NINSIIMA LYNN

RPO, ATOMIC ENERGY COUNCIL

BASICS OF RADIATION, HEALTH EFFECTS AND PRINCIPLES

A presentation to radiation workers

November 11, 2016

Presentation Outline

• Introduction

• Radiation

• Types of Radiation

• Sources of Radiation

• Exposure Situations

• Effects of Ionizing Radiation

• Principles of Radiation Protection

2

Radiation

Forms of radiation

Any type of electromagnetic radiation that does not carry enough energy per to ionize atoms or molecules—that is, to completely remove an electron from an atom

eg RF, Infra-red, microwave

Forms of radiation (2)

• Ionizing radiation is radiation that has sufficient energy to remove electrons from atoms

• Radiation is invisible and not detectable by human senses

• Ionizing radiation can cause damage to human DNA (human health) and environment

• Radiation can be detected by use of instruments and detectors

AEC currently regulating ionizing radiation,

Intends to regulate non-ionizing radiation

Types of Ionizing Radiation• Alpha

• Beta

• Gamma

• Neutrons

• Energy

• Penetrating power

• distance

Sources of Ionizing Radiation exposure

• Natural SourcesNatural Background

Terrestrial

Cosmic

Cosmogenic

NORMs

• Artificial sourcesMedical

Industrial

Consumer products

Modes of Exposure to Radiation

Applications of Ionizing Radiation in Uganda

• MedicalRadiologyNuclear MedicineRadiotherapy

• Industrial Non Destructive Tests

Industrial Radiography

Well logging

Nuclear gauging

Level gauges

Fixed gauges

• Agriculture

Tsetse fly irradiation

• Research & Education

Analytical studies

Exposure Situations

1. Planned Exposure Situations

• Occupational exposures

• Medical Exposures

• Public exposures

2. Emergency exposure Situations

• Occupational exposures

• Public exposures

3. Existing exposure situations

• Public exposures

Effects of ionizing radiation

Stochastic Effects

Probability of occurrence is a function of dose

Severity is not a function of dose

No threshold dose

• Cancer

• Hereditary effects

• Leukemia

Deterministic (Non-Stochastic Effects)

Severity of effect varies with dose

a threshold dose exists

usually after large absorbed doses of radiation (~1-2 Gy)

• Erythema (skin reddening)

• Sterility

• Cataracts

• Death

• Hair loss

Some Visual Effects of Nuclear Disasters

Some Visual Effects of Nuclear Disasters

Principles of Radiation Protection

• The ALARA Principle:

ALARA stands for As Low As Reasonably Achievable. It is the basic principle of radiation protection procedures.

• The three factors influencing radiation dose are:

ALARA - Time• The less time you’re exposed, the less exposure you receive

• Dose = Dose Rate x Time

• Limit your time near the radiation source!

• Operators should not exceed recommended workload.

Measure of radiation output per week (mA-min)

Dose, number of patients, type of practice, time

ALARA - Distance

• The farther away from the source you are, the weaker the

source is to you

• Exposure levels are based upon the Inverse Square Law

• Increase the distance between you and the source!

• Keep the tube away from the working area/ control cubicle

• Utilize the size of the imaging room

profitably.

ALARA - Shielding

• Shielding can reduce or stop radiation from reaching you

• Increase the amount of shielding material

between you and the source!

• You should never work in the primary beam

• Permanent control cubicle must have properly fitted lead glass of appropriate thickness

1. Understand and apply the cardinal principles of radiation control: time, distance and shielding.

2. Do not allow familiarity to result in a false security.

3. Never stand in the primary beam.

4. Always wear protective apparel when not behind a protective barrier.

5. Always wear a radiation monitor and position it outside the protective apron at collar level.

6. Never hold a patient during radiographic examinations. Use mechanical restraining devices when possible. Otherwise, use patients or friends to hold the patient.

Ten Commandments of ALARA

Ten Commandments of ALARA (2)

7. The person holding the patient must wear protective

apron and if possible, gloves.

8. Use gonadal protective on all people of childbearing age

when it will not interfere with the examination.

9. Examinations of the pelvis or lower abdomen of a

pregnant patient should be avoided whenever possible,

especially during the first trimester.

10. Always collimate to the smallest field size appropriate to

the examination.

THANK YOU