Reflections on Skin Damage That Is Caused by Albedo

Every skin photobiologist hopes consumers are aware of the danger of exposure to solar radiation and behave accordingly. For the time being, the dream is more of a nightmare: people still undergo extreme sunbathing to obtain a tan, be it on a sunny beach or in a tan parlor. If their phototype is 1 or 2, they always burn and only rarely tan. Nearly everyone forgets that a tan is a signal indicating that something has gone wrong in the skin.

To make things worse, some brands advertise sunglasses with lenses that do not absorb the ultraviolet radiation (which is the case for glass that is usually transparent to pigmentogenic UV wavelengths above 315nm), thus allowing one to get a tan in the eye zone. UV exposure can cause irreversible damage to the retina! We do know in fact, that the retina is prone to damage when exposed to radiation between 300nm and 450nm¹; that is, in the UV as well as in the violet-blue region of solar spectrum. We need sunglasses that absorb both UV and visible radiation.

Protecting the Eye

Skiers and glacier hikers know that the eye must be protected to avoid unwanted consequences. At the time when skiing and high-mountain hiking became fashionable (between the two World Wars) goggles and sunglasses were designed in such a way as to hinder radiation from hitting the eye from the front and sides of the face. At that time, though, the physiology of the eye was not known in detail as it is today; people thought UVB (the mutagenic range of ultraviolet) was the only damaging component of solar spectrum.

This misguided thinking led an eminent scientist, Richard Feynman, to wear a clear glass filter to view the White Sands atomic bomb test—all the other scientists watching the test protected their eyes with dark glasses. Feynman wanted to be the only one to witness the full color of the bomb blast and thought that by so doing he would not risk his eyesight. He reasoned that the glass would absorb all the dangerous UV rays emitted from the blast. He mistakenly thought that he had nothing to fear from the remaining intense, but visible, light. The explosion caused him to see a “purple splotch” afterimage.²

But one need not witness an atomic bomb blast to experience high intensity visible radiation; the reflection of sunlight by snow provides a good example of extreme exposure to UV-visible radiation.

Lessons from Greece

Perhaps the first account of the effects of albedo (the reflection of sunlight from snow) on the eye was reported in the logbook of Xenophon, an Athenian officer leading 10,000 Spartan mercenaries from Persia back to Greece. In 401 BC, the mercenaries had fought in the battle of Cunaxa near Babylon, just south of present-day Bagdad. After the battle, the higher-ranking officers of the Greek mercenaries were invited for dinner by the allied Persians and slaughtered; the Persians thought that it would have been easy to enslave the Spartan mercenaries if they were deprived of their commanding officers. But Greek junior officers, among whom was Xenophon, led the mercenaries due North, from Cunaxa to the Black Sea. They embarked on ships and sailed back to the Mediterranean Sea and Sparta.

While crossing a snow-covered mountain in southern Armenia, Xenophon recounts that “Soldiers who lost the use of the eyes, blinded by the snow, or who lost their toes because of the cold, were abandoned.”

For protection against albedo from the snow, “they kept a black fabric before the eyes, and to protect their feet they kept moving continuously.”³

From this we learn that as early as the end of the fifth century BC, Greeks knew the cause-effect relationship between the albedo of the snow and the impairment of the eye, and knew how to avoid it by reducing the number of photons reaching the retina.

Moutaineering maladies

For centuries thereafter, hiking on snow-covered mountains was not a popular activity in Europe. That changed when British aristocrats discovered the thrill of climbing the high mountains that are so cruelly missing in the British Isle. In 1786, Paccard and Balmat reached the top of the Mont Blanc (4,810 meters or 15,780 feet) and in 1808 Marie Paradis was the first female to reach the top. Thirty years later, Henriette D’Angeville summited Mont Blanc and left a detailed account of her expedition.⁴

Upon summiting Mont Blanc, D’Angeville observed her guides suffered various maladies; one’s lips were bleeding and his face was covered with “droplets,” another had a visual impairment, a third had black lips covered with blisters. Curious about her own situation, she took a mirror from her bag and noticed that she had a swollen nose and lips, the white of her eyes was all red and crossed by darker red veins, her face had “grill” marks and was purple from chin to hairline. All of these conditions were caused by albedo.

Final Reflections

The albedo of the snow reflects the quasi totality of solar radiation. This totality makes it even more important to wear protective clothes and sunscreens when skiing or hiking on snow-covered mountains. The tools offered by the market to protect the skin are quite effective and sophisticated. But consumers must be taught to use these tools properly and frequently. The protection of the eye is performed with sunglasses that are not color-neutral in the sense that, by absorbing one wavelength interval more effectively than another, it happens that the colors perceived are distorted. One possibility pointed out by Galas and Eisner¹ is to use melanin in the lenses of sunglasses. Melanin is a color-neutral absorber of UV-visible radiation and can be used advantageously for sun protection of the eye.  

Reference

1. Gallas J & Eisner M (2001) Eye protection from sunlight damage, In: PU Giacomoni (Ed), Sun Protection in Man. Elsevier, Amsterdam, London, New York pages 437-455
2. Feynman RP. (1989) Surely you are joking, Mr. Feynman. In: EH Norton (Ed) Adventures of a Curious Character. Bantom, New York.
3. Xenophon. Anabasis (The Persian Expedition) Penguin Classics
4. H. D’Angeville. (2000) La mia scalata al Monte Bianco. Italian translation by S.Atzeni. Vivalda Editori, Torino.

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Paolo Giacomoni, PhD
Insight Analysis Consulting
paologiac@gmail.com
516-769-6904
 
Paolo Giacomoni acts as an independent consultant to the skin care industry. He served as Executive Director of Research at Estée Lauder and was Head of the Department of Biology with L’Oréal. He has built a record of achievements through research on DNA damage and metabolic impairment induced by UV radiation as well as on the positive effects of vitamins and antioxidants. He has authored more than 100 peer-reviewed publications and has more than 20 patents. He is presently Head of R&D with L.RAPHAEL—The science of beauty—Geneva, Switzerland.