Overexposure to Sun Can Happen Indoors or Out

It's commonly understood that we all need to be careful with how much we sun we expose ourselves to in the outdoors. But did you know that sun overexposure is also a risk when we're indoors, too?

Me either.

New research detailing the transmission of UV light through window glass (such as windows in the home, or windows in the car) as well as through sunglasses means that there are new guidelines and suggestions for preventing sun exposure, both indoors and out.

As you may know, UV radiation from the sun occurs in two forms of ultraviolet light, A and B. UVA is considered to be most responsible for wrinkles and premature aging, while UVB is most likely to cause sunburn. Both UVA and UVB have been linked to the development of skin cancer, of which more than 1 million new cases are diagnosed each year.

Window glass usually filters out UVB rays, but UVA rays can get through. The amount of UVA rays which penetrate the glass depend on the type of glass and type of coating on the glass.

Most residential buildings are made up of one of three kinds of glass: clear, reflective, or tinted. Only reflective glass is effective at minimizing solar heat and UV transmission.

The trend towards constructing buildings with larger windows, combined with the fact that most of us choose to sit near the window while indoors, and the fact that most buildings do not have reflective glass combine to boost our UVA exposure to much higher levels than was previously thought.

The window glass industry has recently developed low-emissivity (low-E) glass. This glass has a special coating between layers of reflective glass, and is capable of reducing solar heat by 70% and UV transmission to as little as 20%.

While indoors, you can protect your skin from the sun by working out of direct sunlight, and using blinds and shades on the windows during peak sun hours.