SPF: Sun Protection Factor – is a measure of a sunscreen’s ability to prevent UVB from damaging the skin. Here’s how it works: If it takes 20 minutes for your unprotected skin to start turning red, using an SPF 15 sunscreen theoretically prevents reddening 15 times longer – about five hours. Most sunscreens with an SPF of 15 or higher do an excellent job of protecting against UVB.
When should I use sunscreen?
Every day if you will be outside. The sun emits harmful UV rays year-round. Even on cloudy days, up to 80 percent of the sun’s harmful UV rays can penetrate your skin.
Snow, sand, and water increase the need for sunscreen because they reflect the sun’s rays more
How much sunscreen should I use, and how often should I apply it?
Use enough sunscreen to generously coat all skin that will be not be covered by clothing. Ask yourself, “Will my face, ears, arms or hands be covered by clothing?” If not, apply sunscreen.
Apply sunscreen to dry skin 20-30 minutes BEFORE going outdoors.
Apply 2mg/cm2 (5ml-face, neck, each arm, leg). 1ounce (30gm) for whole body.
Apply enough sunscreen to cover the skin that will be exposed. For most people this is the equivalent of two teaspoons of cream for the head, neck and arms. For the whole body while wearing a swimming suit, this would be around two tablespoons.
To protect your lips, apply a lip balm or lipstick that contains sunscreen with an SPF of 30 or higher.
Re-apply frequently, at least every two hours, and always after swimming, toweling yourself dry or excessive sweating (even those that are labeled waterproof).
What type of sunscreen should I use?
Sunscreen with broad-spectrum (UVA and UVB) protection, with an SPF of 30 or higher and is water resistant is most recommended.
The kind of sunscreen you use may vary depending on the area of the body to be protected. Available sunscreen options include lotions, creams, gels, wax sticks
Creams and water based gels, lotions are best for dry skin and the face.
Gels are good for hairy areas, such as the scalp or male chest.
Sticks are good to use around the eyes.
Will Sun Protection Deprive Me of Vitamin D?
Regular use of sunscreen does not greatly decrease vitamin D levels over time. Sunscreen tested in laboratory conditions does block vitamin D production, however regular use in real life has been shown to have little effect on vitamin D levels. This is because people don’t usually use enough sunscreen, so UV can still reach the skin. Those people who use sunscreen also tend to spend more time in the sun.
Most people get an adequate amount of vitamin D in their diets. If you are concerned about not getting enough vitamin D, consult your dermatologist/physician and consider taking vitamin D supplement .Also, vitamin D is available in food such as fatty fish like salmon, tuna & mackerel and egg yolk, as well as enriched milk and orange juice, cereal.