Among the many reasons to get out into the wilderness and head on a mountaineering or trekking expedition is to be outside and enjoy some sunshine.
While scrolling through those bright and sunny mountain panorama photos on your social media platform of choice may have you yearning for the next outdoor adventure, it is important to remember to bring adequate sun protection.
Sun-protective clothing, sunglasses, sun cream and lip balm will all help to protect your eyes and skin from irritation, burns and damage caused by ultraviolet (UV) radiation.
What is UV radiation?
Ultraviolet radiation is a form of energy invisible to the human eye. UV light is located between the visible light spectrum and X-rays on the electromagnetic spectrum.
Three types of UV radiation – UVA, UVB and UVC – are emitted naturally by the sun. However, only UVA and some UVB radiation penetrate the Earth's atmosphere.
Along with passing through the atmosphere, UVA and UVB radiation penetrate the outer layer of the skin, arriving at much deeper layers where connective tissues and blood vessels are affected.
The pros and cons of UV radiation exposure
While some UV radiation can benefit the immune system by stimulating the production of vitamin D and helping blood circulate more freely, too much UV radiation exposure has plenty of adverse side effects.
In the upper skin cells, UVA radiation activates already-present melanin, which results in a brief tan. Conversely, UVB radiation stimulates the production of new melanin, too much of which can result in sunburns.
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Recent research strongly suggests that prolonged exposure to UVA and UVB radiation may enhance the development of skin cancer.
While the mechanisms are still poorly understood, one leading hypothesis is that UV radiation increases oxidative stress in the cells and impairs their ability to repair damaged DNA.
Along with damaging the skin, too much exposure to ultraviolet radiation also damages the cornea and lens of the eyes, with excessive damage resulting in eye diseases such as cataracts and conjunctivitis.
Why does mountaineering or trekking put you at higher risk of UV radiation?
Keeping all of this in mind, it is also important to understand why mountaineering and trekking present additional UV radiation risks to most normal activities.
Six main factors affect the amount of radiation to which you may be exposed:
- Time of day
- Time of year
- Weather conditions
Regarding mountaineering and trekking, altitude, reflection and time of year are the most important factors defining risk.
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Higher altitudes have greater UV exposure because the atmosphere is thinner and absorbs fewer UV rays. According to the United States National Institute of Health, UV levels increase about 4 per cent with every 1,000 foot (300 metre) increase in elevation.
Reflection is another important factor in mountaineering as nearly all UVA and UVB radiation can be reflected from snow-covered, ice-covered and glaciated surfaces.
The late spring, summer and early autumn are when many mountaineering and trekking expeditions take place in both hemispheres, but they also coincide with when the sun is strongest, and the amount of UV radiation arriving is highest.
How to protect yourself from UV radiation while trekking or mountaineering
Trekkers and mountaineers can do three things to protect themselves from the harmful effects of UV radiation: wear sun-protective clothing, use UV-protective sunglasses and regularly apply sun cream and lip balm.
Wearing the proper clothing is the easiest and simplest way to protect yourself from UV radiation while on a trekking or mountaineering expedition. Clothing creates a physical layer that will block most of the UV radiation coming your way.
In recent years, many popular outdoor clothing brands have also started manufacturing clothes with dyes or chemicals that absorb UV radiation, adding further protection to shirts, hoodies, pants, neck buffs and sun hats.
These clothes will come with a UPF – ultraviolet protection factor – which is measured similarly to how SPF – sun protection factor – is for sun creams.
According to the Skin Cancer Foundation, “excellent” outdoor clothing has a UPF of 40 to 50, which indicates that the fabric will allow one-fortieth or one-fiftieth of the UV radiation to pass through the material to your skin.
Overall, the foundation indicates a minimum UPF of 30 is required for adequate sun protection outdoors. For comparison, a classic white cotton t-shirt offers a UPF between 5 and 8.
Marmot, Columbia, L.L. Bean, Exofficio, Patagonia, Royan Robbins and Mountain Hardware are some outdoor clothing brands that sell high UPF clothing.
While high UPF clothing will be a bit more expensive than non-UPF counterparts, it is possible to treat everyday clothing items at home by washing them with a laundry additive, such as Sun Guard.
Protecting your eyes from UV radiation should be paramount on any trekking or mountaineering expedition.
Due to the nature of the two activities, which will involve hours of steady and continuous movement, it is important to find a pair of sunglasses that are comfortable on your face and offer adequate protection for the conditions.
According to the American Academy of Ophthalmology, sunglasses for trekking and mountaineering should block 99 to 100 percent of UV radiation and therefore recommend UV 400-protected sunglasses. UV 400 protection indicates that the lenses block wavelengths up to 400 nanometers in length.
While UV 400 sunglasses are the gold standard for UV protection, this measurement alone does not indicate how well the glasses will block glare – intense light that reflects off shiny surfaces, such as snow or water.
When traversing a glacier or climbing to a snow-covered summit, having a clear vision is just as important as UV protection.
Therefore, mountaineers and trekkers should ensure their UV 400 sunglasses are ISO category 3 or 4. These are the darkest sunglasses on the market and will absorb between 82 and 98 percent of visible light, virtually eliminating glare.
Along with their UV and visible light specs, it is important to find a pair of mountaineering sunglasses that are comfortable to wear for hours at a time while moving, sweating and going in and out of shaded areas.
As a result, mountaineering enthusiasts recommend wraparound sunglasses, which feature a curved shape to fit the shape of your face and head. The sunglasses should also come with removable side shields, offer plenty of ventilation and be compatible with different types of helmets.
Julbo, Monterosa, Oakley and Chums are some of the most highly-rated mountaineering and trekking sunglasses brands.
Sun cream and lip balm
Once you have selected the sun-protective clothing and UV 400-protective sunglasses of your choosing, it is time to think about sun cream.
Healthcare professionals recommend that trekkers and mountaineers bring broad-spectrum sun cream with a minimum of SPF 30 on any outdoor adventure.
SPF 30 sun cream protects users from 97 percent of UVB rays for up to two hours, after which point this protection quickly fades, and more sun cream will need to be reapplied. Mountaineers and trekkers also should apply sun cream 15 minutes before heading out into the sun for the day.
In addition to protecting users from the more harmful UVB rays, broad-spectrum sun cream also protects users from the more prevalent UVA rays, prolonged exposure to which can also have negative consequences on skin health.
Beyond the level of protection from the sun, it is important to find sun creams that are water and sweat-resistant. Most sun creams will explicitly state this on the label, so keep an eye peeled for it when shopping around.
For the environmentally-conscious trekker or mountaineer, it is also important to check the ingredients of sun cream before buying.
Zinc oxide is a popular ingredient that is more expensive than others on the market but offers effective protection, especially in harsh environments, and is organic, so it pollutes less.
Sun creams with oxybenzone and octinoxate have been linked to coral reef damage and have even been banned in some places. Eco-friendly outdoor adventurers should avoid sun creams with these ingredients.
Among the most popular sun cream brands for trekkers and mountaineers are Baby Bum, Badger, Blue Lizzard, Neutrogena and Thinksport.
Along with sun cream, bringing and using lip balm is essential for all the same reasons. The lips are an often neglected part of the body in terms of sun protection but burn just as quickly as the face or neck.
Among the most popular brands for mountaineers are Aquaphor, Dermatone, Dr. Dan’s, eos, Jack Black, Lip Collagen, O’Keefe’s, Palmer’s, Power-Full and Sun Bum.
Heading on a mountaineering or trekking expedition is never a bad idea, and ExpedReview offers plenty of diverse options for participants of every ability level and proclivity.
However, before heading out on the trail, it is essential to know the risks of sun exposure and how to protect yourself from UV radiation best.