|Take steps to protect yourself from UVR damage
(Photo credit: Kathleen Kvilhaug)
Thursday, September 25, 2014 10:00 am
Let’s get technical for a moment:
Ultraviolet radiation (UVR) is a form of energy produced by our sun. UVR is the invisible part of the light spectrum that reaches the earth. There are three types of ultraviolet rays or wavelengths contained in sunlight: UVA, UVB, and UVC. UVR is measured in nanometers (or nm) and falls within the range of 100-400 nm on the electromagnetic spectrum.
UVC, being the shortest of these three wavelengths (100-280 nm), can be very damaging. The good news is UVC is mostly absorbed by the atmosphere and ozone layer before it can reach earth. A very good reason to be concerned about protecting our ozone layer!
It is the longer wavelengths of UVA and UVB that pass through the earth’s atmosphere where they exert their harmful effects on our health. Approximately 95% of UVR reaching us here on earth is UVA. However, it is UVB, the other 5% that is actually more intense and damaging.
UVA, the longest of the ultraviolet rays (315-400 nm), penetrates the dermis layer of the skin where it causes tanning, skin thinning, and aging. Recently, UVA was further sub-divided into UVA2 (315-340 nm) and UVA1 (340-400 nm). This sub-division was due to the discovery of the cross over damage potential of this spectrum.
UVB, the medium wavelength (280-315 nm), penetrates the epidermis and the top layers of the dermis. UVB is responsible for causing redness, sunburn and direct damage to the DNA of the skin, changes that lead to skin cancer development.
Ok, got that? Good…now here’s the important take-away:
Spending time in the sun’s ultraviolet rays increases your risk of skin cancer (basal cell carcinoma, squamous cell carcinoma and malignant melanoma) and early skin aging. Additionally, UVR exposure can also cause short and long-term effects on the eyes, including the development of cataracts and ocular melanoma.
Given the unpleasant risks associated with excessive ultraviolet exposure, it makes good sense for you to take steps to protect yourself from these potentially serious health consequences.
Next: A look at the new recommendations in sun-protection measures