Understanding and using sunscreen is essential to successfully minimizing risk of sun-induced skin cancer. The best approach to avoid damaging exposure is in using a high-factor sunscreen, stay out of mid-day sun, and have regular planned periods of time in the shade. Many sunscreen users are ignorant of the real level of protection they are receiving from their product. Research has shown that most people are getting only one third of the protection they think they are getting.
People seldom apply sunscreen at the levels used by the researchers that establish the sun protection factor (SPF) values. Manufacturers typically test their products at a ratio of 2mg/sq. cm. of skin to determine SPF ratings. People typically apply 0.5 to 1.5 mg/sq. cm. In order to get a more realistic estimate of protection, the labeled SPF value should be divided by three.
If you apply sunscreen like most people and rub it in rather than let it sit on top of the skin, your protection is approximately one third of the intended SPF value. Fact is, people tend not to apply any more sunscreen than they are comfortable using. If you normally use SPF 15, you should use SPF 45 to get the protection you think you’re getting.
As we age, our DNA is less likely to repair and replace cells damaged by the sun’s UV energy. To get a tan you need to damage your skin, and fair complexions damage more readily. Approximately one third of Americans have pre-malignant marks on their skin and most of these are elderly.
Discuss with your doctor the risks associated with sun exposure, the efficacy of sunscreen and your personal risk of malignant melanoma. Prevention is the best approach to avoiding this potentially lethal and often environmentally caused disease.