By Yuval Israel, Year 11
Skin cancer, the abnormal growth of cells in the skin, forms in the lower part of the epidermis, the outer layer of your skin. Cancer takes an estimated 10 million lives every year, and skin cancer alone accounts for a significant portion of these. The main cause of skin cancer is the harmful UV rays emitted by the sun. When exposed to the sun, specialized cells called melanocytes pump a substance called melanin into the surface of the skin, which produces the pigmentation of the skin.
Melanin blocks UV rays from harming the skin, which is why people with naturally lighter skin are more prone to sunburns and why people with naturally darker skin are less prone to sunburns. However, melanin cannot prevent all the UV rays from harming skin cells. When this happens, the rays enter the nucleus of our cells and damage the DNA inside. Damaging the DNA produces Thymine Dimers, which can cause mutations to our DNA. This can in turn cause skin cancer, due to the production of an excess of cells which interfere with the function of healthy cells.
Repairing the DNA after Thymine Dimers are produced is a complex and long procedure by nucleotide excision repair (NER), and the cancer must be recognized instantaneously in order to repair as quickly as possible. Skin cancers such as melanoma is life threatening, as it can spread over your body and even cause death in a matter of 6 weeks.
Sunblock is an easily obtainable, but equally overlooked solution to preventing skin cancer. Sunblock is composed of active ingredients, either physical or chemical. Physical blockers such as zinc oxide or titanium dioxide reflect the UV rays emitted by the sun. Chemical blockers, such as Octocrylene and Tinosorb M, absorb the UV rays. However, they degenerate faster than physical sunblock, as their ability to absorb UV rays diminishes over time. Many people prefer chemical sunscreens as they tend to be less visible, although physical sunblock is known to be more effective. Some people, however, have no choice but to use physical sunscreen due to allergic reactions to the chemicals used in the sunblock.
Whilst it is possible to go a day without sunblock, it is generally not recommended. Although our cells have machinery which can handle the mutations caused by the rays, excessive exposure to these rays is too much for our protective cells to cope with, causing harm to our skin and our DNA and even weakening of our cells’ immune function.
Although it is difficult to find a definitive solution to prevent skin cancer, given factors such as genetic diversity, applying sunblock daily is a scientifically supported way to help protect your skin against cancer, prevent premature aging and skin conditions, and to improve your skin’s health. So, as we approach the sunny spring season, make sure to remember our favorite sunlight suspension: sunblock!
