To the Editor.—
In regard to an essay that appeared in a letter to the Archives (111:1538, 1975), I question the statement that window glass offers protection from ultraviolet rays. To substantiate this, I refer to a report by Willis and co-workers (J Invest Dermatol 59:416-420, 1972), in which they state that contrary to previously accepted hypotheses, long ultraviolet rays have a striking augmentative effect on sunburn damage. Long ultraviolet rays are not filtered out by window glass.Also, Demis1 reported that a 20-minute photopatch test through window glass that was performed during June (noon at 42° latitude) showed a positive reaction after 60 minutes.
Forbes MA. Protection of Skin From Sun. Arch Dermatol. 1976;112(11):1615. doi:10.1001/archderm.1976.01630350081029