- UVB rays are the main cause of sunburn and are strongest in the summer.
- UVA rays contribute to premature aging and wrinkles and are constant throughout the year
- UVA rays account for 95% of UV radiation and are 30-50 times more prevalent than UVB rays.
- UVB rays cannot pass through glass, while up to 50% of UVA rays can pass through glass.
Does this mean that protection from the sun by using sunscreen, sunglasses and protective closing is necessary? Again, the answer is yes and no.
The amount of UVA rays that pass through windows depends upon the type of glass as well as on the type of coating on the glass. For example, car windows have been proven to let in more than 60% of UVA rays from the sun. For buildings, recent advancements in window glass have provided a glass that reduces UV transmissions to 20%. Some types of glass can even protect against up to 99% of all UV light but are not common in residential or commercial structures.
Because the type of glass varies from one building and vehicle to another, protection from UVA rays while indoors varies tremendously for one individual to the next. The American Academy of Dermatology says that the amount of time a person spends in the car and/or working near windows can significantly impact the amount of UVA rays he/she receives.
While most Americans spend 80% of their days behind glass, individuals most susceptible to problems caused by UVA rays that make their way through glass include anyone working near windows as well as anyone driving or riding in a car for long periods of time. The more time spent in either situation, the more important to take protective measures.
For those with increased indoor exposure to UVA rays, expert recommendations include the following:
- Always wear a broad-spectrum sunscreen with an SPF of 15 or higher.
- Consider UV eye protection. Many options exist for every unique situation such as the 3M SmartLens Safety Glasses with Photochromic Lenses for those who need safety glasses.
- Use window shades or blinds during times when the sun’s rays are strongest.
- Arrange workspace so as not to always be working close to windows.
- When driving or riding in a car, wear protective clothing (long-sleeve shirt & pants) and wrap-around sunglasses, like the Bobster Defender Sungalsses, that protect against UVA and UVB rays.
- Add tinting to car windows, but make sure the auto facility can meet the federal mandate for tinting.
Many people believe that the type of lighting can also contribute to indoor UV exposure, but research shows lighting sources are not a significant factor in indoor UV exposure. In fact, anti-aging skin care based on independent research indicates that “typical exposure to UV light from commonly used types of fluorescent lamps is relatively small” and “most UV light generated by common halogen lamps is blocked.” However, those same studies to recommend considering extra protection, such as those listed above, for those spending a lot of time under fluorescent or halogen lighting. Research Information provided by The National Electrical Manufacturers Association supports the findings of this independent research.
Bottom line: Even if you’re indoors most of the time, spending a lot of time in the sun coming through windows puts you at risk for UVA-related skin cancer as well as increased wrinkles and premature aging. If this is you, take measures to protect your eyes and skin just as if you were outside in direct sunlight for long periods of time.