Sunscreen and Sunburn

The school I go to held a school wide spring fair recently. As part of a Boy Scouts troop, I volunteered to cook and sell hotdogs for 6 hours. But when I got home, I realised I had been severely sunburned and my entire neck was red. This made me regret not putting on sunscreen. But how exactly does sunscreen work?

There are two main kinds of sunscreen, those who's chemicals reflect the sun's rays, and those that absorb the sun's rays. Reflecting ones are called physical sun screens and absorbing ones are called chemical sun screens. Before explaining further, lets talk about why you get a sunburn.

Sunburn is not caused by the heat of the sun or the visible light emitted. Instead, it is caused by ultraviolet radiation that is produced by the fusion happening in the core. This is precisely the reason why you can skill get sunburned on an overcast day. The clouds only block visible light, but the ultraviolet rays can still penetrate through. Once the ultraviolet rays hit your skin, they damage the DNA of your skin cells. This causes the body to react either by repairing the damaged cells, or if they are too damaged to be repaired, they are removed. The body attempting to remove irreparable cells causes the peeling skin associated with sunburn victims. 


Cancer risk: 
Repeated sunburn has been shown to increase the chances of developing certain types of cancer, mainly melanoma, basal-cell carcinoma and squamous-cell carcinoma. As stated previously, the ultraviolet radiation hits the skin and destroys parts of the DNA inside. Normally this damage is repaired or the cell is killed, but sometimes the cell may become cancerous and develop out of control. 




Chemical Sunscreen:
Uses one or more of the following: Oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate. 

Physical Sunscreen:
Physical sunscreen contains zinc oxide or titanium dioxide.

Image Citations: 

N.d. Food and Drug Administration. Web. 27 Apr. 2016. <http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/Tanning/ucm116425.htm>.

N.d. Sammi the Beauty Buff. Web. 27 Apr. 2016. <http://www.sammithebeautybuff.com/2013/08/ingredient-controversy-oxybenzone-plus.html>.