EXPOSURE TO THE SUN
Interview to Dr Adalberto Fabbriconi
When we think about summer or vacations the first association we make is the sun.
Our relationship with the sun is and should be of friendship, but we do not often pay attention to the risks that tanning may occur on our skin (burnings, erythema) or to the alterations that show up after few years, like premature aging of the skin or cutaneous tumors.
The exposure to the sun at the seaside, mountain or city must be reasonably based on your own phototype, which is the characteristic of your skin.
Discover the phototype together:
We are not all equal under the sun, it all depends on our phototype which is defined by:
- color of the skin
- color of hair
- predisposition to the appearance of erythema
- tanning
They have been classified 6 various phototype
Table of Phototype |
Phototype |
hair |
complexion |
erythema |
tanning |
1 |
red |
pale |
constant +++ |
not |
2 |
blonde |
light |
constant ++ |
lightly tanning |
3 |
brunette |
light |
sometimes |
lightly tanning |
4 |
tawny |
olive |
rare |
dark |
5 |
black |
olive |
exceptional |
very dark |
6 |
black |
black |
never |
black |
In order to choose the more suitable sunscreen for your type of skin is important to know your own phototype, but it is equally important to consider the intensity of the sun and the conditions of exposure (in the mountain the amount of ultraviolet rays increases of the 4% every 300m).
The superficial light and the ultraviolet rays can reach the skin also being reflected on different surfaces so that you can be affected by erythema under a cloudy sky or under the beach umbrella.
The protection factor
The protection factor (indicated as SPF –Sun Protection Factor-) expresses the ability of a solar protector to stop the solar radiation, above all the UVB type. This parameter is the relationship between the necessary energy used to produce the appearance of a reddening (erythema) on the skin protected by a product and the one necessary to obtain the same answer without protection.
Based on the SPF, products are subdivided in five groups:
- from 2 to 6
- from 8 to 12
- from 15 to 25
- from 30 to 50
- beyond 50
The number that indicates the SPF however remains an approximate indication of the protecting ability: in fact it is influenced by the vehicle, the concentration and the solubility of the active principle, the type of skin and the intensity of the radiations that proportionally increases with the altitude over the sea level.
For what concerns the protection against UVA there is not a standardized method yet, but usually we make reference to two particular elements: the immediate and persisten pigmentation.
It is important however that the product protects against both UVA and UVB.
Talking about the filter...
Every solar product differs not only based on its SFP, but also thank to the presence of physicalscreen and chemical filters.
THE PHYSICAL SCREEN
The physical screen are mineral substance as titanium dioxide and zinc oxide.
These substances oppose a real screen to radiations (especially UVB).
They are presented as white dusts, chemically inert but with a very strong covering power: their mechanism of action consists in the reflection of radiations.
THE CHEMICAL FILTERS
These are a series of substances whose chemical structure is able to absorb energy.
Today there are filters of last generation that allow a complete cover of ultraviolet spectrum (UVB, long and short UVA) and, thanks to their great molecular dimensions, they act like physical screens reflecting the radiations.
Resistance to Water
When we choose a solar cream we need to consider the resistance to water and therefore to sweat. On the wrapping we can find the “water resistant”, that is to say that the index of protection remains in the same interval of values indicated on the label after 2 baths, or “water proof”, which means that you will have those conditions after 4 baths.
How to choose a solar product
In order to choose a solar product we must estimate:
- own phototype
- age of the person (children and old people demand an elevated factor of protection)
- locality in which the exposure will take place
- the presence of eventual reflecting surfaces (reflected radiation or Albedo)
- time and duration of exposure
- eventual drug assumption
- the presence of pathologies that can get worse in sun presence
An advice from the doctor can help to understand the most suitable protection factor.
The ten rules
Here you are the ten fundamental rules in order not to make the sun a danger for your skin:
- apply the solar products before going out, repeating the application frequently, in particular after every bath.
- in the first days of exposure do not to take more than 45 minutes of sun (20 minutes of intense sun): beyond this limit the melanociti are saturated and they do not produce anymore melanin.
- avoid to expose between 12 p.m. and 4 p.m. when the solar radiation is at the maximum of its intensity.
- do not expose children under 3 during the hours of more and less intense solar radiation, apply a resistant water product with a high index of protection
- do not forget that the sunstrokes do not occur only on the beach: for whichever open air activity the best thing to do is protect.
- pay attention at the altitude, to the cloudy sky, to the fresh wind and reflecting surfaces (snow, sand, and water): factors that increase the danger.
- wear hat and sunglasses with approved lens to filter the UVA and UVB. Protect the children with dry T-shirt: a wet T-shirt makes the UV filter.
- dry up yourself very well after every bath: the effect mirror of drops favors sunstrokes and reduces the effectiveness of solar products.
- drink a lot of water and do it often because the sun dehydrates. Pay attention to old people, who have a reduced feeling of thirst and to children, who need plenty of water because their thermoregulation is less effective.
- for any doubt, perplexity ask your doctor for an advice.
Good vacations!
Dr. Adalberto Fabbriconi
PHARMACY BANDI - MILAN
Via Rovereto 14 (ang. V.le Monza)
versione italiana