Hazards in sunlight

What in sunlight is beneficial and harmful to us?

The sun and its light are not only beautiful but vital to our life and survival on this planet. Without the sun, life forms on earth will cease to exist as we know it today. About 75% of our body’s supply of Vitamin D is generated by our skin’s exposure to sunlight (UV-B rays in particular). Abnormally low blood level of Vitamin D increases the risk of colon and breast cancers and may also speed up .the growth of an existing or early melanoma. Of course, Vitamin D can be taken by mouth. The harmful effects of sunlight comes from its ultraviolet (UV) radiation. which could be dangerous to our health in more ways than one, depending on the amount of exposure and dose that a person gets.

What are the sun-related diseases of the eye?

Cataracts (cloudiness of the lens), which, in severe forms, could cause blindness, especially exposure to UV-B radiation; macular degeneration, the major cause of impaired vision in the USA for people older than 55; photokeratitis, a reversible sunburn of the cornea, also from excessive exposure to UV-B; pterygium, growth of pinkish tissues on the while of the eye, which may spread on the clear cornea and block vision. This results when one has prolonged sun exposure on the beach or snow without eye protection, and can be very painful for 1-2 days, with temporary blindness.

How about adverse affects on the skin?

Excessive exposure to UV rays predisposes to skin cancer, which includes the face and the eyelids, besides skin in other parts of the body. There are three major types of cancers of the skin: Basal Cell Carcinoma, the most common one, Squamous Cell Carcinoma, second most common, and Malignant Melanoma, the most deadly, but fortunately, the rarest. Malignant Melanoma spreads easily and often deadly if not caught early.

How prevalent are skin cancers?

This is an epidemic and is a global phenomenon. In 1978, in the United States alone, there were 480,000 cases of non-melanoma skin cancers, rising to over one million in 1994, with a growth rate of 7% per year. In Canada, from 1970-1986, melanoma frequency rose 6% per year for men and 4.6% per year for women. Australia has the highest incidence of melanoma in the world. It is said that by age 75, two out of three Australians will have been treated for some typed of skin cancer. In the United States, the estimated 30,000 cancer deaths each year could be prevented if Americans, who love sunbathing, do not over-expose themselves to the sun.

Are babies and children also affected?

Sun and UV radiation exposure and the use of sunscreen have the same effects on babies and children. It looks funny when we see parents put sunshades (sunglasses) on their babies and children, but there is nothing funny about this practice. Babies and children are not immune to the risk of ocular injury from UV rays. The use of UV protective sunshades and brimmed hat or cap is recommended by Pediatricians, not only to minimize glare and squinting, but to protect the eyes from UV radiation. Sunshades for children must be made of plastic and not glass for added impact protection. There are available baby and children sunscreen skin lotions, but check with your Pediatrician before using them.

Are UV rays in tanning salons safe?

No, the radiation from the UV lamps in tanning salons are extremely harmful. The tan one gets from artificial tanning does not even have the protective effect of sun-induced tan, and, like exposure to the sun, this could cause skin diseases mentioned above. Luckily for our Asian women, they are not that fond of suntan, unlike American and European women.

How do we protect ourselves from UV radiation?

Just like anything in life, moderation is the key. While Americans laugh at Asian women when the latter stay under the shade or umbrella on the beach, they also recognize that Asian women’s complexion looks more youthful, with less wrinkles, and that Asian women look younger in general, compared to Caucasian females. Asian women also have lower incidence of sun-related diseases.

Since UV radiation comes not only from the sun but is reflected from the ground, snow, sand, water, and other reflective surfaces, the use of wide-brimmed hat or cap will reduce the UV radiation to the eyes by 50%. Wrap around UV absorbing eyewear provides the greatest protection, because it also limits radiation from the peripheral rays. Polarized sunglasses or transition lenses reduce glare but do not, by themselves, provide protection from UV radiation.

Sunglasses, and or prescription lenses, that absorb 99-100% of the full UV spectrum to 400 nm are the best for babies, children and adults. Labels on sunglasses should be closely scrutinized to make sure that they say the lenses absorb 99-100% of both the UV-B and UV-A. If they do not have labels, do not buy them. Consumers must be cautious when the label claims the lenses “block harmful UV” but does not specify how much.

For skin cancer protection, do not rely on sunscreen skin lotion. The best is not to sunbathe for more than 20 minutes or so, and if you do, apply “physical” sunscreen lotion. Wear protective clothing and wide-brimmed hat when you go outside during sunny days. Avoid sun exposure between 10 AM and 3 PM if possible. Also, it has been shown that taking vitamin C, D, and E and selenium protects against the damages of UV rays by lessening the adverse effects of the UV rays on the immune system.

If one must absolutely be out in the sun, he/she must wear a “physical” sunscreen with a SPF of 50 or higher, which contains titanium dioxide, zinc oxide or talc. “Physical” sunscreen works by reflecting the UV radiation rather than absorbing the sunscreen into the skin. Doubling the amount of the lotion, or re-applying it later in the day, does not confer added protection.

Lastly, if you develop any skin spots or notice any mole in your body to be growing larger or darker, or feel any lumps in your body, consult your physician without delay. If treated early and caught in time, most skin cancers are curable.

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Philip S. Chua, MD, FACS, FPCS, Cardiac Surgeon Emeritus in Northwest Indiana and chairman of cardiac surgery from 1997 to 2010 at Cebu Doctors University Hospital, where he holds the title of Physician Emeritus in Surgery, is based in Las Vegas, Nevada. He is a Fellow of the American College of Surgeons, the Philippine College of Surgeons, and the Denton A. Cooley Cardiovascular Surgical Society. He is the chairman of the Filipino United Network – USA,  a 501(c)(3) humanitarian foundation in the United States. Email: [email protected]