Slides-Radiation. Radiation X-ray and hazard and health effect in Radiology11.08.10.ppt

Radiation X-ray and hazard and health effect in Radiology

1. A Small Dose of Radiation – 11/08/10
Prepare by
Bilal Sabíu
Radiation Hazards and Health Effects

2. A Small Dose of Radiation – 11/08/10 A Small Dose of Toxicology
What is radiation?
The emission of energy in the form of waves or particles.
What is ionizing radiation? High-energy radiation that can knock
electrons off atoms, creating ions. This is the type of radiation that poses
the greatest health risk.
Sources of radiation:
Natural: Cosmic rays, terrestrial sources (uranium in soil), and radon
gas.
Man-made: Medical procedures (X-rays, CT scans), nuclear power, and
industrial applications.
Purpose: To explain the risks of radiation exposure and the health
effects on the human body.
Introduction

3. A Small Dose of Radiation – 11/08/10 A Small Dose of Toxicology
Types of Ionizing Radiation
•Alpha particles: Heavy, positively charged
particles. They have low penetrating power and
can be stopped by a sheet of paper. The hazard is
primarily from internal exposure (inhalation or
ingestion).
•Beta particles: Light, negatively charged particles.
They have greater penetrating power than alpha
particles but can be stopped by plastic or
aluminum. Internal exposure is also a concern.
•Gamma rays: High-energy electromagnetic
waves. They have high penetrating power and
require thick shielding (e.g., lead or concrete).

4. A Small Dose of Radiation – 11/08/10 A Small Dose of Toxicology
Continuous
•X-rays: Similar to gamma rays, but typically
lower in energy. Produced by electronic
processes.
•Neutrons: Neutral particles that can cause other
atoms to become radioactive. Shielding requires
materials rich in hydrogen, such as water or
concrete.

5. A Small Dose of Radiation – 11/08/10 A Small Dose of Toxicology
Biological Effects of Radiation
•Radiation interacts with the body at the cellular
level.
•It can damage DNA, potentially leading to cell
death or uncontrolled cell division (cancer).
•The effects depend on several factors:
•Dose: The amount of radiation received.
•Dose rate: How quickly the radiation is delivered.
•Type of radiation: Alpha, beta, gamma, etc.
•Part of the body exposed: Some organs are more
sensitive than others.

6. A Small Dose of Radiation – 11/08/10 A Small Dose of Toxicology
Deterministic (Threshold) Effects:
Occur at high radiation doses, above a certain threshold.
Severity increases with the dose.
Result from the death of many cells in a tissue or organ.
Examples: Acute Radiation Syndrome (ARS), skin burns,
hair loss, and cataracts.
Stochastic (Non-threshold) Effects:
Occur at low radiation doses.
The probability of occurrence increases with dose, but
severity is not dependent on dose.
Result from damage to a single cell.
Examples: Cancer and heritable (genetic) effects.
Classification of Health Effects

7. A Small Dose of Radiation – 11/08/10 A Small Dose of Toxicology
Acute Radiation Syndrome (ARS)
Also known as radiation sickness.
Occurs after a high dose of radiation to the whole
body over a short period.
Symptoms vary based on dose:
Initial symptoms (prodromal stage): Nausea,
vomiting, and diarrhea.
Higher doses can lead to: Damage to the bone
marrow, gastrointestinal tract, and central
nervous system, which can be fatal.
•.

8. A Small Dose of Radiation – 11/08/10 A Small Dose of Toxicology
Long-Term Health Effects
Cancer: An increased risk of developing
cancer, such as leukemia, is a well-
documented stochastic effect of radiation
exposure.
Hereditary Effects: While less common,
radiation damage to reproductive cells can
potentially cause genetic mutations that may
be passed to future generations.
Cataracts: High radiation exposure to the
eyes can lead to the formation of cataracts.
rays

9. A Small Dose of Radiation – 11/08/10 A Small Dose of Toxicology
Radiation Protection Principles
Justification: The radiation exposure must
provide a net benefit to the individual or
society.
Optimization (ALARA): Exposure should be
"As Low As Reasonably Achievable," taking
into account social and economic factors.
Dose Limitation: Individual doses should not
exceed specified limits.
 

10. A Small Dose of Radiation – 11/08/10 A Small Dose of Toxicology
Practical Radiation Protection
Measures
Time: Minimize the time spent near a
radiation source.
Distance: Increase the distance from the
radiation source. Inverse Square Law applies
(doubling the distance quarters the dose).
Shielding: Use appropriate materials to block
radiation (e.g., lead aprons, concrete walls).
Containment: For radioactive materials,
prevent their spread through containment.

11. A Small Dose of Radiation – 11/08/10 A Small Dose of Toxicology
Conclusion
Radiation is a natural and man-made phenomenon
with both beneficial and harmful effects.
Understanding the types and sources of radiation is
crucial for managing health risks.
Adherence to radiation protection principles
(Justification, ALARA, and Dose Limitation) is
essential for safety.
Continuing education and awareness are key to
minimizing radiation hazards.
 

12. A Small Dose of Radiation – 11/08/10 A Small Dose of Toxicology
World Health Organization (WHO). "Radiation and health." www.who.int/news-
room/questions-and-answers/item/radiation-and-health.
International Atomic Energy Agency (IAEA). "Radiation Protection and Safety of
Radiation Sources." www-pub.iaea.org/MTCD/Publications/PDF/Pub1578_web-
57265295.pdf.
U.S. Nuclear Regulatory Commission (NRC). "Biological Effects of Radiation."
www.nrc.gov/reading-rm/basic-ref/students/for-educators/09.pdf.
National Center for Biotechnology Information (NCBI). "Radiation Safety and
Protection." www.ncbi.nlm.nih.gov/books/NBK557499/.
ResearchGate. "Radiation Exposure and Health Effects – is it Time to Reassess
the Real Consequences."
www.researchgate.net/publication/294423799_Radiation_Exposure_and_Health_
Effects_-_is_it_Time_to_Reassess_the_Real_Consequences.
Atomic Energy Regulatory Board (AERB). "Diagnostic Radiology Biological Effects
of Radiation." www.aerb.gov.in/images/PDF/TrainingModule/2-BIOLOGICAL-
EFFECTS-OF-RADIATION-AND-OPERATIONAL-QUANTITIES.pdf.
References