Sunshine and the Human Body


Sunshine is a combination of light and heat from the Sun; it is a portion of the electromagnetic radiation that is emitted by the Sun. It comprises infrared rays, visible light, and ultra violet light. What we see on Earth is not direct sunshine from the Sun; rather, it is sunshine that has already been filtered through parts of the Earth’s atmosphere, such as the ozone layer. Sometimes, the radiation from the sun is also blocked by clouds. Those are not considered sunshine, but are considered diffused light. The term sunshine refers only to the heat and light from the Sun that is not blocked by clouds.

Direct sunlight is very bright. It has a luminous efficacy of about 93 lumens per watt of radiant flux. However, this light and heat also comes along with harmful ultra violet radiation, which contains biologically damaging shortwave ultra violet, which are harmful to human beings.


Benefits of Sunshine

Exposure to sunshine has long been touted as harmful, due to the ability of its harmful ultra-violet rays to cause skin cancer. However, just as health supplements are harmful in massive doses but beneficial in adequate doses, it is prolonged exposure to sunshine and unsafe sun habits that are harmful; sunshine is actually very beneficial for humans in more than one way. For one, sunshine can actually help to reduce a person’s risk of contracting cancer. When one is exposed to sunlight, he gains vitamin D, which has been associated with numerous health benefits. The most significant of these is reduced cancer risk. Studies have also uncovered reduced mortality rates for fifteen to twenty types of cancer (such as breast, colon, and rectal) in regions of the world that have higher ultra-violet exposure. The boosted vitamin D blood levels also aids in calcium absorption in the bloodstream, hence resulting in stronger bones. This in turn causes one to be less likely to develop bone-related illnesses such as osteoporosis and fractures. Another benefit of vitamin D is that high vitamin D blood levels have been correlated to reduced risk of physical problems that one faces when aging, such as cataracts or muscular degeneration. It also contributes to improved blood circulation and reduced blood pressure for persons with hypertension. And as if all these benefits were not enough, vitamin D even boosts one’s immunity! Researchers believe that vitamin D is essential for the body’s T-cells, a white blood cell which plays a crucial role in the immune system, to function properly. Vitamin D also helps to reduce your risk of contracting type two diabetes, which is a lifelong disease that is hard to treat, especially in the case of young children. Studies have shown that children who have adequate vitamin D blood levels have up to 40 percent lower chance of contracting type two diabetes. Hence it can be said that sunshine is a great source of vitamin D for human beings. Why is vitamin D important, though? Vitamin D receptors are present in almost all of the cells within the human body. It has strong effects on the growth and differentiation of many of these cells. In addition, vitamin D is important in for healthy physiology as well, playing an important role in areas such as bone function. However, different people have different absorption rates of vitamin D. For someone who is fair skinned, he or she only needs to spend 10 minutes in the sunshine to produce 10000 IU (International Units) of vitamin D. However, someone with darker skin will have to spend a longer time in the sun to absorb that same amount of vitamin D. Have you been trying to lose weight? Well then, I have good news for you! Another benefit of sunshine on a human being’s health is that it helps to improve one’s metabolism, hence helping the person to fight obesity and lose weight! Studies have shown correlation between exposure to sun and an increase in metabolic rate. Even though correlation does not necessarily imply causation, and there may be other factors in play, but there is indeed a high chance that it is the exposure to sunshine that increases one’s metabolic rate as the warmth from the radiation forces the metabolic processes to work harder. For those with hypertension, sunshine can work wonders for you as well. When one is under the sun, he or she is affected by the heat caused by the radiation in the sunshine. This heat helps to improve blood circulation. In addition, the vitamin D gained from being exposed to sunshine also helps to reduce blood pressure, as mentioned above. Hence, it can be said that sunshine play an important role in maintaining good heart health. One other benefit of sunshine for human health is that it reduces a person’s risk of having a stroke. Although it has not been fully confirmed, surveys have shown that people living in regions with a lower amount of sunshine exposure have up to 60 percent higher risk of having a stroke as compared to those who live in regions with a high amount of sunshine exposure. Sunshine is also important for preventing seasonal affective disorder. Sometimes informally called the “winter blues”, seasonal affective disorder occurs primarily in regions far from the tropics, when there is a lack of sunshine, hence the name winter blues. To treat this disorder, doctors generally prescribe light therapy, using lamps similar to those used in artificial tanning salons to imitate sunlight. With adequate exposure to sunshine, one can have improved mood and lower stress levels, making it less likely to one to contract seasonal affective disorder. Also, when one spends a little time in the sun every day, he or she will have a well regulated circadian rhythm, and hence have a better night’s sleep as compared to those who stay indoors all day long. This results in the person having adequate sleep in rest, in turn causing the person to be more healthy both in terms of physical health, and mental and emotional health. In fact, recent studies have shown that if a person has more exposure to sunshine early in life, he or she could actually face less risk of contracting multiple sclerosis later in life. This is extremely beneficial since multiple sclerosis is an inflammatory disease in which myelin sheaths surround the brain’s and spinal cord’s axons are damaged. This causes failure of the nerve cells to communicate, hence resulting in many physical disabilities. With all these health benefits, it can be said that the benefits of exposure to sunshine far outweigh the risks of developing skin cancer. Besides, one can lower the risk of developing skin cancer due to exposure to sunshine by practising safe sun habits – applying adequate sun block, ensuring that one is not exposed to sunshine for too long, etc. Sunshine not only benefits human beings through giving us boosts to our health. Sunshine can also be harnessed for its solar power. Solar panels, an assembly of photovoltaic cells, can be built to generate and supply electricity in both commercial and residential buildings. Depending on its type, solar panels have different rates at which they convert sunlight to electricity. This rate is called the sunlight conversion rate, also known as solar panel efficiency. The best achieved rate as of yet is around 20.1 percent. Solar energy is an effective and environmentally friendly, not to mention renewable, source of power. Sunshine is in excess in most regions of the world, with a virtually unlimited amount of sunshine to be harnessed every day, so if you do not take into consideration the cost of building and installing the solar panel, it could actually be said that sunshine provides free electricity for us! Not only is sunshine beneficial to humans both in terms of health and being a useful source of energy, sunshine is also beneficial to plants as well! In fact, without sunshine, plants will not be able to survive. Sunshine is essential for plants to carry out photosynthesis, a process through which plants create “food”. In this process, the plants use chlorophyll to convert light energy from sunshine into chemical energy which they then use to fuel their growth and activities.

Disadvantages of Sunshine

Prolonged and excessive expose to sunshine causes one’s risk of skin cancer to increase. Especially as time goes by and the ozone layer decreases, the amount of harmful ultra violet rays that reach the Earth, and reach us, increases. The ozone layer typically obstructs 30 percent of sunshine, hence protecting us from some of the harmful ultra violet rays. As such, a 10 percent decrease in the ozone layer could result in up to 25 percent increased risk of skin cancer. According to the United States of America’s Department of Health and Human Services, ultra violet rays are carcinogens believed to be the cause of an estimated whopping 1.5 million cases of skin cancers in the United States each year. Skin cancer is actually the fastest growing type of cancer, and over half of all new cancer cases are skin cancers. The statistics are rather alarming. According to current trends, one in five children in the United States will grow up to develop skin cancer. The amount of ultra violet rays present differs by location and by season. During the summer, ultra violet radiation can be up to one thousand times higher than in winter. Temperate regions also tend to have higher amounts of the harmful ultra violet rays as compared to non-temperate regions. When we say ‘ultra violet ray’, we actually refer to all three components of ultra violet radiation – ultra violet type A, ultra violet type B, and ultra violet type C, with ultra violet type A being having the highest percentage, making up at least 98 percent of ultra violet radiation at all times. As of now, there really isn’t any concrete evidence on which type is the one that causes skin cancer, or if all of the three types do. At different periods of time throughout the day, different amounts of each type of ultra violet radiation are present in sunshine. Ultra violet type A is most prevalent at around 2pm, with there being around 99 percent of ultra violet type A and only 1 percent of ultra violet type B at that time. For those who are concerned about appearances, you may want to avoid excessive exposure to sunshine, since one other detrimental effect of excessive exposure to ultra violet rays is accelerated skin again, also known as skin photo damage, which is difficult to treat. This condition makes your skin dry, and also causes some other cosmetic changes to your skin, such as dark patches on the skin, known as liver spots. In addition, prolonged and excessive exposure of your optics to sunshine, specifically the harmful ultra violet rays, has been correlated to the formation of cataracts and age related macular degeneration.

A Guide to Safe Sun Habits

With that said, it is important to know how to protect one’s skin from the harmful ultra violet rays when one is planning to spend some time in the sun. If we are to enjoy the full benefits of sunshine, but without putting ourselves at too great of risk of having to experience it detrimental effects, the knowledge and practising of safe sun habits is essential.

  • Avoid going out into the sun during the hottest parts of the day, namely the period from 10 am to 4 pm.
  • Avoid visiting ultra violet tanning salons. They not only increase your risk of developing skin cancer, but will also cause your skin to wrinkly. If you really need to tan, consider using a sun-less self-tanning product instead.
  • Cover up when you are exposed to the sun. For instance, you can wear sunglasses to protect your eyes, or a broad-brimmed hat to protect your face and neck. Try to look for sunglasses that offer ultra violet protection, as sunglasses without ultra violet protection can actually be more harmful to your eyes compared to if you weren’t wearing them, since the dark lenses cause your pupils to dilate, allowing even more of the harmful ultra violet rays to enter the eye. Wearing long sleeved shirts and long pants will also help to reduce the amount of skin exposed to the harmful ultra violet rays.
  • Apply generous amounts of sunblock at least 15 minutes before exposure to sunshine. It is best to use a broad spectrum sunscreen lotion (i.e. one that covers more than one type of ultra violet ray). For example, using a sunscreen that blocks ultra violet type A rays AND ultra violet type B rays would be more useful than one that only blocks ultra violet type A rays. Also, try to use a sunscreen lotion that has high Sun Protection Factor (SPF). Try to choose one that has at least SPF 30.
  • If you are engaging in activities that involve water, such as swimming, or if you expect to be perspiring a lot, choose a water-resistant type of sunscreen lotion. Also, reapply every two hours.
  • Conduct frequent checks of your own skin to look for any signs of skin cancer. We will discuss this further later on in the article.
  • See a doctor every year to have your skin examined professionally.
  • If you have not been in the sunshine for a long time, do not suddenly spend a long time in it. Start by spending a short amount of time in the sunshine, before slowly increasing the amount of time. This will gradually build up melanocytes in your skin, preventing sunburn.
  • Drink plenty of water to stay hydrated, so as to prevent heat injury.

Conducting self-checks – some visible signs you should look out for, especially if you are often exposed to the sunshine for prolonged periods of time: Consult your doctor immediately if you notice multiple moles on your body, or if the moles are atypical, fitting one or more of the descriptions below.

  • Asymmetry: One half of the mole is different from the other half.
  • Border: The mole has a poorly defined border, or if the mole is irregularly shaped and scalloped.
  • Color: The mole varies in color throughout the mole itself. For instance, if one half is brown, and another half is black.
  • Diameter: The mole is larger than 6 millimeters in diameter.
  • Elevation: The mole has an uneven surface, or if the mole is raised above the surface of your skin.

Thank you for reading. May you enjoy the benefits of sunshine safely.


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