C3: Biological Effects of Ionizing Radiation

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Questions and Answers

When lead aprons are employed, personnel monitoring devices should be worn:

Inside or outside the apron level of the waist (correct)

Outside the apron level of the waist

Inside the apron level of the neck

Outside the apron level of the neck

Which of the following is the most sensitive to ionizing radiation?

Adult

Fetus (correct)

Child

Adolescent

The degree of radiation injury on an individual depends on the followings EXCEPT…

Type of radiation

Dose and dose rate

Part of the body that is exposed

Blood type (correct)

The system of the body which is most sensitive to radiation exposure.

Reproductive Signup and view all the answers

Below are Acute Radiation Syndrome (ARS) EXCEPT.

Down Syndrome Signup and view all the answers

What is the process of ionization?

Converting atoms or molecules into ions by adding charged particles Signup and view all the answers

Which type of radiation is capable of displacing electrons?

Ionizing radiation Signup and view all the answers

What body component is damaged by radiation, resulting in possible mutations or cell death?

DNA Signup and view all the answers

What can modify the effects of ionizing radiation?

The type, energy, and dosage of the radiation Signup and view all the answers

What are the effects of partial body irradiation compared to uniform irradiation of the whole body for the same dose?

Milder effects Signup and view all the answers

How does dose rate affect the severity of radiation damage?

Decreases severity Signup and view all the answers

What is the characteristic of stochastic effects (e.g., cancer) in relation to radiation dosage?

Severity is proportional to dose Signup and view all the answers

What are the symptoms of Gastrointestinal (GI) Syndrome?

Melaena, nausea, and dehydration Signup and view all the answers

Which type of radiation interaction with water leads to the formation of very reactive free radicals?

Indirect Action Signup and view all the answers

What is the prognosis for Central Nervous System (CNS) Syndrome?

100% death within 1-5 days Signup and view all the answers

What is the recommended maximum radiation exposure for fertile women at the workplace, according to NCRP?

0.03 Sv per year Signup and view all the answers

What is the risk faced by children to cancer due to radiation exposure, per Sv?

2.8x10-2 per Sv Signup and view all the answers

Study Notes

Central Nervous System (CNS) Syndrome: occurs with dose exposure greater than 15 Gy, leads to unconsciousness and death due to damages to central nervous system and heart muscle within hours to several days, symptoms include convulsion, motor incoordination, coma, and symptoms of gastrointestinal and bowel syndromes, prognosis is 100% death within 1-5 days
Radiation Injury Mechanism: begins at the physico-chemical level in cells, interaction of radiation with water is the main basis for biological effects, two types of radiation interactions: direct and indirect
Direct Action: ionizing radiation causes excitation, ionization, and breakage of molecules such as DNA helix, produces when primary interaction of radiation is with target atoms in the cell, dominates with high LET radiation (alpha, neutron)
Indirect Action: interaction of radiation with water leads to the formation of very reactive free radicals which attack target molecules in cells, such as DNA, dominates with low LET radiation (x-ray, gamma)
Effects on DNA: low LET radiation alters DNA structure in human chromosome leading to mutations, high LET radiation causes extensive chromosome damage and cell death
Risk of Radiation to Pregnant Women: exposure to zygote or embryo results in death, mental retardation, physical disability, reduction of IQ, or disturbance of growth, risk faced by children to cancer is 2.8x10-2 per Sv
Job Exposure of Fertile Women: NCRP suggests fertile women not to receive radiation at work place exceeding 0.03 Sv (30mSv) per year for the safety of fetus, "10 days rule" allows radiology procedures on the first 10 days after onset of menses when probability of pregnancy is minimum
Effects of X-rays on Pregnancy: exposure to 200 R of IR leads to abnormalities in experimental animals and humans
Radiation Effects: chronic exposure leads to cancer, sterility, and cataracts; acute exposure causes radiation sickness and erythema; late effects include hereditary effects and stochastic effects.

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Description

Test your knowledge on radiation dosage and dose rate with this quiz. Learn about the effects of different levels of radiation exposure and how dose rate can impact the severity of health effects.