For six billion years, the sun has been emitting ultra-violet radiation in two forms that have been identified by the U.S. National Institutes of Health and the World Health Organization as carcinogens. Both the UVA (long) and UVB (shorter) forms can cause the genetic mutations in DNA that cumulatively lead to basal and squamous cell lesions and perhaps even melanoma. Compared to today's average Londoner, Shakespeare was less at risk because of his shorter life span and the filtering protection of the ozone.
UVB radiation is the main cause of skin tanning and burning. While the division is not totally clear, UVA seems to be the main culprit in the aging effects of sunlight, such as wrinkling, sagging and thickening.
It is also responsible for the photosensitivity reactions associated with certain medications (including some naturopathics) and diseases such as lupus and cold sores. Both forms play a role in skin cancer, but unlike UVB, UVA penetrates glass and clouds and puts us at risk all year round.
The good news is that exposure, and hence risk, can be limited. While the most effective remedy is to avoid exposure altogether, wearing a bee-keepers regalia (indoors as well as out) is not an appealing option.
Clothing that blocks or at least filters the rays is certainly worth considering, as is limiting outdoor exposure, especially during sunny days. Indeed this may be the best option for the very young.
For those of us who insist on gardening or playing tennis outdoors, choosing a good sunscreen is important.
Relying on the SPF for a product can be deceiving because it indicates only how much longer it protects against burning than no sunscreen, and it ignores the other serious effects of UV radiation.
There is no satisfactory gauge for judging UVA protection, so the most sensible approach is to ensure that the product you use offers broad-spectrum coverage of both UVA and UVB.
Apart from lotions that are more waterproof or cosmetically acceptable, a good combination of ingredients is the key. An SPF of at least 15 does indicate acceptable UVB protection. And to absorb and block UVA radiation, look for ingredients such as ecamsule (Mexoryl) and avobenzone. Octocrylene or titanium or zinc oxide block both UVA and UVB.
How a sunscreen is applied is a critical determinant of how well it works. It must be applied liberally, and the rule of thumb is one ounce(two tablespoonfuls--externally, of course) for the full body. It should be applied every two hours(unless the label states otherwise) or after swimming or heavy sweating.
It is important to note that a higher SPF rating does not offer significantly higher protection against burning for the time it is effective, but only slightly higher protection for a longer time. Avoid products that combine sunscreen with insect repellant, and if using both, apply the sunscreen first.
So, since Shakespeare's time, the ruddy complexion or "native hue of resolution" whose absence Hamlet bemoaned, has in our time become a source of concern that is at least easier to handle.
BUD MASSENDER, Cates Pharmacy
