The sun always seems to be at maximum sizzle during the dog days of summer when Sirius, the brightest star in the night skies of the northern hemisphere, rises with the sun. Like most of us, I always looked forward to playing outside in the summertime sun as a child, but over time I’ve come to view Earth’s personal star in a fresh light— those seemingly benevolent rays of sunshine are actually a form of solar radiation that deserves a healthy respect.
The dark side of sunlight
The friendly glow of sunlight that stimulates vitamin D production in our skin and makes life possible through photosynthesis also delivers invisible, damaging rays of ultraviolet (UV) radiation that burns the skin, suppresses the immune system, and can cause changes in our DNA. It’s interesting to consider that the highly-prized skin discoloration otherwise known as a sun tan is actually a sign of radiation damage, and I vividly remember treating a patient who’d failed to take adequate precautions against the sun’s rays on his visit from Ireland and suffered horrific results. Incredibly, it’s estimated that about 34,000 people in the US visit the emergency department each year for severe sunburn at a cost of more than $11 million.1 But the problem is more than skin deep: skin cancers that range from less invasive basal and squamous cell carcinomas to more lethal melanomas represent the most common type of cancer in the US, and will affect 1 in 5 individuals over their lifetime.2
Skin deep protection
We know that we should wear sunscreen, sunglasses, and more. And we’re all familiar with SPF, although we tend to forget that this acronym stands for “sun protection factor,” a measure of the time it would take for your skin to start burning if you weren’t wearing any sunscreen at all. In other words, slathering on your favorite SPF 30 sunscreen condenses 30 minutes of UVB ray exposure down to just 1 minute. But the sun can damage skin via UVA rays too, which is why you need to think about using a broad spectrum sunscreen that filters both types of solar ray for best protection. And you may need sunscreen in the office and while driving as well, because although windows typically block the majority of UVB rays, the UVA rays that penetrate more deeply into skin can still shine through with damaging effect.3 It’s worth your while to incorporate a quick application of sunscreen into your daily routine, especially when you know that 65% of melanoma skin cancers and as many as 90% of non-melanoma skin cancers are caused by UV radiation, and nearly 5 million US adults are treated for skin cancer at a staggering $8 billion every year.2,3
It’s important to remember that reflected sunlight from water, sand, and cement may heighten the potential for damage when working and playing outside, and not just to your skin. Unprotected eyes are vulnerable to UV radiation too, which over time may result in cataracts, macular degeneration, and pterygium, a nonmalignant fleshy mass that develops on the mucous membranes of the inner eye and can distort vision. But while cheap sunglasses may come in a variety of attention-grabbing styles they won’t do you any good — you need to look for sunglasses that provide 100% UV protection to block both UVA and UVB rays in a wraparound style designed to shield your peripheral, as well as anterior, eye.4
It may be common knowledge that sunlight — and its invisible UV rays — is strongest during the “mid-day hours,” but it’s actually recommended that you seek shade between 10:00 am and 4:00 pm when solar radiation is most intense.5 It’s also commonly known that UV exposure is greater at high altitudes, close to the equator, and near water, snow, and sand, but did you know that UV radiation can also reach beneath the water’s surface while you’re trying to keep cool and that up to 80% of UV rays can pass through clouds?3 Because the MDGuidelines team cares about what happens to people in the afterglow of too much sunshine, we’ve created a wide range of topics that encompass the effects of direct sun damage (e.g., sunburn, melanoma and non-melanoma skin cancer, cataract, macular degeneration, and pterygium) but also the indirect effects of heat stroke and heat exhaustion. We’re a resource for understanding and for change, and hope that we can celebrate Summer Sun Safety Month this August with the rest of you without any fallout.4
- Guy GP, Berkowitz Z and Watson M. Estimated Cost of Sunburn-Associated Visits to US Hospital Emergency Departments. JAMA Dermatology. 2017. 153 (1): 90-92.
- “Skin Cancer.” American Academy of Dermatology. 1 Aug. 2018. https://www.aad.org/media/stats/conditions/skin-cancer
- “The Burning Facts.” EPA 430-F-06-013. Sep. 2006. Air and Radiation (6205J): United States Environmental Protection Agency. 1 Aug. 2018. https://www.epa.gov/sites/production/files/documents/sunscreen.pdf
- “Summer UV Eye Safety.” American Academy of Ophthalmology. 16 May 2014. AAO. 1 Aug. 2018. https://www.aao.org/eye-health/tips-prevention/summer-sun-eye-safety
- “What Can I Do to Reduce My Risk of Skin Cancer?” Centers for Disease Control and Prevention. 20 Jun. 2018. US Department of Health & Human Services. 1 Aug. 2018. https://www.cdc.gov/cancer/skin/basic_info/prevention.htm