Radiation Curriculum
Table of Contents
I.
Overview
A. What is Radiation?
B. Types of Radiation
C. Chart of Wavelength
D. X-Rays vs. Gamma Rays
E. Units of Measurement for Radiation
F. Earth’s Orbit and its Effects on Exposure to Radiation
G. Biological Effects of Radiation
II.
Sources of Exposure to Radiation
A. Background/Naturally Occurring
B. Medical Process
C. Abnormal/Man Made
D. Prevention
III. Uses/Effects
A. Beneficial Applications of Radiation (Health, Industry,
Etc.)
B. Hazards of Radiation Exposure
IV. Model Systems for Studying the Effects of Radiation
V.
Statistics Related to Radiation’s Health Effects on Humans
Grade Level: Middle School (6th-8th); High School (9th-12th)
Georgia Standards: S6E2, S6E6, S7L2, S7L4, S8P4; SCSh9, SP4, SMI5, SEV4, SAP5, SC2, SC3, SAST1,
SAST3
Science Earth Science Standard; Science Life Science Standard; Science Physics Standard;
Science Characteristics of Science high School Standard; Science MIcrobiology Science Standard;
Science EnVironmental Science Standard; Science Human Anatomy and Phsyiology Science Standard;
Science Chemistry Science Standard; Science ASTronomy Science Standard
Purpose of activity: Educate students about radiation exposure and links to cancer and provide them
with the knowledge to make informed decisions that will reduce their risk of exposure.
Goals/Objectives:
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


I.
understand how the Earth's tilt and orbit contribute to energy transfer
understand how cell structure is degraded from abnormal and natural radiation exposure
understand the patterns and characteristic of waves to their contribution toward energy
addresses how various elements and energies affect our environment and health through
different mechanisms which target key organic structures
Overview
A. What is Radiation?
i. Radiation is the term for energy that travels through space, including air,
water, the ground, and outer space. Radiation travels in a path that looks
like a series of waves. Depending on the shape of the waves and the rate at
which the waves are formed, radiation can have different properties.
Examples of radiation include the light we use to see, heat from the sun
and the signals created and received by cell phones. One way in which
types of radiation differ is in their wavelength. One wavelength is defined
as the distance between the peaks of two adjacent waves. The complete
range of frequencies and energies that characterize different forms of
radiation is called the electromagnetic spectrum. It is comprised of radio
waves, microwaves, infrared light, visible light, ultraviolet light, x-rays,
and gamma rays. The speed, frequency, and energy of each wave type are
used to sort radiation into different categories. (1)
B. Types of Radiation
i. Radiation can be split into two categories, non-ionizing radiation and
ionizing radiation. (2)
1. Non-ionizing radiation
a. This type of radiation is common in everyday life and we
are regularly exposed to it. Normal amounts of this type of
radiation are experienced as lower frequency radiation such
as radio waves, infrared, visible, and ultraviolet light.
However, extreme amounts of these non-ionizing radiations
can lead to damage in human tissue.
i. Radio frequency (RF) – Longest wavelength;
typically used for communication, radio or radar
signals
ii. Microwaves (MW) – Has a slightly shorter
wavelength than radiofrequency; used for radar,
radio transmission, and cooking
iii. Infrared (IR) – Falls just between microwaves and
visible light on the spectrum; used for heat detection
or remote controlled objects.
iv. Visible light – This is a small band of color that
human eyes are able to see; this type of radiation is
expressed to us as colors, red, orange, yellow, green,
blue, and violet.
v. Ultraviolet Radiation (UV) – This form of radiation
comes from the sun as well as other stars, and ravels
to earth though our ozone as high energy. This type
of radiation helps to heat the earth.
2. Ionizing Radiation
a. There are two types of radiation categorized as ionizing
radiation. First, there are electromagnetic waves, these
types of waves have high frequencies, with the ability to
break chemical bonds in which energy is released,
effectively removing electrons or destroying the nucleus of
the atom. Of the spectrum X-rays and Gamma-rays are
located in the high frequency range. Exposure to these
types of radiation can lead to severe tissue damage.
Secondly, there are particles which are comprised of
protons, electrons, and neutrons. These types of ionizing
particles are alpha and beta particles. (3)
i. X-rays – These are high energy waves, which fall
after UV light on the EM spectrum. These are used
by doctors and scientist of observe internal
structures of the human body, such as bones, as well
as cosmic gases.
ii. Gamma-rays – These waves have the highest
energy in the EM spectrum. Radiation given off
from an atom undergoing radioactive decay. Have a
high penetrating power, which can pose external
and internal health hazards, and require lead or steel
to shield the source.
iii. Alpha particles - These particles are identical to the
nucleus of helium atoms (2 protons + 2
neutrons).This type of radiation has a very short
range and can be shielded with a thin sheet of paper.
They cannot penetrate the first outer layers of skin,
posing no serious external radiation hazards,
however, if inhaled or ingested they can give way to
serious health risks. (4)
iv. Beta particles - These particles are common
products of the radioactive process of nuclear
fission, they occur naturally in radioactive decay
process, and are comprised mainly of electrons.
Beta particles are less ionizing than alpha particles,
but can travel further and penetrate skin or tissue.
This type of radiation is still hazardous as it can
cause damage to internal organs or living cells. (4)
C. Chart of Wavelengths
Radiation Type
Extremely Low Frequency
Very Low Frequency
Radio
Microwaves
Infrared
Visible Light
Ultraviolet
X-rays
Gamma rays
D. X-Rays vs. Gamma Rays
Wavelength
100,000 km – 10,000 km
100 km – 10km
10km – 1dm
1dm – 1mm
1mm – .7µm
700nm – 400nm
400nm – 100nm
10 nm – 0.01nm
0.1nm – 0.001nm
i. Both are classified as high ionizing radiation; however they differ in how
each is produced. X-rays originate from the clashing of electrons onto a
target, or the result of rearrangement. Gamma Rays form as a product of
radioactive decay from nucleus of radionuclide. (4)
E. Units of Measurement for Radiation
i. There are many different techniques and methods used today for assessing
radiation levels. Surveys and measurements from ground and air can be
taken to find the amount of contamination within the soul and
environment around us. Using radiochemical methods, samples from the
ground (soil, vegetation, and crops) can be analyzed to determine the type
and amount of radiation present. (5)
ii. Units of Measurement (5)
Type of
What is it used
Measurement
for?
Biological Risk Measuring the
risk that
someone can
endure from
radiation
exposure
Absorbed Dose Measured by
the amount of
energy
deposited per
weight of
human tissue
Emitted
Measuring
Radiation
how much
radiation
comes from a
radiation
source
International
System (SI)
Sievert (Sv)
Conventional
System (U.S.)
Rem
100 rem = 1 Sv
Gray (Gy)
Rad
100 rad = 1 Gy
Becquerel (Bq)
Curie (Ci)
1 uCi = 37,000 Bq
F. Earth’s Orbit and its Effects on Exposure to Radiation
i. It takes about 24 hours for a complete rotation on its axis and bout 365
days for earth to complete a revolution.
ii. Earth is closer to the sun in the summer of the southern hemisphere and
winter of the northern hemisphere. During these periods of time, the
Earth’s surface receives more solar energy. Countries of the middle
latitudes are exposed to more solar energy in the summer due to the suns
location of being nearly overhead which, in turn, contributes to the longer
duration of the day. Summer, in these countries, has the longest duration
of sun exposure. The worst times of day are between 10 a.m. and 4 p.m.
G. Biological Effects of Radiation
i. Ultraviolet Radiation
1. When UV light hits the skin, damage occurs at a molecular level.
The DNA selections that have thymine nucleotides next to each
other undergo a reaction (breaking and forming bonds). The two
thymine pairs for a dimer (two molecules together) which in turn
forms a kink in the DNA. This kink can disrupt the replication of
new DNA or produce mutated DNA when copied. When new cells
are made from the mutated copy of DNA, these new cells can be
irregular; many of these together can produce harmful irregularities
on the skin. (6) (7)
ii. Ionizing Radiation
1. Ionizing radiation can break or form new chemical bonds, such as
double stranded DNA breaks, during which free radicals (highly
reactive molecules) can be formed. This is done through the loss of
electrons from the molecule as it is “ionized.”(8)
2. Collision of ionizing radiation in cells produces hydroxyl radicals
(8)
3. Stop cell reproduction, by inhibiting key cell structures (organelles
such as mitochondria). (9)
4. Cell death can result from high or frequent exposure from ionizing
radiation. If cell death is not a result of the mutation caused by
radiation then new mutated cells can be produced uncontrollably
when the cell undergoes mitosis. The results of this cell can be
potentially cancerous. (9)
II.
Sources of Exposure to Radiation
A. Background/Naturally Occurring
i. Radon (10)
1. This is the largest source of natural radiation exposure to humans
2. Passes through air space through soil and rock
3. Pressure differences can move the gas indoors
4. 200 millirems (mrem) of radon exposure on average per American
ii. Isotopes (11)
1. Potassium & carbon, the body cannot differentiate between
radioactive & non-radioactive particles
iii. Terrestrial radiation (11)
1. Accounts for 8% of radiation (27 mrem) Americans are exposed to,
annually.
2. High-energy particles bombard Earth’s atmosphere as Earth travels
through space.
B. Medical Process (11)
i. Diagnosis
1. Nuclear tracers (injected into the blood stream)
2. X-rays
ii. Therapy and Treatments
1. Cobalt irradiation (a treatment for cancer)
2. Radiation Therapy
iii. 15% of annual exposure (53 mrem)
C. Abnormal/Man Made (11)
i.
ii.
iii.
iv.
v.
vi.
vii.
Nuclear Power
Neon signs
Smoke detectors
Tanning beds
Airport scanners
Gas mantels
Consumer products
1. Tobacco
2. Natural Gas
3. Phosphate fertilizers
4. Brick or stone
5. Ceramics
D. Prevention
i. There are three basic strategies to prevent and protect against unnecessary
exposure to radiation: (12)
1. Reduce the time you are exposed to the radiation source; the dose
amount is directly proportional to the amount of exposure time.
2. Increase the distance between yourself and the radiation source;
exposure decreases rapidly as the distance between person and
source increases.
3. Increase shielding between yourself and the radiation source;
placing a heavy material between your person and source will
reduce the amount of exposure.
ii. Microwave Oven:
1. “Microwaves are reflected, transmitted, or absorbed by material in
their path.” (13)
2. Microwave ovens are built to contain these waves within the
device, and generally will not work if the latch isn’t closed.
3. To prevent unnecessary leaks, insure that the seals remain clean,
there are not visible signs of damage to the outer shell, and that the
manufactures recommendations are followed.
iii. Ultraviolet Light: (14)
1. Limit midday sun exposure by short time in the sun
2. Find shade
3. Wear protective clothing, sunglasses, hats, and sunscreen
4. Avoid the use of tanning beds
5. Apply sunscreen frequently
iv.
III.
X-rays: (12)
1. Never put any part of your body in the expected path of the main
beam.
2. Avoid being around the X-ray source as much as possible
3. Keep the enclosure doors closed whenever possible
4. When getting medical X-rays protect the parts that aren’t under xray with a heavy material
Uses/Effects
A. Beneficial Applications of Radiation (Health, Industry, Etc.)
i. Radio Waves
1. Data Transmission
ii. Microwaves (13)
1. TV broadcasting
2. Radar – air & sea navigation
3. Telecommunications
4. Processing materials
5. Diathermy treatment
6. Cooking Food
iii. Ultraviolet Radiation
1. Stimulated Vitamin D production, aids in bone growth with
presence of calcium
2. Solar Energy
3. Treatment of Psoriasis
iv. X-rays
1. Used in medical field to observe internal structures, such as bones
2. Used in surgeries for accurate positioning
3. Diagnostic tool (CT or CAT scans)
4. Viewing contents of bags in airports
v. Gamma Radiation
1. Can be useful for sterilization of medical equipment as it can kill
all microorganisms present
2. Gamma-rays are effectively used as tracers in research sciences
3. Can be used as gauges for density and thickness monitoring
4. Used in food preservation to extend self-life and pasteurization
5. Very portable and require only a small amount of radioactive
material
vi. Carbon Dating
1. Used for determination of ages of fossils and other objects, through
analyzing radioactive decay
vii. Radiotherapy (15)
1. Kills cancerous cells to cure cancer or alleviate symptoms
2. Designed to maximize the relief and effectiveness while
minimizing side-effects.
viii. Radioactive material (11)
1. Smoke Detectors used Americium-241 to detect smoke particles in
the air.
2. Sterilize products (cosmetics and medical supplies)
3. Shrink-wrap packaging
B. Hazards of Radiation Exposure
i. Radioactive Iodine (16)
1. Iodine concentrates in the thyroid, body cannot tell difference
between radioactive iodine and non-radioactive.
2. Radioactive iodine can induce mutations leading to thyroid cancer.
ii. Radon (17)
1. Settles in low spaces, such as basements and passes through
crevasse easily.
2. Concentrates in the lungs and induces mutations which can cause
lung-cancer.
iii. Other radioactive material such as strontium and radium can accumulate in
the bone tissue, leading to cancer. (18)
iv. Ionizing Radiation
1. Increased breast cancer risk has been seen in young women
exposed to high cumulative doses of x-ray exposure (19)
2. Leukemia and lung cancer seem more likely than other types of
cancer to be produced by radiation (20)
3. At a more molecular level, ionizing radiation can induce damage in
DNA, gene expression, mobilization of repair proteins, activation
of cytokines, and disrupt remodeling of cellular microenvironment.
(21)
v. Nuclear fallout from events such as the Chernobyl nuclear reactor
meltdown (23) and the incidents that took place in Japan during WWII
lead to environmental changes:
1. Soil contamination
2. Crop contamination
3. Water contamination
vi. Radiation is also a known carcinogen that can cause teratogen mutations,
these mutations are induced by agents that disrupt the development of
embryos and fetuses and can result in birth defects.
vii. Mild exposure of radiation and cause acute radiation sickness, effects and
symptoms include: (18)
1. Blood chemistry changes
2. Nausea
3. Fatigue
4. Vomiting
5. Hair loss
6. Diarrhea
7. Hemorrhages
8. Internal Bleeding
9. Damage to the central nervous system
10. Loss of consciousness
11. Death
IV.
Model Systems for Studying the Effects of Radiation
A. Model systems are great for studying effects of different types of processed.
These systems mimic results that are similarly seen in human models. They are
better for use than humans because these systems grow quickly, are kept easily,
provide sufficient number of offspring and are relatively cheap to keep. (22)
Some common model systems used are:
i. Mice share 99% of genes that humans have. They are easily raised and can
have their DNA altered to express genes have might pose problems in
humans. They are easy to keep and have contributed to many
developments in science.
ii. Cell lines are a good way to preserve a set of cells. These cell lines are
distinct cells grown in culture, normally from a donor. The cells can live
for an extensive amount of time and typically are clones. Cell lines are
great for studying different aspects of illness and disease and have been
used for many years to help contribute to biological developments and
applications.
V.
Statistics Related to Radiation’s Health Effects on Humans
A. The average annual radiation dose that Americans receive is around 400 millirems
(mrems).
i. 50% of the population would die within 30 days of receiving a dose
between 350,000 to 500,00 mrem. (24)
ii. Exposure comes from a variety of sources: (11)
1. Radon – 200mrem (55%)
2. Inside Human Body – 40mrem (11%)
3. Rocks & Soil – 28mrem (8%)
4. Cosmic – 27mrem (8%)
5. Medical/Dental X-rays – 39mrem (11%)
6. Nuclear Medicine – 14mrem (4%)
7. Consumer Products – 10mrem (3%)
8. Other Sources (<1%)
B. Radiation and cancer
i. Illness
1. In a group of 10,000 who are exposed to 1 rem of ionizing
radiation (in small doses over a lifetime) 5 or 6 more people to die
of cancer than would otherwise. (18)
2. Of this group, 2,000 are expected die of cancer from all nonradiation causes. (18)
3. 50% and 90% of skin cancer are due to UV raduation. (14)
4. 18 million people worldwide are blind from cataracts, 5% may be
due to UV radiation. (14)
ii. Therapy Statistics: (25)
1. Patients of breast cancer, prostate cancer, and lung cancer account
for more than half (56%) of all those receiving radiation therapy.
2. Radiation therapy will be used in almost 2/3 of all cancer patients
treatments
C. Historical Data
i. 1986 – Chernobyl nuclear reactor incident: 134 people received radiation
doses of 80,000-1,600,000 mrem and suffered from acute radiation
sickness; of these 28 died within 3 months of the accident. (24)
ii. 10 years before the Chernobyl incident: In Belarus 1,342 adults and 7
children were diagnosed with thyroid cancers. (23)
iii. 9 years after the Chernobyl incident: In Belarus 4,006 adults and 508
children were diagnosed with thyroid cancers. (23)
VI.
Resources
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[http://www.eoearth.org]
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[http://www.evs.anl.gov]
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[JSTOR]
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(2009): 6-12 [PUBMED]
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