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How Does Ultraviolet Radiation Cause Skin Cancer

Signs & Symptoms Of Ear Cancer

How UV Causes Cancer and Aging

The symptoms of ear cancer depend on the location of the tumor. Swelling of cervical lymph nodes can be seen in some patients. The most common symptom of cancer in the middle ear is a discharge from the ear that can be stained with blood. Other symptoms of ear cancer include earache and hearing loss. Some patients are not able to move their face on the side where the ear cancer is. Symptoms of cancer in the inner ear include pain, hearing loss, headache, dizziness and tinnitus.

How To Avoid It

The single best thing you can do for your skin is to never get sunburnt. Getting sunburnt just once every two years can triple your risk of melanoma the most dangerous form of skin cancer.

Using sun lotion with a high SPF, covering up with clothes, staying in the shade and avoiding the midday sun are all sensible things to do. Check out the NHS website for more tips on sun safety.

What Happens When You Get Sunburnt

UV radiation from the sun is always present, whether its a cloudy day or blazing hot outside. Some types of UV radiation can even get to you through windows, which is why its a good idea to wear some form of SPF every day. There are three main types of UV radiation UVA, UVB and UVC. You dont really need to worry about UVC as it is absorbed by the Earths atmosphere. UVA and UVB rays are the ones that cause serious harm by penetrating into the skin and damaging proteins, membranes and the DNA in your skin cells.

UVA rays A as in ageing penetrate deep into the skin where they cause damage to elastic fibres and DNA. They are thought to be responsible for 80% of visible skin ageing.

UVB rays B as in burn hit the top layer of your skin and cause the typical symptoms of sunburn. They damage DNA and kickstart an inflammatory response, leading to swelling, redness, heat and pain in the affected area. This immune response already begins while youre still enjoying the warming rays from the sun and peaks about one or two days later, which is why you sometimes wont realise how badly you got sunburnt until its too late. Some of the cells in your skin will also start producing melanin to protect the skin, resulting in a tan. But any form of tan means that DNA in your skin cells has been damaged, so unfortunately there is no safe amount of tanning.

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What Are The Different Types Of Uv Radiation Rays

UV radiation is classified into three primary types: ultraviolet A , ultraviolet B , and ultraviolet C . These groups are based on the measure of their wavelength, which is measured in nanometers .

Wave Types, Wavelengths, and Absorption Levels

Wave Type
Not absorbed by the ozone layer Mostly absorbed by the ozone layer, but some does reach the Earths surface Completely absorbed by the ozone layer and atmosphere

All of the UVC and most of the UVB radiation is absorbed by the earths ozone layer, so nearly all of the ultraviolet radiation received on Earth is UVA. UVA and UVB radiation can both affect health. Even though UVA radiation is weaker than UVB, it penetrates deeper into the skin and is more constant throughout the year. Since UVC radiation is absorbed by the earths ozone layer, it does not pose as much of a risk.

What Causes Skin Cancer

Does UV radiation cause cancer?

Over 80% of skin cancers are caused by overexposure to UV radiation. This includes UV rays from the sun, but also from sunbeds and tanning lamps. UV radiation damages DNA in your skin cells, which can accumulate over time and increase the risk of genetic mutations that cause skin cancer. The more often you get burnt, the more damage is done and the higher the risk of skin cancer. Its also important to know that you dont necessarily need to get a sunburn for UV rays to damage your cells.

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What Is The Ozone Layer

Ozone is a trace gas that forms the ozone layer within the stratosphere, which is part of the atmosphere around the Earth.

  • There are three molecules of ozone for every 10 million molecules of air.
  • Ozone is a highly reactive molecule that contains three oxygen atoms.
  • Ozone absorbs solar UVR, which heats the atmosphere.
  • Ozone also shields the Earth from the biologically harmful effects of UVR.
  • Reduced ozone leads to higher levels of UVR on the Earths surface.

The Surgeon Generals Call To Action

The is a first step in promoting community awareness to prevent skin cancer. Using an existing health promotion model applied to melanoma prevention, some have suggested that patients need the knowledge, tools, and incentives to change behavior, and that community health awareness is also key. The Surgeon Generals goals to educate the community about UV exposure, the hazards of indoor tanning, and skin cancer prevention, as well as conducting research, are all well within the scope of practice for the oncology nurse.

One nursing organization has taken the lead on promoting the . The Dermatology Nurses Association in their Position Statement recommends educating patients and the community about both primary and secondary prevention. In 2007, Dermatology Nurses Association endorsed the Childrens Melanoma Prevention Foundations SunAWARE acronym as their official prevention standard because it recommends avoiding unprotected exposure to UV radiation, never indoor tanning, proven sun protection practices, and routine skin self-examination.

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What Is The Ultraviolet Index

In response to the increasing incidence of skin cancer, cataracts, and other effects from exposure to the sun’s harmful rays, the National Weather Service , the US Environmental Protection Agency , and the Centers for Disease Control and Prevention collaborated on a sun-awareness information program. An important part of this program is the Ultraviolet Index, developed by the National Meteorological Center of the National Weather Service.

The Index is a next-day forecast that estimates the amount of ultraviolet radiation that will reach the earth’s surfaceproviding important information to help you prevent overexposure to the sun’s rays. The Index also includes the effects of cloud cover on the anticipated UV exposure level for the next day.

The Factors Contributing To Uvr

How Cancer Cells are Formed by UV Rays

The occurrence and development of BCC mainly depend on the interaction between general characteristics, such as genotypic and phenotypic features and subsequent environmental risk factor exposure. Therefore, as a primary risk factor, UVR could be combined with or influenced by other factors, such as general characteristics, UVR sources , and other environmental factors to induce the onset of BCC.

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Why Does Uv Radiation From The Sun Cause Skin Cancer

What is the specific mechanism makes non-ionizing UVA and UVB radiation carcinogenic? Can lower energy light, like visible light, be carcinogenic because of this mechanism, or is there some kind of threshold within spectrum at which electromagnetic radiation does not induce cancer in humans?

Ionizing radiation can be mutagenic, which can cause cancer. However, this only applies to high-energy electromagnetic radiation with photon energies exceeding about 5 eV, or about 248 nm. These photon energies correspond to UVC, which is blocked thoroughly by the atmosphere, meaning Sunlight does not appreciably contribute to the ionizing radiation we receive on Earth. Therefore, the mechanism with which solar UV radiation induces cancer must be different from higher energy electromagnetic radiation, right?

  • 1 Nilay GhoshApr 2 ’21 at 5:46
  • $\begingroup$It’s not an answer which is acceptable on this site, but the best explanation of the electromagnetic spectrum I’ve ever seen is ElectroBoom on YouTube. This is in relation to 5G but explains why radio is safe and why UV-C isn’t: youtube.com/watch?v=i4pxw4tYeCU$\endgroup$

Rather than ‘breaks’ caused by high energy radiation, UV radiation causes chemical modifications of the bases that make up DNA. There are four bases in the DNA alphabet abbreviated to A,T,G or C belonging to two classes. A & G are guanines while T & C are pyrimidines.

The elevated states of compounds are stronger acids and reductants than the ground states.

Cutaneous Responses To Uv

UV has many effects on skin physiology, with some consequences occurring acutely and others in a delayed manner. One of the most obvious acute effects of UV on the skin is the induction of inflammation. UVB induces a cascade of cytokines, vasoactive and neuroactive mediators in the skin that together result in an inflammatory response and causes sunburn . If the dose of UV exceeds a threshold damage response, keratinocytes activate apoptotic pathways and die. Such apoptotic keratinocytes can be identified by their pyknotic nuclei and are known as sunburn cells . UV also leads to an increase in epidermal thickness, termed hyperkeratosis. By causing cell injury, UV induces damage response pathways in keratinocytes. Damage signals such as p53 activation profoundly alter keratinocyte physiology, mediating cell cycle arrest, activating DNA repair and inducing apoptosis if the damage is sufficiently great. Several h after UV exposure, however, and damage response signals abate, epidermal keratinocytes proliferate robustly , mediated by a variety of epidermal growth factors. Increased keratinocyte cell division after UV exposure leads to accumulation of epidermal keratinocytes which increases epidermal thickness. Epidermal hyperplasia protects the skin better against UV penetration .

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What About Tanning Beds

Some people think that getting UV rays from tanning beds is a safe way to get a tan, but this isnt true.

Both IARC and NTP classify the use of UV-emitting tanning devices as carcinogenic to humans.

The US Food and Drug Administration , which refers to all UV lamps used for tanning as sunlamps, requires them to carry a label that states, Attention: This sunlamp product should not be used on persons under the age of 18 years.

The FDA also requires that user instructions and sales materials directed at consumers carry the following statements:

  • Contraindication: This product is contraindicated for use on persons under the age of 18 years.
  • Contraindication: This product must not be used if skin lesions or open wounds are present.
  • Warning: This product should not be used on individuals who have had skin cancer or have a family history of skin cancer.
  • Warning: Persons repeatedly exposed to UV radiation should be regularly evaluated for skin cancer.

The FDA has also proposed a new rule to ban the use of indoor tanning devices by anyone under age 18, to require tanning facilities to inform adult users about the health risks of indoor tanning, and to require a signed risk acknowledgment from all users. Some US states have already banned indoor tanning by all people younger than 18, while others have banned use by younger teens and children.

Uvr And Damaging Effects

Care in the Sun

The epidemiology implicating UV exposure as a cause of melanoma is further supported by biological evidence that damage caused by UVR, particularly damage to DNA, plays a central role in the development of melanoma. The relative risk of skin cancer is three times as high among people born in areas that receive high amounts of UVR from the sun than those who move to those areas in adulthood. Likewise, outdoor workers have a higher risk than indoor workers.

The aforementioned citations conclude that there is a dose-related relationship between sunlight exposure and the incidence of skin cancer. For the development of BCC and melanoma, intermittent intense exposures appear to carry a higher risk than lower level chronic exposures, even if the total UV dose is the same. By contrast, the risk for SCC is strongly associated with chronic UV exposure but not with intermittent exposure. Taken together, epidemiologic studies and experimental studies in laboratory animals indicate that intermittent intense and chronic exposures to solar UVR are the primary cause of NMSCs and melanoma.

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Are There Any Other Health Issues Related To Uv Radiation

In addition to skin cancer, exposure to UV rays can cause other health problems:

  • UV rays, either from the sun or from artificial sources like tanning beds, can cause sunburn.
  • Exposure to UV rays can cause premature aging of the skin and signs of sun damage such as wrinkles, leathery skin, liver spots, actinic keratosis, and solar elastosis.
  • UV rays can also cause eye problems. They can cause the cornea to become inflamed or burned. They can also lead to the formation of cataracts and pterygium , both of which can impair vision.
  • Exposure to UV rays can also weaken the immune system, so that the body has a harder time fending off infections. This can lead to problems such as reactivation of herpes triggered by exposure to the sun or other sources of UV rays. It can also cause vaccines to be less effective.

Some people are more sensitive to the damaging effects of UV radiation. Some medications can also make you more sensitive to UV radiation, making you more likely to get sunburned. And certain medical conditions can be made worse by UV radiation.

How Uv Rays Affect The Skin

UV rays usually react with melanin, a chemical found in the skin. The first line of defence against the sun is this. Melanin absorbs UV rays, which can cause serious skin damage. However, melanin alone cannot absorb all UV rays, and some people have very little melanin in their skin. Ultraviolet Radiation cause Skin Cancer and its exposure has been linked to a variety of health problems, including:

  • Get a sunburn. When the amount of UV rays reaching the skin exceeds the amount of protection that the skins melanin can provide, a sunburn occurs. Sunburn causes skin damage. It causes pain, redness, and blistering.
  • Skin ageing before its time. Photoaging is the term for premature skin ageing. Over time, it causes the skin to thicken and become leathery. Freckles, wrinkling, collagen loss, and the widening of small blood vessels in the skin are all signs of photoaging. People who sit in the sun on a regular basis may experience these changes earlier and more quickly.

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What Are The Signs And Symptoms Of Skin Cancer

The most common warning sign of skin cancer is a change on the skin, typically a new mole, a new skin lesion or a change in an existing mole.

  • Basal cell carcinoma may appear as a small, smooth, pearly, or waxy bump on the face, or neck, or as a flat, pink/red- or brown-colored lesion on the trunk, arms or legs.
  • Squamous cell carcinoma can appear as a firm, red nodule, or as a rough, scaly, flat lesion that may itch, bleed and become crusty. Both basal cell and squamous cell cancers mainly occur on areas of the skin frequently exposed to the sun, but can occur anywhere.
  • Melanoma usually appears as a pigmented patch or bump. It may resemble a normal mole, but usually has a more irregular appearance.

When looking for melanoma, think of the ABCDE rule that tells you the signs to watch for:

  • Asymmetry: The shape of one half doesn’t match the other.
  • Border: Edges are ragged or blurred.
  • Color: Uneven shades of brown, black, tan, red, white or blue.
  • Diameter: A significant change in size .
  • Evolution: Changes in the way a mole or lesion looks or feels .

Ultraviolet Radiation And Sun Exposure

How UV Rays Damage Skin
  • Too much ultraviolet radiation from sunlight is dangerous.
  • Nearly half of UV radiation is received between 10 a.m. and 4 p.m., when the suns rays are the strongest.
  • Even on a cloudy day, you can be sunburned by UV radiation.

Weve all heard the phrase, a healthy tan, but there is no such thing. Tanning is your body’s attempt to protect itself from being damaged by ultraviolet radiation.

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What Are The Risks From Uvr Exposure

Overexposure to UVR can cause sunburn, skin damage and skin cancer. UVR exposure also places our eyes at risk of photokeratitis, photoconjunctivitus and cataracts. The most obvious short-term effect of overexposure to UVR is sunburn, also known as erythema. The more UVR exposure, the worse the sunburn becomes. A person’s cumulative exposure to UVR along with the number of severe sunburns they have received, especially during childhood, increases their risk of developing skin cancer. Skin cancers affect people of all skin types.

Melanoma, the least common of the skin cancers but the most dangerous, is related to severe exposure to solar UVR at an early age. In Australia, 96.1% of all melanoma cases in 2012 were attributable to UV radiation. This accounts for 11 400 cases and 9.54% of all cancers. This is the worlds second highest percentage, just behind New Zealand.

Malignant melanomas may appear without warning as a dark mole or other dark spot on the skin. Any concerns regarding moles or skin spots should be referred to a doctor or skin clinic. Further information about skin cancers can be obtained from the Cancer Councils.

Prolonged exposure to solar UVR can have serious consequences for the eyes. Cataract is one of the most common types of eye damage in Australia. Cataract is the clouding of the lens of the eye, which is responsible for focusing light and producing sharp images. Without intervention cataract can lead to blindness.

How To Use Sunscreens

A sunscreen protects from sunburn and minimizes suntan by absorbing or reflecting UV rays. Using sunscreens correctly is important in protecting the skin. Consider the following recommendations:

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