The incidence of too much sunlight on the skin is responsible for the occurrence of many diseases and skin problems, among which we can include, for example: aging, dry skin, the appearance of wrinkles, bags under the eyes, crow's feet, spots, or skin cancers.

Protecting the skin against the sun's rays is necessary throughout the year but is especially required in summer when the sun's rays are stronger and when we expose the skin for much longer, such as as we walk around the town, stroll in the countryside or when we are bathing or sunbathing on the beach.

According to the World Health Organization, in 2005, some 100,000 people died of cancer - which represents more than 28% of total deaths. Of these nearly 8% of them did so for skin cancer.

 

Why sunlight can be bad for skin?

The sun's ultraviolet rays are mainly responsible for the damage caused to the skin. The effects of these rays are cumulative, so that the radiation that skin accumulates over time is responsible for the development of melanoma, the most common type of skin cancer which every day is more widespread. There are different types of ultraviolet rays. The main ones are:

- The long-wave ultraviolet rays, called UVA, which have a wavelength between 400 and 320 nanometers (nm)

- The ultraviolet B or medium wave ultraviolet (UVB), with a wavelength between 320 and 280 nm.

- The ultraviolet C or short-wave ultraviolet (UVC), with a wavelength between 200 and 280 nm.

UVA rays are responsible for tanning but they also are responsible for the appearance of erythema, decreased body defenses or the appearance of melanomas by accumulation of prolonged radiation exposure. These rays are also responsible for the appearance of wrinkles and skin spots.

UVB rays are even more pernicious: they are the main cause of sunburn, skin aging and skin cancer.

Ultraviolet C rays are very short waves that are filtered by the ozone layer. In theory, they should not reach the ground , but we all know that the ozone layer is not at its best nowadays, so that this kind of rays could severely damage our health.

Ultraviolet rays can also affect the health of the eyes, causing cataracts or problems , such as vision loss or macular degeneration, so it is appropriate to protect our eyes with suitable sunglasses in summer, especially when we are in places where the ground or the walls are highly reflective, such as beach sand or white walls.

How to know which protection to use?

In most countries, on television or in newspapers, one can access to the UV index which is what tells us the average risk values against sun exposure. These exposure levels may pose a low risk, a moderate risk , a high or extremely high risk .

This type of index is an advice to avoid too long exposure or, if you decide to expose yourself , you should take some sort of protection.

UV index
Type	Value	Effective protection
Low	1, 2	No protection needed . You can act freely outdoors.
Moderate	3, 4	Protection is required. Stand in the shade during peak hours There is a well-known slogan that Australians have been created to reduce skin cancers that says: "Slip on a shirt, slop on sunscreen, slap on a hat = get into a shirt, use sunscreen and put on the hat"
High	5, 6, 7
Very high	8, 9,10	Avoid peak radiation hours, sure to seek shade and protect clothes necessarily, sunscreen and hat.
Extreme	11 or more

It is very suitable for you to use a sunscreen with a Sun Protection Factor according to your type of skin and the time you are going to be in contact with sun rays. For more details about which Sun Protection Factor to use, you can find more information on the chapter " Types of skin" in the listing above.