Why Use Window Film?
There’s nothing more important than your health.
Ultraviolet rays (UVR) are sneaky. Not only can they cause skin cancer and visible signs of aging, they’re also very good at finding you. They can bounce off water, off sand, and they can penetrate glass. Which means that even if you’re inside your car or house, if you’re sitting next to a window with sunlight streaming in, you’re at risk for UV damage.
Fortunately, the “window film” revolution is gaining momentum. It began with automobiles in the 1990′s. Research showed that drivers with left-hand drive developed more skin damage on the left side of their bodies, while those with right-hand drive developed more damage on the right.
The reason? UVR streaming through the driver-side windows. “Long-time drivers are found to have rougher, more pigmented skin with greater solar damage on their driver’s side,” noted Albert Kligman, MD, PhD, emeritus professor of dermatology, University of Pennsylvania Medical School, Philadelphia.
All of a car’s windows filter out the sun’s short-wave UVB rays and all glass will filter UVB, but only the windshield in cars comes partially treated against the sun’s UVA rays. However, for several years in all 50 states, transparent UVA-filtering film has been available for vehicles’ side and back window glass. It screens out almost 100 percent of UVB and UVA, without reducing visibility.
And now, UVA-protective film has moved indoors big-time. Residential and commercial films come in flat sheets, in varied tints, cutting down glare by more than half while allowing 30-80 percent of visible light to get through, depending on the customer’s wants. Like automobile film, they block out up to 99.9 percent of UVR. This helps prevent not only sunburn, but also the brief daily UV exposures that cumulatively accelerateskin aging and multiply the risk of skin cancer. In addition, the film can be lifesavers for people with diseases involving dangerous photosensitivity, such as xeroderma pigmentosum and lupus.
- Along with clear health benefits, window film offers other advantages:
- In hot weather, it cuts down heat within the home, which can reduce air conditioning expenses.
- In cold weather, it reflects interior heat back into the house, reducing heating costs.
- It helps keep sunshine from fading car upholstery and home furnishings.
- Some new types of “safety” film help hold residential and commercial glass in place if shattered. Several times thicker than the standard sun-protective film, it can greatly reduce the chances of break-ins, property damage, and even personal injury that can result from broken glass.
Understanding UVA and UVB
For a six billion-year-old star, the sun is certainly in the news a lot lately, mainly because it is still a source of uncertainty and confusion to many of us.
The center of this confusion is the sun’s ultraviolet A (long-wave) and ultraviolet B (shortwave) rays. Our understanding of exactly what kinds of damage each causes to the skin, and how best to protect ourselves, seems to shift every year as new research comes out. For example, it was once thought that only UVB was of concern, but we keep learning more and more about the damage caused by UVA. And new, improved forms of protection against UVA keep emerging. Keeping up with these new developments is a worthwhile challenge that can help all of us prevent sun damage.
What is Ultraviolet Radiation?
UV radiation is part of the electromagnetic (light) spectrum that reaches the earth from the sun. It has wavelengths shorter than visible light, making it invisible to the naked eye. These wavelengths are classified as UVA, UVB, or UVC, with UVA the longest of the three at 320?400 nanometers (nm, or billionths of a meter). UVA is further divided into two wave ranges, UVA I, which measures 340-400 nanometers (nm, or billionths of a meter), and UVA II which extends from 320?400 nanometers. UVB ranges from 290 to 320 nm. With even shorter rays, most UVC is absorbed by the ozone layer and does not reach the earth.
Both UVA and UVB, however, penetrate the atmosphere and play an important role in conditions such as premature skin aging, eye damage (including cataracts), and skin cancers. They also suppress the immune system, reducing your ability to fight off these and other maladies.
UV Radiation and Skin Cancer
By damaging the skin’s cellular DNA, excessive UV radiation produces genetic mutations that can lead to skin cancer. Both the U.S. Department of Health and Human Services and the World Health Organization have identified UV as a proven human carcinogen. UV radiation is considered the main cause of nonmelanoma skin cancers (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). These cancers strike more than a million and more than 250,000 Americans, respectively, each year. Many experts believe that, especially for fair-skinned people, UV radiation also frequently plays a key role in melanoma, the deadliest form of skin cancer, which kills more than 8,000 Americans each year.
Most of us are exposed to large amounts of UVA throughout our lifetime. UVA rays account for up to 95 percent of the UV radiation reaching the Earth’s surface. Although they are less intense than UVB, UVA rays are 30 to 50 times more prevalent. They are present with relatively equal intensity during all daylight hours throughout the year, and can penetrate clouds and glass.
UVA, which penetrates the skin more deeply than UVB, has long been known to play a major part in skin aging and wrinkling (photoaging), but until recently scientists believed it did not cause significant damage in areas of the epidermis (outermost skin layer) where most skin cancers occur. Studies over the past two decades, however, show that UVA damages skin cells called keratinocytes in the basal layer of the epidermis, where most skin cancers occur. (Basal and squamous cells are types of keratinocytes.) UVA contributes to and may even initiate the development of skin cancers.
UVA is the dominant tanning ray, and we now know that tanning, whether outdoors or in a salon, causes cumulative damage over time. A tan results from injury to the skin’s DNA; the skin darkens in an imperfect attempt to prevent further DNA damage. These imperfections, or mutations, can lead to skin cancer.
Tanning booths primarily emit UVA. The high-pressure sunlamps used in tanning salons emit doses of UVA as much as 12 times that of the sun. Not surprisingly, people who use tanning salons are 2.5 times more likely to develop squamous cell carcinoma, and 1.5 times more likely to develop basal cell carcinoma. According to recent research, first exposure to tanning beds in youth increases melanoma risk by 75 percent.
UVB, the chief cause of skin reddening and sunburn, tends to damage the skin’s more superficial epidermal layers. It plays a key role in the development of skin cancer and a contributory role in tanning and photoaging. Its intensity varies by season, location, and time of day. The most significant amount of UVB hits the U.S. between 10 AM and 4 PM from April to October. However, UVB rays can burn and damage your skin year-round, especially at high altitudes and on reflective surfaces such as snow or ice, which bounce back up to 80 percent of the rays so that they hit the skin twice. UVB rays do not significantly penetrate glass.
Protect yourself from UV radiation, both indoors and out. Always seek the shade outdoors, especially between 10 AM and 4 PM. And since UVA penetrates glass, consider adding flat, tinted UV-protective film to your car’s side and rear windows as well as to house and business windows. This film blocks up to 99.9 percent of UV radiation and lets in up to 80 percent of visible light.
Outdoors, dress to limit UV exposure: Special sun-protective clothes with UPF (ultraviolet protection factor) indicate how much UV radiation can penetrate the fabric; the higher the UPF, the better. A shirt with an UPF of 30, for example, means that just 1/30th of the sun’s UV radiation can reach the skin. Laundry additives can also be washed right into regular fabrics to provide higher UPFs. However, you can enhance your sun safety simply by learning to evaluate everyday fabrics’ sun protection qualities and choosing those with the best protection.
For instance, bright- or dark-colored, lustrous clothes reflect more UV radiation than do pastels and bleached cottons; and tightly woven, loose-fitting clothes provide more of a barrier between your skin and the sun. Finally, broad-brimmed hats and UV-blocking sunglasses help shield the sensitive skin on your head, neck, and around the eyes ? areas that usually sustain a lot of sun damage.