UVA vs UVB

I feel like everyone knows about UVB but not many people know about it's horrible big brother UVA. And it's really important you know about both. Not because I'm worried about you burning. You know that you need to be in charge of that. But because I'm worried about much worse damage and I am constantly being talked to about premature ageing. Want skin like a baby? Don't put your face in the sun and wear a high SPF all year round (and don't touch booze, but I'm not a crazy lady).

So I thought I would write a post but first I'd like to say I am not a sun hater. I should wear a hat more than I do, my children are getting browner as the summer goes on and I think Vitamin D is absolutely necessary and we don't get enough of it in the UK. But the free-radical damage starts after 15 mins in the sun and continues for a while after exposure. I don't think you have to baste yourselves in SPF 50+ and huddle inside. But regular broad spectrum suncream application and hats when possible if you are are out for any length of time.

Before I get started just a few things about tanning. Tanning is your skins way of trying to protect further damage to DNA from the sun. It's a reaction in the skin when damage to the DNA starts so by the time you are tanning you are already causing damage. Always wear a 'broad spectrum' sunscream, there are still some available that will only protect you from UVB rays.

UVA 

• This is the one that causes signs of ageing (think of the 'A' as representing 'ageing'). You will not feel it's effect.
• UVA are long wave rays which penetrate deeper into the skin breaking down the collagen and elastin, causing wrinkles. 
• The levels of UVA are pretty much the same all year round in the UK. If there's daylight, there is UVA.
• 95% of Ultra Violet rays that reach the earth are UVA. 
• It's now believed that UVA rays can initiate the development of some skin cancers by indirectly damaging DNA and causing free radicals. 
• UVA penetrates glass - if you drive a lot or sit in front of a window these will be affecting you 
• Can suppress the immune response throughout the entire body and can cause cells in the upper layer of the epidermis to mutate. 

UVB

• This is the one that causes burning (think of the 'B' as representing 'burning'). 
• Short wave rays, UVB mostly affects the top layer of the epidermis which is why any changes are visible reasonably quickly. 
• UVB levels change depending on the time of year. The levels are dependant on cloud cover and other atmospheric factors. 
• Plays a big role in the development of skin cancer as it causes direct DNA damage. 
• Cannot penetrate glass. 
• Can also cause cell mutation and death. 
• More damaging to eyes than UVA.

Both UVA and UVB damage Vitamin A in the skin and damage collagen fibres. A while ago I wrote about why we need to use Antioxidants in your skincare which you might want to read. 

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