a small presentation about radiation.

1. radiation

2. What is radiation?
• Radiation is energy that travels in waves. It includes visible light,
ultraviolet light, radio waves and other forms, including particles.
• Each type of radiation has different properties. Non-ionizing radiation can
shake or move molecules.
• Ionizing radiation can break molecular bonds, causing unpredictable
chemical reactions.
• Ionizing radiation includes not only energy waves but particles as well.
• Humans cannot see, feel, taste, smell or hear ionizing radiation.
Unavoidable exposure to ionizing radiation comes from cosmic rays and
some natural material.
• Human exposure to natural
radiation is responsible
for a certain number of
mutations and cancers.
Additional exposure above
natural background radiation is
cause for concern since it may
result in otherwise preventable
disease.

3. Types of radiation
• Alpha particles consist of two protons and two
neutrons, in the form of atomic nuclei. Alpha
particles are doubly charged (arising from the
charge of the two protons). This charge and the
relatively slow speed and high mass of alpha
particles means that they interact more readily with
matter than beta particles or gamma rays and lose
their energy quickly. They therefore have little
penetrating power and can be stopped by the first
layer of skin or a sheet of paper. But inside the body
they can inflict more severe biological damage than
other types of radiation.

4. Beta particles are fast-moving electrons
ejected from the nuclei of many kinds of
radioactive atoms. These particles are singly
charged (the charge of an electron), are
lighter and ejected at a much higher speed
than alpha particles. They can penetrate up
to 1 to 2 centimetres of water or human
flesh. They can be stopped by a sheet of
aluminium a few millimetres thick.

5. Gamma rays
Gamma rays, like light, represent energy transmitted in a wave without
the movement of material, just like heat and light. Gamma rays and X-
rays are virtually identical except that X-rays are produced artificially
rather than coming from the atomic nucleus. But unlike light,
these rays have great penetrating power and
can pass through the human body.
Mass in the form of concrete,
lead or water is used to shield
us from them.

6. Radioactive things in daily life

7. •Youprobablyalreadyknewthatbananasareloadedwith
potassium.Butbananasalsohappento be oneof themost
radioactivefoodsbecausetheycontainthe isotopepotassium-40.
Thanksto this isotope,everyone’sfavouriteyellowfruit emitsa
tinyamountof radiation.MuchliketheBrazil nuts,the
radioactivepotassiumis takenup in the soil andabsorbedby the
fruit.
•Bananasaresucha commoneverydaysourceof radiationthat
there’sevenan unofficial unit of measurement forradiationcalled
the BED, or Banana Equivalent Dose,that’susedto illustrate
foods’radiationlevels.

8. Brazil nuts (especially the ones grown in Brazil) grow
on trees with deep roots, which reach down to soil
high in natural radium, a source of radiation. The
roots absorb the radium, which then makes its way
to the nuts. As a result, the radium levels of Brazil
nuts can be 1000 times what you’d see in other foods.
Luckily, the EPA regulates food radiation levels like
these, so you should have a wide margin of error for
safe snacking.

9. Granite naturally contains uranium and thorium,
because those elements are found in the magma
that solidified to make it. But the real concern is
radon. The naturally-occurring uranium decays
into radon, which is a gas. And just like you
shouldn’t be breathing in the powdered contents
of smoke detectors, radioactive gases can be
inhaled and cause health issues. But as far as
kitchen islands go, granite is a fairly safe choice—
it’s not too porous, which means that more of
that radon is kept inside, according to the EPA.
GRANITE

10. Smoke detectors
Some household smoke detectors use tiny amounts of
a radioactive isotope, americium-241, to alert you
when there’s smoke in the air. The material is
surrounded by ceramic and foil, so it doesn’t pose any
harm to you so long as you don’t go tinkering with
the detector. (But even then, unless you ground it up
and swallowed the powder, you’d probably be fine.)

11. Modern watches and clocks sometimes use
a small quantity of hydrogen-3 (tritium) or
promethium-147 as a source of light. Older
(for example, pre-1970) watches and clocks
used radium-226 as a source of light. If
these older timepieces are opened and the
dial or hands handled, some of the radium
could be picked up and possibly ingested. As
such, caution should be exercised when
handling these items.

12. Glassware, especially antique glassware with a yellow
or greenish colour, can contain easily detectable
quantities of uranium. Such uranium-containing glass
is often referred to as canary or Vaseline glass. In part,
collectors like uranium glass for the attractive glow
that is produced when the glass is exposed to a black
light. Even ordinary glass can contain high-enough
levels of potassium-40 or thorium-232 to be
detectable with a survey instrument. Older camera
lenses (1950s-1970s) often employed coatings of
thorium-232 to alter the index of refraction.

13. fertilizers
• Commercial fertilizers are designed to provide
varying levels of potassium, phosphorous, and
nitrogen. Such fertilizers can be measurably
radioactive for two reasons: potassium is
naturally radioactive, and the phosphorous
can be derived from phosphate ore that
contains elevated levels of uranium.

18. The radiation in cigarettes doesn’t come
from the chemical additives smokers are
warned about; it actually comes from the
tobacco itself. In a process similar to how
bananas and Brazil nuts become radioactive,
tobacco plants can absorb radioactive
elements such as radium, lead-210, and
polonium-210 from some fertilizers used on
crops.
Cigarettes

19. Cat litter
• Cat litter is sufficiently radioactive that it can set
off radiation alerts at international border
checkpoints. Actually, it's not all cat litter you
need to worry about -- only the stuff made from
clay or bentonite. Radioactive isotopes naturally
occur in clay at the rate of about 4 pCi/g for
uranium isotopes, 3 pCi/g for thorium isotopes,
and 8 pCi/g of potassium-40. A researcher at Oak
Ridge Associate Universities once calculated
American consumers buy 50,000 pounds of
uranium and 120,000 pounds of thorium in the
form of cat litter each and every year.

20. Grand central station,NYC
New York City’s Grand Central Station is one of the largest railway
stations in the world. It’s also, as many of the commuters that pass
through it might be worried to know, one of the most radioactive.
This is because many of
the walls of the station,
as well as its foundations,
were built using granite,
a rock capable of holding
natural radiation. In fact,
the radiation levels produced
by the station are so high that
they actually exceed the levels
that nuclear power plants are
legally allowed to emit.

21. Magazine covers
If a magazine publisher wants to blow some money, it might start
printing onto glossy paper, mainly because it looks nicer, but also
because they think consumers are part-magpie and therefore more
likely to buy something if it’s shiny.
However, getting paper to look that sleek and
glossy requires it to be covered in kaolin,
a type of white clay. Like the clay that forms
kitty litter, this clay is also capable of holding
radioactive elements such as uranium and
thorium. This clay is also used commonly as a
food additive and as an ingredient in many
over-the-counter drugs.