RadiationAlex and Daniel DeRose

Period: 11

Chemistry Project

What is Radiation? Radiation is the emission of energy as electromagnetic waves

or as moving subatomic particles, especially high-energy particles that cause ionization.

Radiation has a wide range of energy that forms the electromagnetic spectrum. The spectrum has two major divisions: ionizing and non-ionizing radiation.

Ionizing Radiation Ionization is the process in which a charged portion of a molecule (usually an

electron) is given enough energy to break away from the atom.

Ionizing radiation is so high in energy it can break chemical bonds. When these bonds are broken, it can charge (or ionize) an atom that interacts with it.

When at a lower energy, it may break off a couple of electrons. At a higher energy, it can destroy the nucleus of an atom. This means that when ionizing radiation passes through the tissues of the body, it actually has enough energy to damage DNA.

Examples: electromagnetic radiation, particulate radiation, medical x-rays, nuclear radiation (from nuclear explosions, weapons, etc.), industrial gamma rays, and consumer products (such as TVs or certain lights).

Nuclear explosions contain many sources of ionizing radiation. When nuclear explosions occur, the radiation (gamma rays, x-rays etc.) superheat the air and causes it to combust.

There are three main kinds of ionizing 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).

Non-Ionizing Radiation Non-ionizing radiation is low-energy radiation that doesn't have

enough energy to ionize atoms or molecules.

We are exposed to non-ionizing radiation everyday.

It is located at the low end of the electromagnetic spectrum.

Examples: power lines, microwaves through telecommunication and heating food, radio waves from broadcasting, infrared radiation from lamps, ultraviolet radiation, visible radiation, cell phones, and lasers.

Some forms of non-ionizing radiation can damage tissues if you are exposed too much to it (such as sitting in the sun for too long, and getting sunburn).

Overexposure to non-ionizing radiation can cause health issues, such as damaged skin, burns, cancer, cataracts on the eye, etc.

How Radiation is Measured The exposure to radiation is represented by the following equation:

Exposure = Dosage x Q

The amount of radiation absorbed over time. It is measured in Rads, Grays (the SI unit) (1 Gray = 1

rad), or ergs (1 Rad = 100 ergs).

The amount of tissue damage caused by

radiation This varies between different types of radiation: For x-rays and gamma rays, Q=1.

For alpha particles, Q = 15-20

(depending on amount of particles) For neutron rays,

Q=10.

Compares the radiation exposure to the amount of

tissue damage (Q). It is measured in rems. It could be measured in seiverts

(Sv), but it is mostly measured in rems. 1 SV =

100 rems

Radiation Exposure on the Human Body Ionizing radiation, particularly nuclear radiation, can produce fatal

consequences if the human body is exposed to large amounts of radiation. Something is “irradiated” when radiation is exposed to it, and could potentially be damaged by it.

Ionizing radiation may act on cellular parts or simply just water inside human cells. Radiation can react with water, creating water derived radicals, which if it reacts with nearby molecules like cell parts, it will result in the breaking of chemical bonds of these molecules through oxidation.

The most major effect of radiation in cells is the breaking of DNA molecules. As mentioned above, radiation may break the double-stranded DNA, and if the cell tries to repair that DNA, it will often “disrepair” itself and create errors in new DNA. This results in cell death.

Radiation exposure to the body most often occurs in chemotherapy in cancer patients, so radiation exposure is small and only kills targeted cells. But in situations like nuclear accidents, radiation can kill cells all over the body.

All radiation exposed to the body increases a person’s risk for cancer. Although most radiation we are exposed to is non-ionizing, small tasks like talking on your cell phone for long periods of time for a long time can caused pain in the ear because of the radiation that modern cell phones emit.

Radiation Exposure on the Human Body (Continued)

Sample Problem During the test run of an atomic bomb in the United States, the overall

dosage of radiation given off by the bomb was estimated to be 14.1 seiverts. The bomb produced mainly neutron rays to be emitted. What was the overall radiation exposure that people would have experienced if the bomb was really used in a populated area? Would people survive?

1. Convert seiverts to rems 14.1 seiverts x = 1410 rems

2. Q = 10, since neutron rays produce about 10 units of tissue damage3. Exposure = 1410 rems x 10.

4. Exposure = 14,100 rads.

14,100 rads causes instant death, so people wouldn’t be able to survive.