THE SUN IS NOT LIGHT BULB

 Everytime we are looking at the sun we see this gigantic white and yellow circle. In those couple of seconds a lot happened, for example the sun release such amount of energy that the whole humanity did not spend in the entire history. Now imagine, heat light, fire, explosion all in one, but wait all of these contain energy. Radiation is energy that comes from a source and travels through space at the speed of light. This energy has an electric field and a magnetic field associated with it, and has wave-like properties. Therefore with all of that energy we have multiple wavelength, giving birth to different variation of radiation. One of these reaches the violet in the spectrum, aka ultraviolet rays, or UV rays. We would like to introduce what this guys are, and how they interact to our body, showing yes the risks that we encounter but the benefits and how to protect ourselves.

It’s sunny, is hot, you are with your friends, the sand is burning under your feet you jump from a shadow to shadow until you dive in the fresh water of the sea. Me and you know that today we do not have responsibilities and we are going to enjoy this relaxing day careless about what is around us. We are young and full of energy we can stand playing beach volley all the day, but who is not standing all the day is our skin. Fortunately our skin is strong and for today it protected us enough, yes we are red like a tomato and we are burning inside, but who cares, right? Next week again new skin, because we peeled off everything, new sunburn. But lets see…I would say that this was not really responsible. So at the end yes we acted careless, but we needed to think about something: OUR SKIN. All that skin that peeled off from the body means that lots of cells died, and if they died it means that something is wrong. The damage was caused by the UV rays.

Between those dead cells there are lots of them which did self-death (apoptosis), this means that they were not anymore good for the body. This because the UV rays penetrate so in depth that hit the DNA, causing a bad change. Many damages can be caused to the DNA by the sunlight but what we are going to focus on is the thymine dimer. Thymidine Dimers are produced when adjacent thymidine residues are covalently linked by exposure to ultraviolet radiation. Covalent linkage may result in the dimer being replicated as a single base, which results in a frameshift mutation. Imagine that our DNA is full of sticks ( nucleotides) next to each other facing to his pair creating a bond. Well that bond is broken by the sunlight and two sticks that are next to each other start fusing creating a sort of bridge, which is detected as a single nucleotide by our organism. The last part is crucial, because this mutation can be repaired by our body only through nucleotide excision repair. This mechanism is not always perfect, and can let mutation to occur. This mutation can give birth to tumoral cells, causing skin cancer.

Unfortunately skin cancers are multiple and differ between them.The skin is made up of 3 main layers:

The epidermis: The outer layer of skin.

The dermis: The inner layer of skin.

The hypodermis: The deep layer of fat.

 

Skin cancer is caused by excessive growth of skin cells that have lost control of their own growth cycle. In most cases, it is due to changes induced by ultraviolet radiation that has accumulated in the skin cells due to excessive or unprotected exposure to the sun or from excessive use of tanning beds.Skin cancer is a common form of cancer; in fact, it accounts for one-third of cancer diagnoses worldwide.There are three main types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and melanoma. In addition, actinic keratosis is a form of precancerous skin growth that can develop into cancer.

It is important to visit a specialist or dermatologist regularly, as it has not been proven that through skin self-examination such cancer can be detected. Nevertheless, it is important to be familiar with the spots or marks on our skin to detect any changes and ensure that a dermatologist observes them closely. The ABCDE rule can be helpful in distinguishing a normal mole from an abnormal formation:

Asymmetry: the two halves of the mole do not match.

Borders that are irregular: the mole has bumpy, irregular, ill-defined or jagged edges.

Color: the most dangerous colors are reddish, whitish and bluish on blackish lesions.

Dimensions: attention should be paid to moles with a diameter greater than 6 mm and/or grown since the last measurement.

Evolution of size, shape, or color: follow and monitor moles and, if changes in size or shape are detected, consult your doctor. 

I know you are reading this now with a scared face, ready to throw away this paper, but wait this does not mean that there are no solutions. We can find different ways to protect us from UV rays, thanks to the sunscreens, which can be physical or chemical. Since going around the beach with an umbrella on your shoulder or in the water is not that comfortable let’s see the physical and chemical sunscreen in cream form. Chemical sunscreen absorbs into the skin and then absorbs UV rays, converts the rays into heat, and releases them from the body. The active ingredients in chemical sunscreens include avobenzone, octinoxate and oxybenzone. Physical sunblock sits on top of the skin and reflects the sun’s rays. The minerals titanium dioxide and zinc oxide are the main active ingredients in physical blocks.

 HOW DO SUNSCREENS WORK?

Sunscreens protect the skin from UV radiation with chemical or mineral filters. Both filters reduce the risk of sunburn, short- and long-term skin damage, and skin cancer. The difference between chemical and mineral protective agents lies in the mode of action.

CHEMICAL FILTERS: The skin absorbs UV rays, which are converted into heat through chemical reactions.

MINERAL FILTERS: create a filter on the surface of the skin that reflects UV rays like a mirror.

MINERAL CREAMS.

Mineral sunscreen is also called a physical sunscreen, as it contains true mineral ingredients (titanium dioxide and/or zinc oxide) that reflect the sun's rays like a mirror and thus protect sun-exposed skin. Therefore, mineral blockers act as a physical barrier on the skin and reflect UV rays from the epidermis of the skin.

✓ ADVANTAGES OF MINERAL FILTER CREAMS:

it protects against UVA and UVB rays,

protection is effective as soon as the cream is applied to the skin,

they do not pollute the sea and the flora and fauna of other waters,

last longer when exposed to direct UV rays, but not during physical activity when the skin gets wet or sweaty,

are suitable for extremely sensitive skin prone to redness and sunburn,

are ideal for acne-prone skin, as they do not clog pores,

are suitable for sensitive skin and children's skin, as they rarely cause skin irritation,

they have a longer shelf life.

✖ DISADVANTAGES OF CREAMS WITH MINERAL FILTERS:

they wash off easily by rubbing or sweating, so they need to be applied more often,

they can leave white spots on the skin,

they provide less protection if they are not applied frequently and evenly in large amounts,

they are more difficult to spread.

CHEMICAL CREAMS.

Sunscreens with chemical filters contain organic carbon-based active compounds (oxybenzone, octinoxate, octisalate and avobenzone) that cause a chemical reaction. The active ingredients absorb the sun's rays, convert them into heat and then radiate the heat through the skin. They are often called chemical or organic absorbers.

✓ ADVANTAGES OF CREAMS WITH CHEMICAL FILTERS:

it is safe protection, since the molecules in the cream do not separate after application,

they should be applied in a thin layer,

they are easy to spread,

they are more comfortable on the skin and under makeup,

skincare ingredients are easily mixed into the formula of sunscreens, so we often find sunscreens with added skincare treatments

✖ DISADVANTAGES OF CREAMS WITH CHEMICAL FILTERS:

can cause and increase skin spotsdue to increased skin temperature (hyperpigmentation),

takes about 20-30 minutes after application to start working,

increased risk of irritation and burns, especially with dry skin,

the higher the SPF, the greater the risk of irritating sensitive skin,

in direct UV light it is absorbed more quickly, so protection is reduced, so it should be applied to the skin more often,

greater likelihood of redness in sensitive people, because it converts UV rays to heat, which can worsen skin conditions,

can clog the pores of the skin,

dangerous to coral ecosystem as it causes coral bleaching (banned in several countries around the world due to environmental threats),

potentially toxic to aquatic ecosystems.

As you can see you have lot of protection if you want. Anyway even if you felt some relief knowing about this sunscreen, do not be hesitant to sun exposure, let me explain. Programs for primary prevention have been launched since it was determined that UV radiation was the primary environmental cause of skin cancer. These programs recommend avoiding sunlight. The issue of whether sun avoidance behavior may have an impact on overall health, however, arises. Throughout the past few decades, more positive connections between sunshine and disease have been found. A increasing body of observational and experimental research shows that frequent sun exposure can prevent diseases like multiple sclerosis, hypertension, diabetes, non-Hodgkin lymphoma, colon, breast, and prostate cancer. Initially, vitamin D was credited for these advantageous benefits. It has recently become clear that other factors, such as immunomodulation, nitric oxide production, melatonin and serotonin levels, and the impact of (sun)light on circadian clocks, are also at play. In Europe (above 50 degrees north latitude), an intermittent pattern of exposure mostly contributes to the risk of skin cancer (especially melanoma), whereas continuous exposure confers a relatively modest risk.

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Kricker A, Armstrong BK, English DR, Heenan PJ. 1995. Does intermittent sun exposure cause basal cell carcinoma? a case-control study in Western Australia. International Journal of Cancer. 60(4):489–494. doi:https://doi.org/10.1002/ijc.2910600411.

Van der Rhee HJ, de Vries E, Coebergh JW. 2016. Regular sun exposure benefits health. Medical Hypotheses. 97:34–37. doi:https://doi.org/10.1016/j.mehy.2016.10.011.

CDC. 2015 Dec 7. What is Radiation? Centers for Disease Control and Prevention. https://www.cdc.gov/nceh/radiation/what_is.html#:~:text=Radiation%20is%20energy%20that%20com

The Best Sunscreen Ingredients: Where They’re Approved — And Banned. 2019 Jun 13. Healthline. https://www.healthline.com/health/beauty-skin-care/best-sunscreen-ingredients#titanium-dioxide.

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Sunburn. https://pixabay.com/images/search/sunscreen/