Harmful Effects of Ultraviolet Sunlight, UVA and UVB

Legs on Sandy Beach

With the arrival of Spring and sunnier skies, it is worth a reminder about the power and harmful effects of ultraviolet light.

Sunlight contains both UVA and UVB radiation. These are invisible wavelengths beyond the blue end of the electromagnetic spectrum. UVA, the tanning (and skin wrinkling) portion of the spectrum, is often mistakenly regarded as less harmful than UVB rays.

Effects of Ultraviolet Light

An illustration of the effects of UV light on skin cells.

It is true that UVB packs more energy than UVA. Unprotected skin will burn, sometimes severely, from UVB exposure. However, UVA penetrates deeper into the skin – to a point below the dermis into the subcutaneous tissue. Because the harmful effects of extended UV-A exposure are not as obvious as sunburned skin, they can easily be ignored.

Health professionals now warn that both types of UV radiation can cause skin cancer. For skin protection from both UVA and UVB, use frequent and generous applications of a broad-spectrum, or full-spectrum, sunscreen.

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Dave Burtner

Dave has been active in the lighting industry since 1994. Formerly a member of the Illuminating Engineering Society of North America and certified by the National Council On Qualifications for Lighting Professionals, Dave now writes blog posts, lighting tips and provides lighting product assistance for the Topbulb website.