I’ve recently studied the ozone holes problem and it’s impact on humans health. Here are my conclusions and thoughts:
While increasing the amounts of UV radiation can be beneficial because of general vitamin D increase. [size=75](UV rays help generate vitamin D in humans, and deficiency of vitamin D leads to some cancers… So sunbathing is an important occupation for vegans…) [/size]
UV rays also destroy directly and indirectly the DNA in human body, leading to different skin cancers. It also destroys the vitamin A which is a powerful antioxidant that protects your immune system.
How to protect from too much UV radiation that can lead to skin cancers?
1. Moderation in sun bathing is a good protection. Sunbathing only in the morning till 11:00 and evening after 16:00 is recommended even if you already have good Tan and even if you use Sunscreen.
2. Tan is you protector: The melanin, a substance that gives the color of your tan is generated by your body to protect it from UV-radiation. So starting gradually, very slowly, on moderate sun, to sunbath is a very healthy way to gain more protection from UV-rays. This way you also get the needed vitamin D.
3. Sunscreen prevents the direct DNA damage which causes sunburn. Most of these products contain an SPF rating that describes how efficient the sunburn is suppressed. This protection factor, however, applies only to UVB rays responsible for sunburn and not to UVA rays that penetrate more deeply into the skin and are responsible for malignant melanoma. Some sunscreen lotion now includes compounds such as titanium dioxide which helps protect against UVA rays. Other UVA blocking compounds found in sunscreen include zinc oxide and avobenzone. Cantaloupe extract, rich in the compound superoxide dismutase (SOD), can be bound with gliadin to form glisodin, an orally-effective protectant against UVB radiation. There are also naturally occurring compounds found in rain forest plants that have been known to protect the skin from UV radiation damage, such as the fern Phlebodium aureum. Sunscreen always prevents sunburn, but it protects against free radicals only as long as it stays on the surface. When sunscreen chromophores penetrate into the skin they act as photosensitizers and generate harmful free radicals.
What to look for in sunscreen
(make sure it does not penetrate into the skin!)
* UVB protection: Padimate O, Homosalate, Octisalate (octyl salicylate), Octinoxate (octyl methoxycinnamate)
* UVA protection: Avobenzone
* UVA/UVB protection: titanium dioxide, zinc oxide, Mexoryl (ecamsule)
What to avoid in sunscreen
* octocrylene
* octylmethoxycinnamate
* benzophenone-3
These three substances are proven to increase the amount of free radicals and reactive oxygen species in the skin after they have penetrated into it.
4. A substance called Glutathione protects the cell’s adn - the DNA from the free radicals created by UVA ray. It is synthesized inside the cells from 3 amino-acids: glycine, glutamate and cystine. Due to its high concentration and its central role in maintaining the cell’s redox state, glutathione is one of the most important cellular antioxidants.
Vegan Food Sources That Boost Glutathione Naturally:
Consuming foods rich in sulphur-containing amino acids can help boost glutathione levels.
Milk Thistle, Silymarin
Milk thistle is a powerful antioxidant and supports the liver by preventing the depletion of glutathione. Silymarin is the active compound of milk thistle. It is a natural liver detoxifier and protects the liver from many industrial toxins such as carbon tetrachloride, and more common agents like alcohol. 
Asparagus is a leading source of glutathione. Foods like broccoli, avocado and spinach are also known to boost glutathione levels.
red peppers, garlic, onions, broccoli, brussel sprouts, oats, granola, wheat germ also help to maintain optimal glutathione levels.
Turmeric
Treatment of brain cells called astrocytes, with the Indian curry spice, curcumin (turmeric) has been found to increase expression of the glutathione S-transferase and protect neurons exposed to oxidant stress.