ALL THINGS UV RAYS!
Let's talk skin and UV rays today! Our sun emits 3 main types of UV rays: UVC, UVA, and UVB.
- Highest energy out of all the UV rays
- Shortest wavelength
- Doesn't make it past the ozone layer
Even though UVC rays contain the highest energy, thankfully, due to its strong reactivity with the ozone layer and short wavelengths, it usually doesn't make it past the ozone layer. This means that our skin is generally not affected by UVC rays. However, there are a few man-made sources that due produce UVC rays such as mercury lamps and UV sanitizing lamps. For the most part, UVC doesn't affect our daily lives and it is not something we need to be concerned about.
- Lowest energy out of the UV rays
- Longest wavelength
- Rays are known to cause skin cells to age
- Damage to skin's DNA indirectly
- Long term skin damage such as wrinkles
- May play a role in some skin cancers
- 95% of UV rays that reach our skin are UVA rays
- Penetrates through glass such as windows
- Penetrate deeper into our skin than UVB rays
- Cannot "feel" UVA rays
- Present year round
UVA Rays are the most common UV rays that your skin will come into contact with. Due to its long wavelength, it penetrates deep into your skin and into the dermis layer (middle layer). These rays are known to be the "silent killer" because you can't "feel" the rays when they are doing harm to your skin. These rays have long term, harmful effects on your skin and steadily destroy key substances that are responsible for your skin's firmness and elasticity. Long term exposure also causes wrinkles and can even alter your skin's DNA, potentially raising your chances of developing skin cancer. It's also important to note that most tanning beds/booths emit UVA rays since these are the rays that give your skin a tan.
- Medium energy out of the UV rays
- Causes skin to burn
- Causes skin discoloration
- May also cause skin cancer
- Time, weather, geographic location, and season affect the intensity of UVB rays
- Reflects off of snow (80%!!), sand, and water
- More damaging at higher altitudes
- Damage DNA skin cells directly
- Helps skin produce vitamin D3
UVB Rays are the rays that typically give you a sunburn and cause a quick change in skin color after being out in the sun. UVB rays only reach the epidermis (outer) layer of your skin. UVB rays are also present year round, however, the time, weather, geographic location, and season can affect the intensity of the UVB rays while this is not really the case with UVA rays. In the Northern Hemisphere, UVB rays are strongest from April to November and during daylight hours between 11am to 4pm. The one positive thing UVB rays do provide is that it helps your skin produce vitamin D. However, more research needs to be done to see how much vitamin D you actually need and it's also hard to tell how much vitamin D you are getting from sun exposure. It's advised to get your vitamin D through your diet and/or supplements.
Protect your skin
You can easily avoid/protect your skin from UV rays by wearing a broad-spectrum sunscreen with at least an SPF of 30! Make sure it says broad-spectrum because this provides protection from BOTH UVA and UVB rays. It also helps if you limit/avoid sun exposure when its strongest (11am to 4pm if you're in the Northen Hemisphere). You can also wear hats, UV protected sunglasses, long sleeves, etc. however this does not fully protect you from UVA since it can penetrate through clothes too. Standing in the shade might help a little bit, however, UV rays reflect off the ground and through clouds so it can still penetrate your skin even though you aren't directly exposed to sunlight. To be safe, it's best to wear broad-spectrum sunscreen all over!