Wound Cream

Radiation Burn

A radiation burn is damage to the skin or other biological tissue caused by exposure to ionizing radiation.

The most common type of radiation burn is a sunburn caused by UV radiation. High exposure to X-rays during diagnostic medical imaging or radiotherapy can also result in radiation burns. As the ionizing radiation interacts with cells within the body—damaging them—the body responds to this damage, typically resulting in erythema—that is, redness around the damaged area. Radiation burns are often associated with cancer due to the ability of ionizing radiation to interact and damage DNA, occasionally inducing a cell to become cancerous.

Cavity magnetrons can be improperly used to create surface and internal burning. Depending on the photon energy, gamma radiation can cause very deep gamma burns, with 60Co internal burns are common. Beta burns tend to be shallow as beta particles are not able to penetrate deep into the person; these burns can be similar to sunburn.

Ionizing Radiation

Ionizing radiation has many practical uses, but it is also dangerous to human health. Both aspects are discussed below.

Ionizing radiation is either particle radiation or electromagnetic radiation in which an individual particle/photon carries enough energy to ionize an atom or molecule by completely removing an electron from its orbit. If the individual particles do not carry this amount of energy, it is impossible for even a large flood of particles to cause ionization. These ionizations, if enough occur, can be very destructive to living tissue, and can cause DNA damage and mutations.

Examples of particle radiation that are ionizing may be energetic electrons, neutrons, atomic ions or photons. Electromagnetic radiation can cause ionization if the energy per photon, or frequency, is high enough, and thus the wavelength is short enough. The amount of energy required varies between molecules being ionized. X-rays, and gamma rays will ionize almost any molecule or atom; Far ultraviolet, near ultraviolet and visible light are ionizing to some molecules; microwaves and radio waves are non-ionizing radiation.

Types of Ionized Radiation

Ionizing radiation is produced by radioactive decay, nuclear fission and nuclear fusion, by extremely hot objects (the hot sun, e.g., produces ultraviolet), and by particle accelerators that may produce, e.g., fast electrons or protons or bremsstrahlung or synchrotron radiation.

Sunburn

A sunburn is a burn to living tissue such as skin or leaves produced by overexposure to ultraviolet (UV) radiation, commonly from the sun's rays. A similar burn can be produced by overexposure to other sources of UV such as from tanning lamps, or occupationally, such as from welding arcs. Exposure of the skin to lesser amounts of UV will often produce a suntan. Usual mild symptoms in humans and animals are red or reddish skin that is hot to the touch, a washed out feeling, and mild dizziness.

Sunburn can be life-threatening and is a leading cause of cancer. Sunburn can easily be prevented through the use of sunscreen, clothing (and hats), and by limiting solar exposure, especially during the middle of the day. The only cure for skin burn is slow healing, although skin creams can help.

In the winter time, windburn is commonly confused with a sunburn, with typically milder symptoms.

Development and Consequences of Sunburn

Typically there is initial redness (erythema), followed by varying degrees of pain, both proportional in severity to the duration and intensity of exposure. The condition occurs when incident UV radiation exceeds the protective capacity of melanin in the skin. Concentrations of this pigment vary greatly among individuals, but in general, darker-skinned people have more melanin than those with lighter skin. Correspondingly, the incidence of sunburn among dark-skinned individuals is lower.

UV radiation is divided into the UVA (380–315 nm), UVB (315–280 nm) and UVC (280-180 nm) sub-bands. Ozone in the Earth's atmosphere filters out a portion of this before it reaches the planet's surface. UVC is almost entirely eliminated by the atmosphere, but enough UVA and UVB penetrates it in large enough quantities that sunburn can occur in less than 15 minutes. Nevertheless, the inflicted harm is often not immediately obvious.

After the exposure, skin may turn red in 2 to 6 hours. Pain is usually most extreme 6 to 48 hours after exposure. The burn continues to develop for 24 to 72 hours occasionally followed by peeling skin in 3 to 8 days. Some peeling and itching may continue for several weeks.

Common symptoms of sunburn include tenderness, pain, edema, itching, red and/or peeling skin, rash, nausea and fever. Also, a small amount of heat is given off from the burn, giving a warm feeling to the affected area. Sunburns may be first- or second-degree burns.

Protection Against Sunburns

Skin

It is advisable to consult a UV index to determine what level of protection is necessary. Potential forms of protection include wearing long-sleeved garments and wide-brimmed hats, and using an umbrella when in the sun. Minimization of sun exposure between the hours of 10 a.m. to 3 p.m. is also recommended.

Commercial preparations are available that block UV light, known as sunscreens. Sometimes called suncreams or sunblocks, they have a Sun Protection Factor (SPF) rating, based on the sunblock's ability to reduce the UVB radiation at the skin: the higher the SPF rating, the greater the protection. A sunscreen rated SPF15 blocks 93.3% UVB and an SPF30 rated sunscreen blocks 96.7%. It is best to use a broad spectrum sunscreen in order to protect against both UVA and UVB radiation. It is prudent to use waterproof formulations if one plans to engage in water-based activities. The best sunscreens attenuate UVA radiation as well UVB. Note that the stated protection factors are only correct if 2 µl of sunscreen is applied per square cm of exposed skin. This translates into about 28 ml (1 oz) to cover the whole body of an adult male, which is much more than many people use in practice.

Eyes

Eyes should not be neglected, and wrap-around sunglasses which block UV light should also be worn. UV light has been implicated in pterygium and cataract development.