The Effects of Sun Exposure

Article By: Meghan Cook 12/02/2018

The Effects of Sun Exposure

Work is back for another year and we’ve hit the last month of summer. Most Aussies have been spending a lot of time outside - at the beach, at the park and by the pool. Unfortunately, a lot of Aussies will also reap the consequences of too much time in the sun. We live in a sunburnt country, and it’s not just the tourists flocking to Bondi to blame.

Understanding UV Light

A lot of ultraviolet (UV) light is filtered out by the ozone layer, but some UVA and UVB light does make it through. While you do need some UV light to stay healthy and help produce Vitamin D, it’s very easy to get the amount of need, particularly in Australia where the levels of UV are particularly high.

UV radiation is bad for us because it damages our DNA. Think of your DNA as shaped like a long zipper, where each side of the zipper codes for genetic information your body needs to function. Your cells carry it around zipped up when they don’t need it, so it’s protected and can be condensed down to take up less space. When your cells do need the information, they unravel the intricate coils and unzip a portion to get to the information they need. Exposure to UV can result in damage and cause a lesion in the DNA, kind of like if two teeth on one side of the zipper fused to each other. Fused teeth on one side means they are then unable to interlock with the teeth on the other side, or properly engage with components that run up and down the zipper. Lesions like this need to be repaired or the body can’t read this portion of the DNA properly, which could mean it’s missing out on crucial information.  UV can also bend proteins and other molecules within the cell out of shape, which can then react with DNA and cause further harm.

What are the Consequences of Overexposure?

This can be particularly problematic if a cell containing damaged DNA succeeds in reproducing. During cellular reproduction, cells swell up in size, replicating all the information and components they contain to make sure that the new cell is an exact copy of the old cell. However, mistakes can be made – especially with the intricate process of duplicating all the genetic information held in its DNA. There are a number of checkpoints the cell needs to pass through in order to continue and successfully divide into two. Kind of like a biological auditing process, the cell has fail-safes to repair DNA and correct any “typos” in the information. If the cell didn’t do this, any small mistakes it made would carry over to the daughter cell and potentially impact the way it functions. This is so serious that if there’s too much damage found the cell will kill itself in order not to pass on bad information to future generations of cells. However, much like the important email you’ve proof read a dozen times, just to hit send and realised who spelled your boss’ name wrong – mistakes can slip through the cracks. This is why your risk of cancer increases with age. Most mutations are harmless on their own, but given enough time, their accumulation can align to become the perfect conditions for things to get out of hand.

Understanding Skin Cancer & Getting Checked

Cancer comes about when the mutations in the DNA interfere with the genes that code for the auditing process. If the cell progressively loses information that codes for the checkpoints, cells can start to grow uncontrollably and invade the surrounding tissue. As more generations of badly copied cells are born, the cells take on unfavourable characteristics, diverting precious resources away from crucial bodily functions and spreading to more distant parts of the body. The cells just want to survive and replicate, it’s what they’ve evolved to do, but they’ve lost the information they need to prevent from harming you in the process.

It's an odds game. The more sun you’re in, the higher the chances are that UV damage will eventually hit those crucial areas of your DNA that keep everything in check, particularly over a lifetime of exposure. Trying to minimise your exposure and getting regular skin checks are the best tools at your disposal to stay safe.

SMG Health offer skin check screenings delivered by a medical doctor, on-site for the convenience of your staff members. A simple screening can help identify potential skin cancers before they cause harm, so be sure to book in your regular skin check screening.

For UV forecasts that are updated daily, see the Bureau of Meteorology Website: http://www.bom.gov.au/uv/

For more information on skin cancer, and how to stay safe, please visit the Cancer Council: http://www.cancer.org.au/

 


 

References

[1] Mae R. Gailani, David J. Leffell, AnneMarie Ziegler, Earl G. Gross, Douglas E. Brash, Allen E. Bale; Relationship Between Sunlight Exposure and a Key Genetic Alteration in Basal Cell Carcinoma, JNCI: Journal of the National Cancer Institute, Volume 88, Issue 6, 20 March 1996, Pages 349–354 

[2] http://europepmc.org/abstract/med/11897551

[3] https://www.ncbi.nlm.nih.gov/pubmed/12661961

[4] http://www.who.int/uv/publications/solaradgbd/en/

[5] http://aip.scitation.org/doi/abs/10.1063/1.4897158?journalCode=jcp

[6] https://academic-oup-com.simsrad.net.ocs.mq.edu.au/jnci/article/88/6/349/1004920

[7] http://pubs.rsc.org.simsrad.net.ocs.mq.edu.au/en/content/articlehtml/2002/pp/b201230h

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