Window Distance from Indoor UVA

[jack sprat]

Dr. Todorov notes that indoor UVA intensity decreases with the distance you keep from the windows. How far back one should be remains a question to me.

A US News and World Report article from June 27 of 2008 spoke with Henry Lim, chairman of the department of dermatology at Henry Ford Hospital in Detroit. The reporter talked to Lim specifically about UVA exposure at the office. "Since UVA rays pass through glass, you might need to protect yourself if you're situated right by a window with strong sun exposure. However, Lim says that sunscreen isn't necessary if your desk is more than a few feet from a sunny window."

Does this seem like a realistic standard? A few feet of distance is not so hard to arrange generally at home or in the office, but I would think UVA would travel further along with the visible light, rather than fade out that quickly once passing through glass.

[drtodorov]

Generally, as far as skin aging is concerned, if it preferable not to be in direct sunlight, even if it is coming thru a [regular glass] window. For indirect sunlight, the indoor UVA exposure would depend on many factors, such as size of windows, distance from windows, variations of window glass, time of day, and so forth.