Introduction of radiation, hazards and Measuring Equipment used in Radiation Protection. Biology Effects. Nuclear effects. Different Radiation Measuring instruments. 1.Types of personnel monitoring devices 2.Instruments for measuring external Exposure.

1. SABIR RASHEED
Radiation’s Introduction, Hazards and Measuring Equipment’s
used in Radiation Protection.

2. Agenda
Introduction
01
Hazards
02
Instruments
03

3. Definition
Radiation is the emission and propagation of Energy in the form of
waves, rays or particles.

4. Units

5. • Infographic Style
Examples
A burning candle Uranium-238 decay
Uranium-238 decaying
into Thorium-234
emits radiation in the
form of alpha particles.
A burning candle emits
radiation in the form of
heat and light.

6. Types of Radiation
Three Types of Radiations
Non-
ionizing
radiation
Ionizing
radiation
Neutrons

7. Protection
• Why?
• From What?
• Whom to protect?
• How to protect?

8. How
dangerous is
nuclear
radiation?

9. Is There
RADIATION
in this
Lab/Classroom?

10. Radiation - We live with
Natural Radiation:
Cosmic rays, radiation within our body, in food we eat, water we drink,
house we live in, lawn, building material etc.
Human Body:
K-40, Ra-226, Ra-228
e.g. a man with 70 kg wt.
140 gm of K
140 x 0.012%
0.0168 gm of K-40
0.1 Ci of K-40

11. Radiation – We travel with

12. Radiation - We eat with
Food Radioactive levels (Bq/kg)
Daily intake
(g/d)
Ra-226 Th-228 Pb-210 K-40
Rice 150 0.126 0.267 0.133 62.4
Wheat 270 0.296 0.270 0.133 142.2
Pulses 60 0.233 0.093 0.115 397.0
Other Veg
etables
70 0.126 0.167 -- 135.2
Leafy
Vegetables
15 0.267 0.326 -- 89.1
Milk 90 -- -- -- 38.1
Composite
Diet
1370 0.067 0.089 0.063 65.0
Dose equivalent=0.315 mSv/yr
Total dose from Natural sources = 1.0 to 3.0 mSv/yr

14. Electromagnetic Waves
Low High
ENERGY
Radio
waves
Microwaves
Radar
Infrared
Visible
light
Ultra-violet
X-ray
Gamma-ray
Non-ionizing radiation
Ionizing radiation

15. DO WE NEED
RADIATION
PROTECTION ?

16. Case study I: Chernobyl, Ukraine
• On April 25, 1986, the “Chernobyl 4 reactor crew” started a test to determine the “turbine’s operating time” and
available “power” due to loss of the main power supply. The reactor was in a very unstable state when the operator
decided to shut it down. Due to the interaction of very hot fuel with cooling water, the fuel fragmented, steam was
produced, and pressure increased. The overpressure caused a partial loosening of the 1000-ton cover plate of the
reactor, which caused the breakage of the fuel channels and the blockage of all control rods, which were halfway
down.
• It is estimated that all the “xenon gas,” about half the “iodine” and “cesium,” and a minimum of 5% of the
“radioactive material” were released into the “Chernobyl reactor core” during the accident.
• The first days’ radiation doses were at 20,000 millisieverts (mSv) and killed 28 people, including six firefighters.
• Around five million people lived in contaminated areas 400,000 lived in more effected areas under strict
regulatory control.
• On May 2 and 3, 1986, about 45,000 residents from areas of the city of Pripyat within 10 km of the plant were
evacuated.

18. Case study II: Fukushima, Japan
• The 9.0 magnitude earthquake in “Eastern Japan on Friday, March 11, 2011 at 2.46 p.m.” caused significant
damage to the region, and the great “tsunami” that followed the earthquake caused much more.
• The earthquake was 130 km off the coast of the “city of Sendai, in the Miyagi prefecture, on the East coast of
Honshu Island” and was a rare double complex earthquake with a severe duration of approximately 3 min.
• The tsunami flooded about 560 km2, leaving around 19,000 people dead and widespread damage to portsand
coastal town.
• More than one million buildings were destroyed or partially collapsed

20. Effect on Human Health

21. Biological Effects of radiation
Exposure above permissible levels may result in:
Somatic Effects
Physical effects
May be immediate or delayed
Genetic Effects
Birth defects due to irradiation to reproductive cells before conception
Teratogenic Effects
Cancer or congenital malformation due to radiation exposure to fetus in uteo

22. Biological Effects
-Threshold-
Threshold effects might occur if an individual receives a dose above the
threshold level.
Acute Radiation Syndrome: large whole-body dose in a short time
Effects occur at 100 rad
Radiation-induced cataract formation
Acute effects occur at 200 rad Chronic effects occur at 800 rad
Other thresholds
Severe skin injury occurs at 1,500 rad Teratogenic effects occur at 20 rad

23. Biological Effects
-Non-threshold-
Non-threshold effects might occur from any amount of exposure to
radiation.
Chance of effect occurrence is proportional to the received dose. Severity of effects are not necessarily
related to exposure level.
Chance effects include:
Cancer - estimated to be 5 deaths per 10,000 persons, whom each received 1,000 mrem
Genetic effects

24. Summary of Biological Effects of Radiation
Radiation may…
• Deposit Energy in Body
• Cause DNA Damage
• Create Ionizations in Body
• Leading to Free Radicals Which may lead to biological damage

25. Effect on Nuclear Worker Health

26. Effect on Nuclear Worker Health
Having experienced (Chernobyl, Ukraine & Fukushima, Japan) tragic accidents and being informed
about the harmfulness of exposure to radiation, we begin to think about the health of nuclear power plant
employees who work in nuclear industry spend the most time near nuclear power plant, thus have biggest
change of being exposed to radiation.
It will be examined into to Terms
1. Short-Term Health Effect
2. Long-Term Health Effect

27. Short-Term Health Effect
Nuclear workers to experience short-term health effect due to radiation, the average measurable dose of radiation
exposure per worker is 0.19mSV, way less than the radiation dose.
A short-term health effect due to radiation exposure is something very unlikely to happen unless an accident
occurs in nuclear power plant.
Many of the nuclear power plant workers are more concerned about issues such as fire, explosion, and radiation
leakage, rather than naturally being exposed to radiation during routinely work.
Nuclear power plant must be examined 24 hours, workers must have regular night shifts. Shift workers are very
likely to experience less alertness, more fatigue, sleepiness, and social issues, all increasing the likelihood of an
accident.
In a short- term radiation does not affect workers' health, and health problems of nuclear power plant workers are
similar to those of ordinary workers.

28. Long-Term Health Effects
Long-term health effects caused by radiation are cancer and leukemia. However, those illnesses are more likely to
occur when a person is exposed to a radiation dose of 100mSv or higher in a span of five years.
However, according to the annual report published by Atomic Energy Regulatory Board (AERB) in India, no
nuclear worker exceed the annual dose exposure limit of 30mSv during the year 2015 and earlier years.

29. Radiation health effects
DETERMINISTIC
Somatic
Clinically attributable
in the exposed
individual
CELL DEATH
STOCHASTIC
somatic & hereditary
epidemiologically
attributable in large
populations
ANTENATAL
somatic and
hereditary expressed in
the foetus, in the live
born or descendants
BOTH
TYPE
OF EFFECTS
CELL TRANSFORMATION

30. Radiation Injury from an industrial Source
(Threshold/non-stochastic)
• Existence of a dose threshold value
(below this dose, the effect is not
observable)
• Severity of the effect increases with
dose
• A large number of cells are involved
Deterministic
effects

32. Stochastic Effects

33. SO, WE NEED
RADIATION
PROTECTION!!!

34. Measuring
Equipment

35. Personnel monitoring devices
 Occupational radiation monitoring offers noprotection against exposure.
 It simply measures the quantity of radiation to which monitor was exposed.
 Dosimeters should be obtained from certified laboratory.

36. Types of
personnel
monitoring
devices
1.Film
badge
TLD
badge
OSL
Dosimeter
Pocket
dosimeters

37. 1. Film badges
Come in general use during1947s.
Widely used in diagnosticradiology.
One of the earliest dosimeters and simplylike the packets of
dental x-ray film that was developed occasionally to view
the extent of darkening.
The darker the film the more radiationdose.
Exposure less than 10mR (100μGy) arenot measured by it.
It can detect alpha particle, beta particle,x-rays, gamma rays
, and thermal neutrons.

38. Film Holder
Film is packaged in a light proof, vapor proof
envelope preventing light, moisture or chemical
vapor from affecting the film i.e. film holder.
Holder contains suitable metallic filters fixed on
both side of the holder which help to identify the
type and energy of incident radiation.

39. Film badge consist of stainless steel holder, photographic film and all six filters fixed in
particular window.

40. FILM HOLDER
1st window
Detects alphaparticles .Has openwindow.
Due to low penetration power of alpha
particles no any metallic filter is used.
05
06 01
02
03
04
2nd window
Filter is made up ofplastic. Light white
color. It detects betaparticles. Thickness
of filter is generally 1mm
3rd window
Filter is made up of cadmium. Yellow in
color. It detects the thermal neutrons.
Thickness of filter is 1mm
6th window
Filter is made up of lead. Black incolor.
Detects gamma ray. Thickness of filter
1mm
5th window
Filter is made up of thickcopper. Pink in
color. It detects gamma rays and hardx-
rays. Thickness of the filter1mm
4th window
Filter made up of thincopper. Green in
color. It detects the low energy x-rays.
Thickness of filter is generally 0.15mm
Window

41. 2. Thermoluminescence dosimeter TLD Badge
Thermo-luminescent dosimeter (TLD) badge is used currently instead of film badge
It is based on phenomenon of thermo luminescence, the emission of light when certain material are heated a
fter radiation exposure
In early 1960s, Cameron and co-workers from University of Wisconsin developed the TLD badge, use
to measure individual dose from x ray , beta particles and gamma radiation.
Response isdirectly proportional to the amount of radiation absorbed.
Can detect x-ray, gamma ray and betaparticle.
It can measure exposure as low as 10microsivert.
TLD badge can cover a wide range of the dose from 10 mR to 10000 R with the accuracy of +/-10 percent.

42. 2. Thermoluminescence dosimeter TLD Badge

43. Types of TLD badges
i. Chest badge ii. wrist badge iii. Finger dosimeter

45. 3) Optically stimulated luminescence (OSL)
DOSIMETER
OSL dosimeter have recently become commercially available as an alternative to TLD.
New technology that uses a laser to trapenergy from radiation fields in a tiny crystal.
Stored energy from the radiation releasedfrom the dosimeter material by optical stimulation.
Energy release in the form ofluminescence.
It is more sensitive thanTLD.
Capable to detecting dose as low as 10μSv(1mrem).
Working mechanism is similar to the TLDs except thelight emission is stimulated by laser
light.
Crystalline Aluminum oxide activated with carbon(Al2O3:C) is commonly used.

46. OSL Dosimeter

48. 4) POCKET DOSIMETER
Pocket dosimeters are known by a number of other
names, e.g., direct-reading dosimeters, self-reading
pocket dosimeters and pocket electroscopes..
It can detect x-ray and gammaray.
Named as they are commonly worn in thepocket.

49. DIGITAL ELECTRONIC DOSIMETER
 Type of pocketdosimeter.
 Dosimeter most often useGeiger- Muller counters.
 Some include an audiblealarm feature which emits an
audible signal.

50. 4) POCKET DOSIMETER
Working Principle
They are actually quartz fiber electroscopes the sensing element of which is a movable bow-shaped quartz
fiber that is attached at each end to a fixed post.
The dose is determined by looking through the eyepiece on one end of the dosimeter, pointing the other
end towards a light source, and noting the position of the fiber on a scale.
Their walls might be made of aluminum, bakelite, or some other type of plastic.
If the material was not conductive, the inner surface of the chamber was coated with Aquadag (graphite).
The central electrode was usually a phosphor bronze rod. This made pocket dosimeters more energy
dependent than pocket chambers whose central electrodes were usually aluminum.
Some dosimeters (e.g., Keleket Model K-145) employed boron-lined chambers which made them sensitive
to thermal neutrons.
Pocket dosimeters must be charged (ca. 150 – 200 volts) with some sort of charger.

52. Instruments for measuring external Exposure

53. Ionization chambers
Proportional counter GM counters

54. Ionization Chambers
Working Principle
A well-type ionization chamber is composed of a cylinder containing the gas (nitrogen, argon or gas mixtu
re) under a given pressure and electrodes that will be used to collect electrical charges.
The operating principle of an ionization chamber is simple: ionizing radiation from the source (X- or gam
ma rays, electrons) creates an ionization of the gas atoms.
A voltage is applied between the electrodes.
Negative charges are attracted by the anode, positive charges by the cathode.
The applied voltage (polarization voltage) is high enough to allow the complete collection of positive and
negative ions.
An electric current called ionization current is then established which is proportional to the activity of the r
adioactive source.

56. Proportional Counters
Working Principle
The proportional counter has a cathode and an anode that are held at some voltage (above 1000 V), and
the device is characterized by a capacitance that is determined by the geometry of the electrodes.
In a proportional counter the fill gas of the chamber is an inert gas which is ionized by incident radiation, a
nd a quench gas to ensure each pulse discharge terminates; a common mixture is 90% argon, 10% methan
e, known as P-10.
As ionizing radiation enters the gas between the electrodes, a finite number of ion-pairs are formed.
The behavior of the resultant ion-pairs is affected by the potential gradient of the electric field within the
gas and the type and pressure of the fill gas.
Under the influence of the electric field, the positive ions will move toward the negatively charged
electrode (outer cylinder), and the negative ions (electrons) will migrate toward the positive electrode
(central wire).

58. Geiger Muller Counters
Working Principle
A Geiger counter (Geiger-Muller tube) is a device used for the detection and measurement of all types of
radiation: alpha, beta and gamma radiation.
It consists of a pair of electrodes surrounded by a gas.
The electrodes have a high voltage across them.
The gas used is usually Helium or Argon.
The ionizing particle passing through the tube ionizes the gas and electrons so produced move towards
Anode.
The velocity is quite high and they later produce secondary electrons after repeated collisions with the part
icles of the gas. These secondary electrons further produce more electrons in Geometric progression.

60. Gas-Filled Detector
Characteristics Curve

61. Conclusions
Cardinal principles must be used for protection of
patient and personnel. Radiation monitoring devices
do not provide protection from the radiation; it just
measures the radiation absorbed by an individual.
Modern medicine would be impossible without ionizing
radiation. The committee recognizes both the tremendous
benefits derived from the use of ionizing radiation in
medicine and its potential for harm.