FYI: RADIATIONKristine Marie Romallosa

Radiation Protection Services

Philippine Nuclear Research Institute

Things to know about radiation..

• Ionizing radiation

• Types of ionizing radiation

• Sources of ionizing radiation

• Radioactive materials

What is Radiation?

What is Radiation?

Radiation is the process of

emitting energy through a

medium or space in the form

of waves or particles

What is Radiation?

WAVES PARTICLES

Radiation is the process of emitting energy through a medium or space in the form

of waves or particles

WAVES PARTICLES

NON-IONISING IONISING

What is Radiation?Radiation is the process of emitting energy through a medium or space in the form

of waves or particles

What is Ionizing Radiation?

Type of radiation that has sufficient energy to knock-out

electrons in atoms and molecules

Ionizing radiation

electron

Types of Ionizing Radiation

� Alpha particles

� Beta particles

� Gamma rays

� X-rays

� Neutrons

Types of Ionizing Radiation

Alpha

Beta

Gamma

Alpha

Beta

Gamma

Types of Ionizing Radiation

Radiation Hazards

....alpha & beta emitters are more

hazardous When they are

ingested or inhaled..

....neutrons, x-rays & gamma rays

are more hazardous for the

entire body..

Sources of Ionising Radiation

• Radioactive materials – Radioactive materials continuously emit

radiation

– Cannot be turned OFF

• Radiation emitting devices or

equipment (e.g. X-ray machines)– Machines can be turned ON and OFF

– When turned OFF, no radiation is

emitted

Sources of Ionising Radiation

• Radioactive materials – Radioactive materials continuously emit

radiation

– Cannot be turned OFF

• Radiation emitting devices or

equipment (e.g. X-ray machines)– Machines can be turned ON and OFF

– When turned OFF, no radiation is

emitted

Radioactive Materials

• unstable atoms that DECAY by emitting particles and/or electromagnetic radiation

• Release of ENERGY

• decays to form a more stable nuclide

• Results in the formation of new elements

• There are about more than 2,000 unstable or radioactive nuclides

Radioactive Materials

• The rate at which the is radiation emitted is called the activity

• Becquerel (Bq) OR Curie (Ci)

• Half-life • The TIME taken for one half

the nuclei in the sample to decay

1 Bq = 1 disintegration per second (dps)

1 Ci = 3.7 x 1010 Bq

Radioactive Materials

• The rate at which the is radiation emitted is called the activity

• Becquerel (Bq) OR Curie (Ci)

• Half-life • The TIME taken for one half

the nuclei in the sample to decay

1 Bq = 1 disintegration per second (dps)

1 Ci = 3.7 x 1010 Bq

Cs-137 ~ 30 yearsI-131 ~ 8 daysSr-90 ~ 28 yrs

Sources of Ionising Radiation

• Natural Sources

• Man-made Sources

www.ocrwm.doe.gov/.../radiation-pathways.jpg

Natural Source: Common Building Materials

Natural Sources: Food, Water, Air

Natural Sources: Your body

Man-made sources

• Nuclear reactors

• Medicine

• Food & agriculture

• Industry

• Household uses

• Nuclear weapons

• Archaeology & Geology

Man-Made Sources : Modern Health Care

Conventional

Diagnostic

X-rays

Nuclear medicine

for therapy

& diagnosis

Man-Made Sources : Modern Health Care

Fluoroscopic imaging of

body systems

Radiation therapy for

cancer treatment

Man-Made Sources: Industry

Gauges for levels in cans

& contents of bottles

Food irradiation

Man-Made Sources: Industry

Soil density &

Moisture content

analysis of roadsIndustrial radiography for

Thickness of steel &

Integrity of welds

Households & buildings

Smoke detectors

Static eliminators

Global radiation dose

natural radon

38%

natural cosmic

12%

natural external

16%

natural internal

10%

medical

12%

nuclear

12%

Global Radiation Dose

(UNSCEAR 2000)

What could happen to the body when

exposed to radiation?

What could happen to the body when

exposed to radiation?

Biological effects

• Biological effects on living cells

1. Cells experience DNA damage that are detected & repaired

2. DNA damage not repaired and causes cell death

3. Cell experiences DNA mutation and may induce cancer

Radiation Effects

Radiation Dose

� Absorbed radiation dose (energy/mass) received by the body taking into account the radiation sensitivity of specific tissues and body organs

�measure of the biological effect of a particular type of radiation on organs or tissues

� Sieverts ( Sv )

�milliSv (mSv) = 1/1000 Sv�microSv (µSv) = 1/1,000,000 Sv�nanoSn (nSv) = 1/1,000,000,000 Sv

� Absorbed radiation dose (energy/mass) received by the body taking into account the radiation sensitivity of specific tissues and body organs

�measure of the biological effect of a particular type of radiation on organs or tissues

� Sieverts ( Sv )

�milliSv (mSv) = 1/1000 Sv�microSv (µSv) = 1/1,000,000 Sv�nanoSn (nSv) = 1/1,000,000,000 Sv

Exposure Limits

Occupational

exposure to

radiation

Radiation Doses Received (mSv)

0.4 - 1.5 one chest X-ray

0.1 Background (per hr), Red Forest Chernobyl Exclusion zone

1-3 Mammogram

3 US average annual natural background

10 natural background Kerala coast, India

50 Cranial CT scan

100 small increase in cancer risk

250 - 1000 Temporary nausea, blood cell changes, sterility in males;

1000 - 3000Nausea, fatigue, vomiting, blood cell changes, loss of appetite,

sterility in males, death possible

3000 - 6000early death in 50% of those exposed, sterility and cataracts in

survivors

dose limit for workers

dose limit for Fukushima NPP workers

Radiation Doses Received (mSv)

0.4 - 1.5 one chest X-ray

0.1 Background (per hr), Red Forest Chernobyl Exclusion zone

1-3 Mammogram

3 US average annual natural background

10 natural background Kerala coast, India

50 Cranial CT scan

100 small increase in cancer risk

250 - 1000 Temporary nausea, blood cell changes, sterility in males;

1000 - 3000Nausea, fatigue, vomiting, blood cell changes, loss of appetite,

sterility in males, death possible

3000 - 6000early death in 50% of those exposed, sterility and cataracts in

survivors

dose limit for workers

dose limit for Fukushima NPP workers

Summary of Radiation Effects

Relative Risks: Loss of Life Expectancy

Cohen,B.L. Catalog of risks extended and updated, Health Physics 61/3:317-333 (1991)

Cohen,B.L. Catalog of risks extended and updated, Health Physics 61/3:317-333 (1991)

Relative Risks: Loss of Life Expectancy

www.ocrwm.doe.gov/.../radiation-pathways.jpg

Radiation exposure

HOW CAN YOU

CONTROL

RADIATION

EXPOSURE?

How to Control Exposure?

DISTANCEDISTANCE

SHIELDINGSHIELDING

TIMETIME

Time distance shielding

Minimize TIME

The less time that people are exposed to a radiation source, the lesser the absorbed dose.

Maximize DISTANCE

• the greater the distance from a

source of penetrating radiation,

the less the overall exposure

Incorporate shielding

Barriers of lead, concrete or water can stop radiation or reduce radiation intensity.

Radiation Controls

• Evacuation (maximizing distance)

• Sheltering (shielding, minimizing

inhalation)

• Restriction of food products in

affected areas (minimizing ingestion)

• Restriction in water intake in

affected areas (minimizing intake)

• Medical intervention (taking of pills)

• Radiation monitoring

Radiation Controls

• Evacuation (maximizing distance)

• Sheltering (shielding, minimizing

inhalation)

• Restriction of food products in

affected areas (minimizing ingestion)

• Restriction in water intake in

affected areas (minimizing intake)

• Medical intervention (taking of pills)

• Radiation monitoring

NOT YET NECESSARY

IN THE PHILIPPINES

AFFECTED AREAS IN JAPAN

ARE LOCALIZED

RADIATION MONITORING

IS ONGOING

Regular Bulletins at

PNRI website

www.pnri.dost.gov.ph

Questions?

That’s all..

Thank you!!!!