我也是 UVA exist even rain weather

来源: 2010-05-21 14:29:11 [旧帖] [给我悄悄话] 本文已被阅读:
The sun has 2 types of UV, (ultraviolet), rays:

1. UVA

2. UVB

UVA:

Long-wave solar rays of 320-400 nanometers, (billionths of a meter). You're almost never safe from exposure to UVA rays as they can go through windows, light clothing and even your windshield, so if you're outside you're getting exposed to UVA rays.

UVA rays are responsible for aging. They are less likely than UVB to cause sunburn but UVA penetrates the skin more deeply, causing wrinkling and leathering of the skin.

Prolonged exposure of UVA cracks and shrinks the collagen and elastin of our skin.