UV rays are a part of the electromagnetic spectrum and radiant energy and the wavelengths are measured in nanometers. The spectrum ranges from ultraviolet to the far-infrared.
The Ultraviolet rays come from the sun directly and are divided into three different wavelengths. Such as:
- UVA Wavelength: These wavelengths range from 320 to 400 nanometers. They are only affected by the ozone layer by a small amount and able to reach the earth which is why people are able to tan, get eye damage, get skin aging, and immune suppression.
- UVB Wavelength: This wavelength ranges from 280 to 320 nanometers and is highly affected by the ozone layer. In the stratospheric ozone layer, it is decreased which means that more UVB wavelengths reach the earth and can cause sunburns, snow blindness, immune suppression, and different skin cancers.
- UVC Wavelength: Is ranged from 100 to 280 nanometers and is also mainly affected by the ozone layer. The rays that hit the earth’s surface is a small amount and doesn’t cause much damage.
Scientists aren’t very sure of what the UV radiation does the earth’s ecosystems. Any UV radiation causes major damage to small animals, plants, fish eggs, phytoplankton, and young plants.
During the middle of the day is when the UV radiation levels are the highest. Clouds also can have an effect on UV levels. However, when clouds are present they do not protect us from the UV rays.
Positive Effects
There are many positive aspects to UV and it isn’t the opportunity to sell sunscreen. UV rays produce vitamin D to the body, which helps to make our bones strong and keeps us safe against diseases such as Rickets. It is also good therapy for psoriasis, which is a skin condition where the skin sheds off the skin to fast and results in patches on the skin that is itchy and irritated.
Ultraviolet rays are also good for disinfecting the fish tanks and for sterilizing the medical equipment. A lot of animals use UV rays for their own uses. An example would be how bees use the reflection from the rays in order to help them collect pollen.
Negative Effects
Although UV rays can serve a purpose, it is important to note that the exposure from the rays can be harmful, deadly, and can lead to different health issues.
Skin
Sunburn or erythema is one of the main effects of Ultraviolet exposure. Sunburn happens when the skin cells are damaged by having too much exposure and absorption to the UV rays. In order for the skin to heal, it sends more blood to the damaged area which is why the sunburn is seen as red. A sunburn heals depending on the number of UV rays that hits the skin and on that person’s skin type. It is known that people who have dark skin have high levels of melanin and takes a longer time to receive a sunburn.
Photoaging is another effect from UV rays. It has been proven that aging such as wrinkles and loose skin is caused by exposure to UV rays.
UV Index
The UV index was created in order to help inform the public about Ultraviolet waves. The UV index is the same all over the globe.
- 1-3: Low exposure
- 4-6: Medium
- 7-9: High
- 10+: Extreme exposure
The amount of time you can spend out side also depends on your skin type. An example would be if you had light skin and the index was seven, then it would take 20 minutes or less for you to start turning red.
Skin Cancer
A lot of people assume that if you can’t see the rays then it can’t hurt you but this is not true. One of the effects of these rays is that you can get skin cancer. The American Cancer Society had assumed that there would be more than 51,400 cases of melanoma in 2001. There has been an increased rate of skin cancer since the 1970s. The increase in melanoma cases means that cancer is a real issue in America.
Basal and Squamous Cell Carcinoma
There are three main types of cancer and they are melanoma, basal cell carcinoma, and squamous cell carcinoma. The most common and dangerous forms of non-melanoma cancers are basal and squamous cell carcinoma. It’s highly believed that UV-B rays are the main cause of these cancers. A good note to make is that cancer happens when damaged cells start to divide and invade other parts of the body and kill the healthy tissues and cells. For skin cancer, UV rays are the main cause. The p53 gene is the specific cell that takes effect in the basal and squamous cancers. Usually, the gene is supposed to fight against cancer by damaging the cancerous cells. But, if the cell is unrepairable then the p53 gene activates for the cell to kill itself.
Malignant Melanoma
There are not many causes of malignant melanoma. Many scientists theorized that UV-A radiation is the main cause of melanoma. This means that a lot of sunscreens have a small amount of protection and they only protect you against UV-B rays. Sunblock blocks the UV-B rays and this allows fair-skinned individuals to be outside for a longer amount of time. Although sunscreen is helpful, it doesn’t protect you again UV-A rays which is what causes you to tan and allows even more UV-A rays to enter the skin. So, if you want to block UV-A rays it would benefit you to wear a hat and the appropriate clothing.
How to Identify Melanoma?
A good way to know if you have a growth mole is by remembering the ABC’s:
- A: Asymmetry. Does the mole look the same on both sides?
- B: Border Irregularity. Are there smooth edges or crooked edges?
- C: Color. Is there an uneven color?
- D: Diameter. Is the mole larger than 1 cm?
If a mole develops later on, then you should be concerned. There are many moles that appear when you are a child and can become malignant. It’s important that you keep an eye out for any change in the appearance.
Australian Skin Cancer
Australians get skin cancer more than anyone else. More than 1200 Australians are diagnosed and die from skin cancer every year. This is because Australia is more exposed to the ultraviolet radiation levels because the levels are higher.
During the summer because of Earth’s orbit, Australia is significantly closer to the sun and this results in an increased solar UV intensity. This means that Australians are exposed 15% more to the UV rays than anyone else.
The Cancer Council Victoria had created a cartoon that was first launched in 1980. The character of the show was a seagull named SunSmart and he was to fight against skin cancer and mortality rates.
Ever since the show was aired, people had different attitudes towards tanning and sun protection. The Australians all had realized what precautions they needed to take when going outside for long periods of time. Now, skin cancer deaths have slowed down majorly and many people are detecting cancer early which is improving their survival rate.
Effects on Eyes
Sand and snow are some substances that can reflect UV rays into the eyes. The UV rays are increased when exposed into the eyes. This is learned from photokeratitis, which is also known as snow blindness. Photokeratitis is when the cornea is sunburned and recedes in one to two days. This happens when the eyes or overexposed to the ultraviolet lights.
It’s hard to know the exact damage that UV rays can cause to the eyes over a long period of time. When you look directly at the sun, you would notice that your eyes would start to close. Getting too much UV rays in the eyes can cause cataracts, this is a condition that is normally found in elderly people and can end in blurry or fuzzy vision.
Effects on the Environment
There are many species that benefit from the UV rays, but the rays also have a negative effect if the ray levels continue to increase.
Effects on Phytoplankton
UV rays can cause trouble for phytoplankton which are organisms that live in the ocean. This is an issue because phytoplankton is the first source of the food chain for fish. An increase in the variations of the population can cause an imbalance in other marine life such as fish and whales. Scientists are inspecting the Antarctic waters because of the increase of UV-B exposure to the phytoplankton.
Effects on Plants
The production rate of crops can decrease if there is an overexposure to UV-B rays. Many people across the world are trying to make crops resistant against the ultraviolet rays. There are a few species of plants that are sensitive to UV radiation and there other others like rice that have strong resistance. With this information, scientists are able to find more species of plants that are able to withstand ultraviolet resistance for food supply.