1. Radiation

2. Radiation
Radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium
Ionizing Radiation: It is the radiation that has ability to penetrate tissues and deposit its energy within them alpha rays, beta rays, x-rays
Non-Ionizing Radiation: It has not sufficient energy to ionize matter like UV, Visible light

3. Sources of radiation Cosmic rays Environmental Internal body
Natural(Background)
Medical (x-rays)
Agricultural
Industries
Defense
Miscellaneous
Artificial

4. Natural Sources Cosmic rays: Originate in outer space
Environmental: It can be from terrestrial source like uranium, radium, thorium present in rocks and buildings
Internal from carbon-14 radioactive isotope present in living matter
These are “Background radiation”

5. Radium and Radon Hazards
These are important contributors to environmental radioactivity
Radon is 2% contributor of all cancer related deaths in Europe
Well & rain water can be very rich in radon
Epidemiological evidence shows a clear link between lung cancer and high concentrations of radon (EPA, 2003)
Radon concentration is usually measured in the atmosphere in Becquerel per cubic meter (Bq/m3)

6. Artificial Sources (Medical)
Radiation have saved thousands of lives through the detection and treatment of conditions ranging from hyperthyroidism to bone cancer
Computed tomography (CT) scanners
Nuclear medicines (radiotracers)

7. Artificial sources (Agriculture)
Radioisotopes were used for producing high yielding crop seeds to increase the agricultural yield
Radiations from certain radioisotopes were also used for killing insects which damage the food grains

8. Artificial Sources (Daily routine)
Nonstick cookware is treated with gamma rays to keep food from sticking to the metal surface
Reflective signs that have been treated with radioactive tritium and phosphorescent paint
Television, mobiles, luminous watches

9. Artificial Sources (Defense)
At air ports use of cabinet x-ray system
Nuclear weapons (Fission Bombs)
Thermonuclear weapons
Nuclear fall outs or nuclear accidents
Chernobyl disaster in USSR 1986
Fukushima disaster in Japan 2011

10. Units of Radiation
Radiation equivalent man(Rem): It shows biological impact
Absorbed radiation dose (Rad): It is unit of absorbed dose per gm of tissue
Sievert (Sv): unit of absorbed radiation dose. Mostly in milli and micron

11. Some other units
Relative Biological Effectiveness (RBE): is the ratio of biological effectiveness of one type of ionizing radiation relative to another
Bacquerel

13. Immediate Effects Radiation Sickness Acute radiation syndrome Alopecia
Removal of sub-cutaneous fat
Dark complexion
Softening of muscles

14. Delayed Effects Leukemia Carcinogenesis
Fetal development abnormalities
Shortening of life
Teratogenesis

16. Half Life??

17. Why it is a Public Health issue??

18. Radiation Dose
The individual dose limit for radiation workers averaged over 5 years is 100 mSv, and
For members of the general public, is 1 mSv per year.

19. Protection Measures
According to International Commission on Radiological Protection (ICRP):
Limit time for exposure
Reduce distance
Use of protective shields
Avoid unnecessary x-rays
Spend time in open atmosphere
Radiation dosimeters

20. Radioactive wastes
Type A: The radioactive waste from laboratory and academic institutions and decay in almost 100 years
Type B: Medium radioactive material from nuclear plants and retain decaying activity for almost 300 years
Type C: High level radioactive waste from nuclear plants and accidents and remained as it is for >300 years

21. Methods of Radioactive Wastes Disposal
Reprocessing and energy reclamation
Cooling and solidification
Deep thick concrete trench disposal
Geological isolation in mines or deserts

22. Reference:
International atomic energy agency (IAEA)