Red. Hot. Painful. Itchy.
I was not so clever this weekend, and forgot to reapply sunscreen while hanging out in the pool.
And now I’m suffering the consequences.
The thing is, I’m sure I’m not alone.
The Cancer Council estimates that over two million of us Aussies will get sunburnt over an average summer weekend.
That’s a lot of people experiencing the pain of a good sunburn.
The physical signs of sunburn – the red, hot skin, and associated pain – are a result of the damage caused by UV light.
UV light, a type of radiation, has enough energy that it can pass through our cells, and reach the DNA hidden inside.
When it does, it damages it, causing changes in the structure of DNA.
To put it more simply, UV radiation causes mutations.
Fortunately, given that we‘re constantly exposed to low levels of UV light, our cells have mechanisms to repair this damage.
So if we’re just exposed to a little bit of UV, and have a little bit of DNA damage, our cells can take care of this.
The problems begin when we get exposed to a LOT of UV light – like when I was out in the sun for hours on the weekend.
Lots of UV exposure means lots of DNA damage – too much for our cells to simply repair. If cells with this much DNA damage were allowed to survive, there is a good chance that they would lead to us having cancer. So instead, our body directs these cells to die.
As our damaged skin cells die, our immune system is activated, and it sends in specialised cells to clean up the mess left by all of these dying cells.
As this immune response takes place our bodies also increase blood supply to the area.
Combined, these things leave us with skin that feels hot, red, and sore.
Luckily, we can quickly grow new skin cells to replace all the ones that have died.
And the old, dead ones? Well, in a couple of days they peel off – leaving your sunburnt areas looking like something out of a horror movie.
Even though we have this pretty great system to either repair DNA damage, or to destroy cells with too much damage, it isn’t perfect.
Sometimes cells manage to survive, even with DNA damage, and can become cancerous.
So don’t be like me. Remember to slip, slop, slap this summer.
Dr Mary McMillan is a lecturer at the University of New England’s School of Science & Technology.
