Gamma rays are the most harmful external hazard. Beta particles can partially penetrate skin, causing “beta burns”. Alpha particles cannot penetrate intact skin. Gamma and x-rays can pass through a person damaging cells in their path.

Gamma radiation is the most penetrating. It can penetrate air, paper or thin metal. It may only be stopped by many centimetres of lead or many metres of concrete.

Alpha particles

There are three main kinds of ionising radiation:

• alpha particles, which include two protons and two neutrons.
• beta particles, which are essentially electrons.
• gamma rays and x-rays, which are pure energy (photons).

Gamma radiation

Gamma rays

There are three types of nuclear radiation: alpha, beta and gamma. Alpha is the least penetrating, while gamma is the most penetrating.

The radioactive decay products we will discuss here are alpha, beta, and gamma, ordered by their ability to penetrate matter. Alpha denotes the largest particle, and it penetrates the least. Alpha particles carry a positive charge, beta particles carry a negative charge, and gamma rays are neutral.

Inside the body, however, they can be very harmful. If alpha-emitters are inhaled, swallowed, or get into the body through a cut, the alpha particles can damage sensitive living tissue. The way these large, heavy particles cause damage makes them more dangerous than other types of radiation.

The measurement is exceedingly difficult since cosmic rays can outnumber gamma-rays at these energies by a factor of 10,000 to 1 or more!

gamma-ray burst

They are produced by the hottest and most energetic objects in the universe, such as neutron stars and pulsars, supernova explosions, and regions around black holes. On Earth, gamma waves are generated by nuclear explosions, lightning, and the less dramatic activity of radioactive decay.

Just as high doses of X-rays are typically lethal, so too would an explosion of gamma rays kill the average person. Still, gamma rays can have medical applications — a medical device known as the gamma knife can kill tumors by aiming gamma rays at a patient’s brain.

With the gamma-rays beamed directly at Earth, the radiation would destroy a significant portion of our atmosphere, specifically the ozone layer. The photons streaming from the burst would cause chemical reactions leading to photochemical smog. This would further deplete our protection from cosmic rays.

Becquerel

To cause death within hours of exposure to radiation, the dose needs to be very high, 10Gy or higher, while 4-5Gy will kill within 60 days, and less than 1.5-2Gy will not be lethal in the short term. However all doses, no matter how small, carry a finite risk of cancer and other diseases.

Physicists do not think the sun emits any gamma rays from within. (Nuclear fusions in its core do produce them, but they scatter and downgrade to lower-energy light before leaving the sun.) And the signal becomes up to 20 times stronger than predicted for gamma rays with the highest frequencies.

Gamma rays are widely used in medicine and specifically in the area of oncology to treat malignant and cancerous tumors during a process called gamma knife surgery. In this type of treatment, concentrated beams of gamma rays are directed at tumors in order to kill cancerous cells.

Since radiation therapy is focused on one area of your body, you may experience fewer side effects than with chemotherapy. However, it may still affect healthy cells in your body. Side effects of radiation may include: digestive issues like nausea, vomiting, stomach cramps, diarrhea.

The human eye can’t see gamma rays, although at some point, the gamma rays may damage the eye enough so that you’d be able to know that something is happening. Human eye can only see things between ultra violet and infra red. That’s why they are called such things.

Another distinctive factor of radiation is whether it is ionizing, or non-ionizing radiation. Non-ionizing is potentially less harmful than the latter because radiation of this type has less energy than ionizing and can cause molecules to move in an atom but it cannot remove electrons.