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Laboratory Safety

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Types of Radiation

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Particle Radiation

AlphaHe nucleus (heavy particle)+2 chargeInternal hazard only

BetaElectron-1 chargeInternal and external hazard

Neutron

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Photon Radiation

Gammas and X-rays are identical except in their origin

Gammas - produced from the nucleus of an atom

X-rays are produced outside the nucleus of an atom

Very penetrating radiationMust have shielding for protection

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Neutron shielding material depends on the energy of the neutrons

Shielding for , and

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Exposure (R) (roentgen) 조사선량 (공기)Amount of charge produced per unit mass of air from x-rays and gamma rays. Based on the quantity of electrical charges produced in air by X-ray or Gamma photons. 1R=2 billion pr

Absorbed Dose (rad) 흡수선량 (물질)Radiation Absorbed Dose is the work energy resulting from the absorption of one ROENTGEN or 6.24 E5 MevAmount of Energy deposited per unit mass of material. 1Gy (GRAY) = 100 rad.

Dose Equivalent (rem) 선량당량 (인체)Roentgen Equivalent Mammal is equal to the absorbed does in RADS multiplied by a quality factorThe absorbed dose is weighted by the radiation type and tissue susceptibility to biological damage. 1 Sv (SIEVERT) = 100 rem

Radiation Units

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Measure of

Amount ofradioactive material

Ionization in air

Absorbed energy per mass

Absorbed dose weighted by type of radiation

Radiation Units

For most types of radiation 1 R 1 rad 1 rem

Quantity

Activity

Exposure

Absorbed Dose

Dose Equivalent

Unit

curie (Ci)

roentgen (R)

rad

rem

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Radiation Units

Exposure (R) (roentgen)

Absorbed Dose (rad)

Dose Equivalent (rem)

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대상단위명, 기호

정의 SI 단위

조사선량 R 공기 1kg당 2.58 x 10-4 쿨롱의 에너

지 흡수가 있을 때의 선량. 1C/kg(= 3,876 R)

흡수선량 rad 물질 1g당 100erg의 에너지 흡수를1red로 한다.1Gy = 1J/kg = 100 rad

선량당량 rem흡수선량 (D,rad) X 선량계수(Q) X 수정계수(N)

1Sv = D(Gy) X Q X N = 100 rem

방사능 Ci 3.7 X 1010개/초의 비율로 원자핵이

붕괴될 때의 양을 1Ci 로 한다.1Bq = 2.7 X 10-11 Ci

Radiation Units

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Units of Radioactivity

Curie (Ci) = 2.22 X 1012 dpm or 3.7 X 1010 dps

Becquerel (Bq) = 1 dps

Maximum Dose/year = 5 REM or 50 mSv

Maximum Dose/year for Declared Pregnant Woman & Minors= 0.5 REM or 5 mSv

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Units of Exposure

The threshold for damage to the human body is 100 rad. It is a measurement of exposure.

1 Rad = 1 Rem (10 mSv)

1 rem = 1000 mRem

Then, 100,000 mRem = 100 Rad

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자연방사선에 의한

인체의 피폭선량은

1년간 평균 300-

500 mRem

Examples of Natural Radiation

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담배를 하루에 1갑씩 1년간 계속 피운 사람의 발암 확률은,

7,000~28,000 mrem의 방사선 피폭을 받은 사람의 발암 확률과 같다.

Smoking

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Life Expectancy Lost

Health Risk Est. Life Lost

Smoking 20 cigs a day

Overweight (15%)

Alcohol (US Average)

All Accidents

Occupational dose (1 Rem/yr)

6 years

2 years

1 year

207 days

51 days

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RADIATION PROTECTION PRINCIPLES

The body may be irradiated in two general ways:

Externally from radioactive material or radiation sources,

External doses can be the result of exposure to gamma, X-ray, or high energy beta emitters. Low energy beta and alpha emitters lack the energy needed to penetrate the outer layer of skin and subsequently present less of an external hazard; they are of more concern when ingested.

Internally from radioactive material deposited in the body.

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The external dose an individual receives depends on the following factors: exposure, time, distance, and shielding.

Exposure. The "strength" (activity, mR/hr, etc.) of the radiation source. By reducing the amount of radioactive material used, dose can be reduced.Time. The total dose received from an external source also depends on the amount of time actually exposed to the source. Therefore, any time that is spent near a source should be minimized and used effectively.

RADIATION PROTECTION PRINCIPLES

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Distance. By increasing the distance between the source of exposure and an individual, the dose received can be significantly reduced. When an individual doubles his/her distance from a source, the dose will usually be reduced by approximately one-fourth.Shielding. When radiation sources are being used, absorbing material or shields can be incorporated to reduce exposure levels. The specific shielding material and thickness is dependent on the amount and type of radiation involved.

RADIATION PROTECTION PRINCIPLES

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Internal exposure results from the absorption, ingestion or inhalation of radioactive material. This material can be incorporated in the body in several ways:

by breathing radioactive gases, vapors or dustby consuming radioactive material transferred from contaminated hands, tobacco products, food or drinkby entering through a woundby absorption through the skin

RADIATION PROTECTION PRINCIPLES

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The fundamental objectives of radiation protection measures are:

to limit entry of radionuclides into the human body (via ingestion, inhalation, absorption, or through open wounds) to quantities as low as reasonably achievable (ALARA) and always within the established limits.to limit exposure to external radiation to levels that the established dose limits are below and as low as reasonably achievable.

RADIATION PROTECTION PRINCIPLES

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RI Lab Safety Rules

Eating, drinking, smoking, and the application of cosmetics are prohibited in a room where radioactive materials are used or stored. Protective gloves shall be worn when handling contaminated or potentially contaminated items. Persons with open wounds should be particularly careful when working with radioactive materials (the wound should be properly covered). Hands should be washed thoroughly after handling radioactive materials, especially before eating. Food items shall not be stored in areas or equipment designated for radioactive materials. Personnel monitoring badges shall be worn in restricted areas, as applicable.

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Conduct radiation meter surveys after each use and wipe test surveys frequently (document at least monthly). When measurements are abnormal, find the cause and correct. When using volatile radionuclides (e.g. iodine) or heating radioactive solutions, always perform work in a properly operating fume hood. Label all containers of radioactive materials, including radionuclide, amount and date.Utilize shielding when necessary to maintain radiation levels as low as reasonably achievable (ALARA). Store radioactive material in locked cabinets/refrigerators or keep the laboratory door locked when lab personnel are not present.

RI Lab Safety Rules

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Biological Effects

Many groups exposed to ionizing radiation at high levels resulted in adverse effects.

Somatic effects

Prompt - skin burns and cataracts

Delayed - cancer

Genetic effects

Teratogenetic effects

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Cancer

Radiation can damage cells through two methods;

Production of free radicals

Direct damage to the DNA.

Risk factor for radiation dose:4% increase in risk of dying of cancer for every 100 rem of dose.

Normal cancer risk is 10%.

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Radiation Doses and Dose Limits

Flight from Los Angeles to London 5 mrem

Annual public dose limit 100 mrem

Annual natural background 300 mrem

Fetal dose limit 500 mrem

Barium enema 870 mrem

Annual radiation worker dose limit 5,000 mrem

Heart catheterization (skin dose) 26,000 mrem

Life saving actions guidance (NCRP-116) 50,000 mrem

Mild acute radiation syndrome 200,000 mrem

LD50/60 for humans (bone marrow dose) 350,000 mremRadiation therapy (localized & fractionated) 6,000,000 mrem

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Acute Exposure

Large Doses Received in a Short Time Period

Accidents

Nuclear War

Cancer Therapy

Short Term Effects (Acute Radiation Syndrome 150 to 350 rad Whole Body)

Anorexia, Nausea, Erythema, Fatigue, Vomiting, Hemorrhage, Diarrhea, Mortality

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Occurs only in patients who have received very high radiation doses (greater than approximately 100 rem) to most of the body

Dose ~ 15 rem

No symptoms, possible chromosomal aberrations

Dose ~ 50 rem

No symptoms, minor decreases in white cells and platelets

Acute Radiation Syndrome

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Dose ~ 100 rem~10% exhibit nausea and vomiting within 48 hr mildly depressed blood counts

Dose ~ 350 rem~90% exhibit nausea/vomiting within 12 hr, 10% exhibit diarrhea within 8 hrsevere bone marrow depression ~50% mortality without supportive care

Dose ~ 500 rem~50% mortality with supportive care

Dose ~ 1000 rem90-100% mortality despite supportive care

Acute Radiation Syndrome

Hematopoietic Component

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Dose > 1000 rem - damage to GI systemsevere nausea, vomiting and diarrhea (within minutes)short latent period (days to hours)usually fatal in weeks to days

Dose > 3,000 rem - damage to CNSvomiting, diarrhea, confusion, severe hypotension within minutescollapse of cardiovascular and CNSfatal within 24 to 72 hours

Gastrointestinal and CNS Components

Acute Radiation Syndrome

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Effects of Acute Whole Body Exposure on Man

AbsorbedDose (Rads) Effect

10,0001,200

60045010050255

Death in a few hoursDeath within daysDeath within weeksLD 50/30Probable RecoveryNo observable effectBlood changes definite1st Blood change obs

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Chronic Health Effects from Radiation

Radiation is a weak carcinogen at low dosesNo unique effects (type, latency, pathology)Natural incidence of cancer ~ 40%; mortality ~ 25%Risk of fatal cancer is estimated as ~ 5% per 100 rem A dose of 5 rem increases the risk of fatal cancer by ~ 0.25%A dose of 25 rem increases the risk of fatal cancer by ~ 1.25%

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Variations in Sensitivity

Wide variation in the radio sensitivity of various species

Plants/microorganisms vs. mammals

Wide variation among cell types Cells which divide are more sensitive

Non-differentiated cells are more sensitive

Highly differentiated cells (like nerve cells) are less sensitive

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동 물 X선 또는 선에 대한반치사 (LD50) 선량

양당 나 귀돼 지염 소개

사 람모 르 모 트원 숭 이새 앙 쥐토 끼흰 쥐

2.05 (Gy)2.30 ~ 3.101.90 ~ 3.10

2.402.40 ~ 3.20

~ 3.003.80 ~ 4.905.20 ~ 5.505.20 ~ 6.706.80 ~ 9.108.00 ~ 8.20

Variations in Sensitivity

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Effects on the Fetus

The fetus consists of rapidly dividing cells

Dividing cells are more sensitive to radiation effects than non-dividing cells

Effects of low level radiation are difficult to measure

A lower dose limit is used for the fetus

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Genetic Effects

It is possible to damage the hereditary material in a cell nucleus by external influences like Ionizing radiation, chemicals, etc. Effects that occur as a result of exposure to a hazard while in-utero are called teratogeniceffectsTeratogenic effects are thought to be more severe during weeks 8~17 of pregnancy -the period of formation of the body’s organsA higher incidence of mental retardation was found among children irradiated in-utero during the bombings of Hiroshima and Nagasaki