GD — Society for Dermopharmacy
 |
Issue 2 (2001) |
Dermocosmetics
Sun Protection Preparations
High Protection factors convey
the
misleading Impression of Safety
It is true that sun
protection agents can protect from sunburn, a fact which has been known
for a long time. However, an investigation undertaken by European oncologists
has revealed that this can under no circumstances be treated as an equivalent
of a hundred percent protection from skin cancer. Accordingly mainly persons
with a fair complexion, using sun screen agents, had a nearly sixty percent
higher melanoma risk than control persons not using these agents. The
explanation for this paradox: persons using sun protection agents stay
longer in the sun, having a safe conscience, than the ones dispensing
with it. In particular, preparations with high light protection factors
(LPF) eliminate the warning signal which the sunburn ultimately signifies.
According to the statistics every second German citizen has to reckon today with getting skin cancer, in fact, namely 31 percent a basalioma, 18 percent a prickle-cell carcinoma and 1,2 percent a malignant melanoma. The best UV-protection can be achieved according to recommendations of the Radiation Protection Commission by wearing appropriate clothing, good sunglasses and the avoiding of the sun. Concerning clothing it should be considered that mainly light-colored and wet textiles are pervious to ultraviolet rays. The protective effect from ultraviolet rays can be enhanced by using detergents which give off an ultraviolet absorber to the textile fiber during the washing process and thus increase the ultraviolet impermeability of the garment from washing cycle to washing cycle.
If sun protection is additionally used, it should have a sufficient protection factor and be effective in the UVB as well as the UVA sector. Men should equally be convinced of the necessity of using a sun protection if necessary as they often take the opinion that their skin, robust by nature, does not need such protection. The consequence is that men die more frequently of skin cancer than women although they come down with the disease more rarely.
Ultraviolet index should
be part of the weather report
 Dr. Nicole Chauvet |
In order to sensitize the population for the dangers emanating from an
excessive UV-exposition and for the necessity of protective measures,
the WHO urges the national health authorities all over the world to perform
an increased application of the UV index (UVI) introduced in 1994. According
to the opinion of the WHO, the forecast of the UVI should be part of the
daily weather report in newspapers, radio and television. Threshold value
for the daily sun stress is in the WHO's view a minimal erythema dose
(MED) of 0,3.
In Germany, the UVI is communicated by the German Weather Service. The
latter publishes daily forecasts which may read for example as follows:
"the forecast until this evening: UV-index 6. Sunburn at unprotected
skin may already arise after 25 minutes' stay in the sun. Protective measures
are required". Corresponding information can also be obtained telephonically
or in the Internet (www.bfs.de/uvi/prognose.htm) from the Federal Office
for Radiation Protection. The UVI values in Germany are from 1 to 8, in
the mountains up to 9. In the tropics, average values of 12 can be reached.
Recommendable to divide
indicated light protection factor in half
Regarding the indicated light protection factors of sun protection preparations it has to be taken into account that they refer to the MED, i.e. the radiation dose until the emergence of first signs of a sunburn and not to the radiation dose for an increased skin cancer risk which is significantly lower. Moreover, the factors have been determined on the basis of idealized experimental conditions and represent average values with a, at times significant mean variation. Furthermore, the product quantities applied for the determination of the light protection factor are on average approximately twice as high as the quantities applied in reality. Solely due to this reason it is recommendable to cut in half the light protection factor indicated for sun protection agents when calculating the permitted radiation time as precautionary measure.
 Despite educational campaigns many people still spend too much time in the sun. Although being protected by a sun protection agent from sunburn they are exposed to an increased skin cancer risk. |
The same problem poses for the question of the water-resistance of sun protection agents. The tests to which attributions as "water-resistant" or "very water-resistent" refer are mostly carried out by using fresh water, although salt water removes the product more easily from the skin. Also the product abrasion by contact of skin with towels, sand and wind is only insufficiently considered in the examination of the water resistance. Therefore, in order to ensure the sun protection there is no other choice but to cut the indicated light protection factor in half.
Prospects for the future
Target for the future has to be a developing of sun protection agents which are sufficiently stable and thus equally effective after an extensive UV-exposition as shortly after the application. Desirable would be sun protection creams with a combined spontaneous and retarded effect - so that the effective ingredients develop in the epidermis step by step as small parachutes in order to form the natural UV-protection of skin and moreover a second prolonged shield. (nch/jk)
| Sun
protection also after sunbathing? The dermatologist professor Dr. med. Jean Krutmann, Düsseldorf and the pharmaceutical technologist Dr. Peter M. Hansen, Bad Vilbel report in an article in the recently published Deutsche Apothekerzeitung (German pharmacist newspaper) (No. 21, pages 67-71 2001) that the skin can also be protected after sunbathing. The authors - both members of the department Dermocosmetics of the GD describe in this article an after-sun-lotion (Ladival® med) on the basis of a DNA-repair enzyme (photolyase) which is normally not present in skin. By a topical application of this enzyme, the restoration of UV-B-induced DNA-damages, especially by retransformation of cylobutan-pyrimidin-dimers in thymine-monomers is enhanced. Hereby immunosuppressive effects which are decisively involved in the developing of skin cancer are avoided. The authors emphasize, however, that this innovative after-sun concept does not replace the use of sun protection preparations. (jk) |
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