May 26, 2023, 13:20 PM by Dr. Sally Robinson

Humans can’t live without the sun which is the closest star to Earth.  It radiates light, heat and solar energy which makes it possible for life on Earth.  However, exposure to Ultra Violet Radiation (UVR) from the sun is the main environmental cause of skin cancer.  Skin cancer is the most common cancer in the United States.  Skin cancer rates have continued to rise since the mid-20th century due to a decrease in the filter of the stratospheric ozone, changes in fashion favoring more exposure, more opportunities for outdoor recreation and exposure to artificial UVR in salons.

Sunlight includes UV-A, UV-B, and UV-C.  UV-A and UV-B have the most significance to humans. This radiation exposure while causing burn damage also causes DNA damage.  If this damage is not repaired by the correct genes, skin cancer can happen.

Sunburning at young ages predicts future skin cancer risk.  The UVR damage adds up and early-life exposure increases skin cancer later.  Most people feel that sunscreen is their main protection but health professionals are encouraging a broader approach.  For centuries clothing has provided sun protection.  For best protection the clothing should be long sleeved, long pants or skirts made of a dark colored tightly woven fabric.  Some clothing has UV protection factor rated by the amount of protection given.  Hats can provide protection and side brims (3 in) provide the most protection.  Sunglasses should be of a product that absorbs 99-100% of the full UV spectrum. 

Midday sun is stronger than early morning and evening sun increasing sunburn risk.  The UV Index found in weather reports predicts the sun radiation intensity for the next day. The higher the number then higher the intensity.  Shade and clouds provide relief from heat but sunburn can still happen as the light beams scatter and are reflected. 

Sunscreen products contain certain chemicals that are effective at certain UV wavelengths.  Usually there are several chemicals for greater protection.  In 2021 the FDA said only two ingredients, zinc oxide and titanium, were Generally Safe and Effective.  There was not enough data to support other ingredients the same.  The American Academy of Pediatrics has expressed concern about the absorption of one ingredient found in some mixtures, oxybenzone, which has hormonal properties and could affect fetuses, breastfed infants and children.  Oxybenzone and octinoxate are banned in Hawaii because of potential harm to sea life.

Broad-spectrum protection (protection from UV-B burning) of at least 15 can have a label that it protects from sunburn and skin cancer when used with other protection measures.  Advice for sunscreen is as follows: an adult needs at least an ounce (2 tablespoons) per application (after 2 hours or swimming); it should not be applied around the mouth and eyes; avoid using sprays, (parents can spray their hands and apply on their children); it is not generally recommended for an infant younger than 6 months and not on areas that can go in an infant’s mouth.

Remember to take recommended Vitamin D (400-600IU) amounts in food and supplement.

by Sally Robinson, MD Clinical Professor
Keeping Kids Healthy
Published 04/28/23

Also See:  

UTMB Pediatrics - Pediatric Primary Care
UTMB After Hours Urgent Care