Radiation MeasurementRadiation Measurement

Terminology:

– Exposure rate = amount radiation possible to receive per unit time.

– Dose = total amount of radiation received.

2.  Berdasarkan dosis radiasia..E fek Stokastik Efek terjadi sebagai akibat paparan radiasi dengan dosis

yang menyebabkan terjadinya perubahan pada sel. Tidak mengenal dosis ambang  Timbul setelah melalui masa tenang yang lama  &

Keparahannya tidak bergantung pada dosis radiasi  Tidak ada penyembuhan spontan  Efek ini meliputi : kanker, leukemia (efek somatik), dan

penyakit keturunan (efek genetik).

b. Efek Deterministik (non-stokastik) adalah efek yang kualitas keparahannya bervariasi menurut dosis dan hanya timbul bila dosis ambang dilampaui.

Mempunyai dosis ambang .timbul beberapa saat setelah radiasi 

Adanya penyembuhan spontan (tergantung keparahan) & Tingkat keparahan tergantung terhadap dosis radiasi 

Efek ini meliputi : luka bakar, sterilitas / kemandulan, katarak (efek somatik)

Radiation and Radioactivity: Radiation and Radioactivity: Units and QuantitiesUnits and Quantities

Department of HealthBureau of Radiation Control

Introduction Introduction

Quantities (mass, volume, time, etc.) vs. Units (grams, gallons, hours)

Units of exposure, radioactivity, and energy associated with ionizing radioactivity

As hours and minutes are to time ...

ObjectivesObjectives

Define – ROENTGEN, RAD, REM, CURIE, GRAY,

SIEVERT, BECQUEREL.– SI units vs. Standard English units

Discuss the use and conversion of unit prefixes

Transform units using “unit analysis”

Background Background

Early risk associated with use of ionizing radiation

skin erythema dose - 25yrs1928 - ROENTGEN introduced by ICRP

RoentgenRoentgen

RoentgenRoentgen

Pronounced rent’gen with a hard “g”Limitations

– only applies to photons– only applies in air– only applies to energies less than 3 MeV

Named after Wilhelm C. Roentgen (thus the abbr... is capital “R”)

radrad

radrad1 rad = 1 Roentgen

remrem

remrem

The unit of dose equivalent for any type of ionizing radiation absorbed by body tissue in terms of estimated biological effect - Unit of dose equivalent

Dose in health record is in units of rem1 rem = 1 Roentgen

Roentgen Equivalent Man

Quality Factor (Q)Quality Factor (Q)

The specific value that accounts for the ability of different types of ionizing radiation to cause varying degrees of biological damage– X-rays, gamma rays, & beta particles 1– Neutrons & High energy protons 10– Alpha Particles 20

Curie (Ci)Curie (Ci)

Radiation hazard does not solely depend on the activity. It also depends on the type of decay (alpha, beta, photon, etc.)

Named in honor of Pierre Curie

SI Radiation Protection UnitsSI Radiation Protection Units

Becquerel (Bq) for Curie– 1 Ci = 3.7 x 1010 Bq

Gray (Gy) for rad– 1 Gy = 100 rad

Sievert (Sv) for rem– 1 Sv = 100 rem

Unit AnalysisUnit Analysis

BASE UNIT CONVERSION TABLE

Unit Unit Conversion1 Bq 2.7 x 10-11 Ci1 Ci 3.7 x 1010 Bq

1 Bq 1 dis/sec1 dis/sec 2.7 x 10-11 Ci1 Ci 3.7 x 1010 dis/sec

Unit Analysis (Con’t.)Unit Analysis (Con’t.)BASE UNIT CONVERSION TABLE

Unit Unit Conversion

1 rem 0.01 Sv1 Sv 100 rem1 rad 0.01 Gy1 Gy 100 rad1 R 2.58 x 10-4 C/kg1 meter 3.28 ft (39.37in)

SummarySummary

Radiation Protection unit definitions (including SI units)

Unit PrefixesUnit conversions

New Terms New Terms sort ofsort of

International Units have replaced the RAD and REM

GRAY (Gy) = 100 RADSIEVERT (Sv) = 100 REM

Same Quality Factors apply to the Sv

Units of RadioactivityUnits of Radioactivity

Curie (Ci) = 2.22 E12 dpm or 3.7E10 dpsBecquerel (Bq) = 1 dpsMaximum Dose/year = 5 REM or 50 mSvMaximum Dose/year for Declared Pregnant

Woman & Minors= 0.5 REM or 5 mSv

          

Annual Dose LimitsAnnual Dose LimitsExternal/Internal Exposure Limits for Occupationally Exposed Individuals

  Adult ($18 yrs) Minor (< 18 yrs)

Whole body* 5000 mrem/yr 500 mrem/yr

Lens of eye 15000 mrem/yr

1500 mrem/yr

Extremities 50000 mrem/yr

5000 mrem/yr

Skin 50000 mrem/yr

5000 mrem/yr

Organ 50000 mrem/yr

5000 mrem/yr

*Effective dose equivalent

Dose Response RelationshipsDose Response Relationships

0-150 rem—No or minimal symptoms150-400 rem—Moderate to severe illness400-800 rem—Severe illness deaths start

above 500 remAbove 800 rem—Fatal

***Acute whole body doses

Your Annual ExposureYour Annual ExposureActivity Typical DoseSmoking 280 millirem/year

Radioactive materials use  in a UM lab <10 millirem/year

Dental x-ray 10 millirem per x-ray

Chest x-ray  8 millirem per x-ray

Drinking water  5 millirem/yearCross country round trip by air  5 millirem per trip 

Coal Burning power plant 0.165 millirem/year 

Estimated Exposure To The Estimated Exposure To The National PopulationNational Population

Between 320 – 360 mr/yr

Another Look at SourcesAnother Look at Sources

Some Exposure LimitsSome Exposure Limits 2 mr/hr Dose rate to public / Federal 500 mr Emergency responder limit / State/BRC 5 r/yr Occupational /Federal 5 r/hr Turn back value / State/BRC 10 r Property / Federal 25 r Life saving / Federal >25r Volunteers only / Federal

Ref - 10CFR PART 20, EPA 400, FL-SOP

Security Security

All Radioactive Materials must be secured or under direct supervision at all times

There MUST be someone in the room at all times OR the door must be locked.

Spill ResponseSpill Response

On Skin—flush completelyOn Clothing—removeIf Injury—administer first aidRadioactive Gas Release—vacate area,

shut off fans, post warningMonitor all persons and define the area of

contamination

ALARAALARA

As Low As Reasonably Achievable—means making every reasonable effort to maintain exposures to radiation as far below the dose limits as is practicable consistent with the purpose for which the licensed activity is undertaken, taking into account the state of technology, the economics of improvements in relation to the state of technology, the economics of improvements in relation to benefits to the public health and safety, and other societal and socioeconomic considerations, and in relation to utilization of nuclear energy and licensed materials in the public interest.