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The sievert (Sv) is a fundamental SI unit primarily employed to quantify the physical quantity of energy deposited per unit mass of material.
Answer: False
This statement is incorrect. While the sievert is an SI unit, it measures the stochastic health risk associated with ionizing radiation (equivalent dose and effective dose), not the physical quantity of energy deposited per unit mass, which is measured by the gray (Gy).
The International Committee for Weights and Measures (CIPM) defines the sievert as the unit for dose equivalent (H), calculated as the product of absorbed dose (D) and a dimensionless quality factor (Q).
Answer: True
This statement is accurate. The CIPM defines the sievert in relation to dose equivalent (H), where H is derived from the absorbed dose (D) multiplied by a quality factor (Q) that accounts for the biological effectiveness of the radiation type.
The ICRP defines the sievert as the special name for the SI unit of equivalent dose and effective dose, with the unit being joule per kilogram.
Answer: True
This statement is correct. The sievert (Sv) is indeed the special name for the SI unit of equivalent dose and effective dose, and it is dimensionally equivalent to joule per kilogram (J/kg), reflecting its basis in absorbed dose but incorporating biological risk factors.
Milli (mSv) and micro (µSv) are commonly used SI prefixes with the sievert unit for practical dose measurements and limits.
Answer: True
This statement is accurate. Millisieverts (mSv) and microsieverts (µSv) are frequently employed prefixes for the sievert, facilitating the expression of radiation doses and regulatory limits in practical, manageable magnitudes.
The sievert directly relates to the probability of stochastic health effects, such as cancer induction.
Answer: True
This statement is correct. The primary purpose of the sievert unit is to quantify the potential for stochastic health effects, such as cancer and hereditary effects, by relating dose to the probability of their occurrence.
What does the sievert (Sv) unit primarily measure?
Answer: The stochastic health risk associated with ionizing radiation.
The sievert (Sv) is the SI unit specifically designed to quantify the stochastic health risk, such as the probability of cancer induction and genetic effects, associated with exposure to ionizing radiation. It accounts for the biological effectiveness of different radiation types and the sensitivity of exposed tissues.
What is the relationship between the sievert (Sv) and the joule per kilogram (J/kg)?
Answer: 1 Sv is equal to 1 J/kg, but adjusted for biological risk.
Dimensionally, 1 Sv is equivalent to 1 J/kg, the same as the gray (Gy). However, the sievert specifically incorporates weighting factors (W_R and W_T) to account for the biological effectiveness of different radiation types and tissue sensitivities, thereby representing biological risk rather than just energy deposition.
The unit 'sievert' is named in honor of Rolf Maximilian Sievert, a Swedish physicist recognized for his work in radiation measurement and biological effects.
Answer: True
This statement is accurate. The sievert unit was established to honor Rolf Maximilian Sievert, a pivotal figure in radiation physics whose research significantly advanced the understanding of radiation dosimetry and its biological implications.
One sievert is equivalent to 1000 rem, making the sievert a smaller unit than the older rem.
Answer: False
This statement is incorrect. The correct conversion is 1 sievert (Sv) = 100 rem. Therefore, the sievert is a larger unit than the rem.
The gray (Gy) and the sievert (Sv) are interchangeable SI units measuring the same physical quantity in radiation dosimetry.
Answer: False
This statement is incorrect. The gray (Gy) measures absorbed dose (energy deposited per unit mass), while the sievert (Sv) measures equivalent dose and effective dose, which account for the biological risk. They are related but not interchangeable.
The sievert unit originated from the SI unit 'gray' and was developed to measure absorbed dose.
Answer: False
This statement is incorrect. The sievert unit is derived from the older CGS unit 'rem' and is used for equivalent dose and effective dose, which quantify biological risk. The gray (Gy) is the SI unit for absorbed dose.
The sievert was adopted by the International Committee for Weights and Measures (CIPM) in 1975.
Answer: False
This statement is incorrect. The sievert was officially adopted by the CIPM in 1980, following the adoption of the gray in 1975.
The SI equivalent of the older unit 'rad' is the sievert (Sv).
Answer: False
This statement is incorrect. The SI equivalent of the older unit 'rad' (a unit of absorbed dose) is the gray (Gy), where 1 Gy = 100 rad. The sievert (Sv) is the SI equivalent of the 'rem' (a unit of dose equivalent).
The SI equivalent of the older unit 'rem' is 0.01 sievert (Sv).
Answer: True
This statement is accurate. The relationship between the older unit 'rem' and the SI unit 'sievert' is 1 rem = 0.01 Sv.
Who is the sievert unit named after?
Answer: Rolf Maximilian Sievert
The sievert unit is named in honor of Rolf Maximilian Sievert, a Swedish physicist whose extensive research on radiation measurement and biological effects was foundational to the field of radiation protection.
How is the sievert (Sv) related to the older unit, the rem?
Answer: 1 Sv = 100 rem
The sievert is the SI unit equivalent to the older CGS unit, the rem. The conversion factor is 1 sievert equals 100 rem, indicating that the sievert is a larger unit.
What is the primary distinction between the SI units gray (Gy) and sievert (Sv)?
Answer: Gy measures absorbed dose, while Sv measures biological effect/risk.
The gray (Gy) quantifies the physical amount of energy absorbed per unit mass of material (absorbed dose). The sievert (Sv) quantifies the potential biological harm (equivalent dose and effective dose) resulting from that absorbed energy, considering radiation type and tissue sensitivity.
The sievert unit was adopted by the CIPM in which year?
Answer: 1980
The International Committee for Weights and Measures (CIPM) officially adopted the sievert as a unit for dose equivalent in 1980.
What is the SI equivalent of the older unit 'rem'?
Answer: 0.01 Sv
The SI unit equivalent to the older unit 'rem' (roentgen equivalent man) is the sievert (Sv), with the conversion factor being 1 rem = 0.01 Sv.
Which unit is the SI equivalent of the older unit 'rad'?
Answer: Gray (Gy)
The SI unit equivalent to the older unit 'rad' (a unit of absorbed dose) is the gray (Gy). The relationship is 1 Gy = 100 rad.
To calculate the value in sieverts, the absorbed dose in grays is directly multiplied by the radiation type and tissue sensitivity factors.
Answer: False
This statement is inaccurate. While absorbed dose in grays is a foundational quantity, the conversion to sieverts (for equivalent or effective dose) involves multiplying by specific radiation weighting factors (W_R) and, for effective dose, tissue weighting factors (W_T), rather than generic 'tissue sensitivity factors' applied directly to absorbed dose.
The radiation type weighting factor (W_R) is used to adjust the absorbed dose to account for the varying biological effectiveness of different radiation types.
Answer: True
This statement is accurate. The radiation weighting factor (W_R) is a dimensionless multiplier applied to the absorbed dose to convert it into equivalent dose, thereby accounting for the differing biological impact of various radiation types (e.g., alpha particles vs. gamma rays) for the same absorbed energy.
According to ICRP report 103, X-rays and alpha particles have the same radiation weighting factor (W_R).
Answer: False
This statement is incorrect. According to ICRP report 103, X-rays have a radiation weighting factor (W_R) of 1, whereas alpha particles have a W_R of 20, reflecting their significantly higher biological effectiveness.
The tissue weighting factor (W_T) is applied to account for the varying sensitivity of different tissues to radiation when calculating effective dose.
Answer: True
This statement is accurate. Tissue weighting factors (W_T) are crucial components in calculating effective dose, as they represent the relative contribution of each organ or tissue to the total stochastic health risk from radiation exposure, reflecting their differing sensitivities.
The formula for equivalent dose (H_T) to a tissue T involves summing the absorbed doses from each radiation type multiplied by the respective tissue weighting factor (W_T).
Answer: False
This statement is incorrect. The formula for equivalent dose (H_T) to a tissue T involves summing the absorbed doses from each radiation type (D_T,R) multiplied by the respective radiation weighting factor (W_R): H_T = Σ(W_R * D_T,R). Tissue weighting factors (W_T) are applied subsequently to calculate the effective dose (E).
The statement '1 Gy of alpha particles equals 20 Sv' implies that alpha particles deposit the same energy as X-rays but have a significantly lower biological risk.
Answer: False
This statement is incorrect. The relationship '1 Gy of alpha particles equals 20 Sv' signifies that alpha particles, while depositing the same amount of energy per unit mass (1 Gy), possess a significantly *higher* biological risk compared to X-rays, as accounted for by the radiation weighting factor (W_R = 20 for alpha particles).
Tissue weighting factors (W_T) have remained constant across different ICRP publications since ICRP 26.
Answer: False
This statement is incorrect. Tissue weighting factors (W_T) have undergone revisions in successive ICRP publications (e.g., ICRP 26, 60, and 103) to reflect evolving scientific understanding of tissue radiosensitivity.
What is the purpose of the radiation weighting factor (W_R) in dosimetry?
Answer: To account for the varying biological effectiveness of different types of radiation.
The radiation weighting factor (W_R) is employed to adjust the absorbed dose (measured in grays) to account for the fact that different types of radiation cause differing degrees of biological damage for the same amount of deposited energy. This allows for the calculation of equivalent dose in sieverts.
According to ICRP report 103, what is the radiation weighting factor (W_R) for alpha particles?
Answer: 20
In ICRP report 103, alpha particles are assigned a radiation weighting factor (W_R) of 20, reflecting their high linear energy transfer (LET) and consequently greater biological effectiveness compared to sparsely ionizing radiation like X-rays or gamma rays.
What role do tissue weighting factors (W_T) play in radiation dosimetry?
Answer: They account for the varying sensitivity of different tissues to radiation when calculating effective dose.
Tissue weighting factors (W_T) are applied to the equivalent dose received by individual organs or tissues. They represent the relative contribution of that tissue to the overall stochastic health risk, reflecting the differing sensitivities of various tissues to radiation-induced cancer.
What is the primary reason for using weighting factors (W_R and W_T) when calculating effective dose?
Answer: To account for the different biological risks associated with different radiation types and tissues.
Weighting factors (W_R for radiation type and W_T for tissue sensitivity) are essential for calculating effective dose because they integrate the physical dose with biological considerations, allowing for a unified measure of overall stochastic health risk across different exposure scenarios.
How do tissue weighting factors (W_T) differ between ICRP publications 26 and 103?
Answer: Both B and C are correct.
Tissue weighting factors have been revised across ICRP publications. Notably, the W_T for gonads decreased from 0.25 in ICRP 26 to 0.08 in ICRP 103, while the W_T for the colon increased from an unspecified value in ICRP 26 to 0.12 in ICRP 103, reflecting updated risk assessments.
The ICRU is responsible for defining protection quantities based on biological sensitivity, while the ICRP defines operational quantities based on metrology.
Answer: False
This statement reverses the roles. The International Commission on Radiological Protection (ICRP) is primarily responsible for defining protection quantities, which are based on biological sensitivity and dose uptake models. The International Commission on Radiation Units and Measurements (ICRU) is primarily responsible for defining operational quantities, which are based on metrology and practical measurement.
The ICRP recommends an annual occupational exposure limit of 50 mSv (0.05 Sv) and a five-year average limit of 100 mSv (0.1 Sv).
Answer: True
This statement accurately reflects the recommendations of the International Commission on Radiological Protection (ICRP) for occupational exposure limits.
The ICRP's recommended annual dose limit for the public is 10 mSv (0.01 Sv), excluding medical and occupational doses.
Answer: False
This statement is incorrect. The ICRP's recommended annual effective dose limit for members of the public is 1 mSv (0.001 Sv), excluding medical and occupational exposures.
The US Nuclear Regulatory Commission (NRC) sets an annual occupational dose limit of 500 mSv (0.5 Sv) for total effective dose equivalent.
Answer: False
This statement is incorrect. The US Nuclear Regulatory Commission (NRC) sets the annual occupational dose limit for total effective dose equivalent at 50 mSv (0.05 Sv), consistent with ICRP recommendations.
According to the NRC, a high radiation area in a nuclear power plant has a dose rate of 10 mSv/h.
Answer: False
This statement is incorrect. According to the US NRC, a high radiation area is defined as a location where the dose rate exceeds 1 mSv/h (millisievert per hour) at 30 centimeters from the source or from any point on the boundary of the area.
Which organization is primarily responsible for defining protection quantities based on biological sensitivity and dose uptake models?
Answer: ICRP (International Commission on Radiological Protection)
The International Commission on Radiological Protection (ICRP) is the principal international body responsible for developing recommendations on radiation protection, including the definition of protection quantities that are based on biological sensitivity and dose uptake models.
What is the ICRP's recommended annual dose limit for occupational exposure?
Answer: 50 mSv
The International Commission on Radiological Protection (ICRP) recommends an annual effective dose limit of 50 mSv (0.05 Sv) for occupational exposure.
What is the ICRP's recommended average annual effective dose limit for members of the public?
Answer: 1 mSv
The ICRP recommends an average annual effective dose limit of 1 mSv (0.001 Sv) for members of the public, excluding doses from medical procedures and natural background radiation.
The US Nuclear Regulatory Commission (NRC) sets an annual occupational dose limit of 50 mSv. What is this limit for?
Answer: Total effective dose equivalent
The US NRC's annual occupational dose limit of 50 mSv applies to the total effective dose equivalent (TEDE), which is a measure intended to account for stochastic health risks from both external and internal radiation exposure.
What is the approximate dose rate in a high radiation area within a nuclear power plant, according to NRC definition?
Answer: 1 mSv per hour
According to the US Nuclear Regulatory Commission (NRC), a high radiation area is defined as a location where the dose rate exceeds 1 mSv per hour at 30 centimeters from the source or boundary, necessitating specific safety controls.
The sievert is exclusively used for measuring equivalent dose from external radiation sources and does not apply to internal irradiation.
Answer: False
This assertion is incorrect. The sievert is utilized for both external radiation dose quantities (such as equivalent dose and effective dose) and internal radiation dose quantities (such as committed dose, which assesses risk from inhaled or ingested radionuclides).
Operational quantities in radiation dosimetry are primarily used for defining theoretical protection limits based on biological models.
Answer: False
This statement is incorrect. Operational quantities are designed for practical, real-world measurements using instruments to estimate or provide an upper bound for protection quantities, thereby facilitating radiation monitoring and dose control, rather than defining theoretical limits.
Equivalent dose and dose equivalent are distinct concepts, with 'equivalent dose' being a protection quantity defined by the ICRP and 'dose equivalent' often associated with simpler calculations for operational quantities.
Answer: True
This statement accurately distinguishes between the terms. 'Equivalent dose' is a protection quantity defined by the ICRP, incorporating complex biological models. 'Dose equivalent' is an older term often linked to operational quantities, typically calculated using simpler quality factors (Q) based on radiation type.
Protection quantities in radiation dosimetry are calculated models used to set exposure limits and predict stochastic health effects.
Answer: True
This statement is correct. Protection quantities, such as effective dose, are derived from complex models designed to estimate the potential for stochastic health effects (like cancer) and serve as the basis for establishing regulatory dose limits.
Deterministic effects of radiation, like acute tissue damage, are typically measured in sieverts (Sv) because they are stochastic in nature.
Answer: False
This statement is incorrect. Deterministic effects, such as acute tissue damage, are characterized by a threshold dose and occur with certainty above that threshold. They are typically measured using the gray (Gy), which quantifies absorbed dose, rather than the sievert (Sv), which is used for stochastic effects that occur probabilistically.
Ambient dose equivalent (H*(10)) is used for monitoring low-penetrating radiation like alpha particles at a depth of 0.07 mm.
Answer: False
This statement is incorrect. Ambient dose equivalent (H*(10)) is primarily used for monitoring penetrating radiation (e.g., gamma rays, neutrons) and is defined at a depth of 10 mm in the ICRU sphere. The quantity used for low-penetrating radiation at a depth of 0.07 mm is directional dose equivalent (H'(0.07)).
Personal dose equivalent (H_p(10)) is typically measured by a personal dosimeter worn by an individual to assess dose to tissues beneath the surface.
Answer: True
This statement is accurate. Personal dose equivalent (H_p(10)) is a key operational quantity used for individual monitoring, representing the dose equivalent at a depth of 10 mm in the tissue equivalent material of the personal dosimeter, approximating dose to underlying tissues.
Committed dose refers to the dose received from external radiation sources over a short period.
Answer: False
This statement is incorrect. Committed dose specifically refers to the dose resulting from the intake of radionuclides into the body (internal exposure) over a defined period, typically 50 years for adults, not from external sources.
The ICRU sphere phantom is a theoretical model used to relate operational quantities to incident radiation fields by simulating body scattering and attenuation properties.
Answer: True
This statement is accurate. The ICRU sphere phantom serves as a standardized theoretical model that approximates the scattering and attenuation characteristics of the human body, enabling the relationship between measured operational quantities and the incident radiation field to be established.
Which of the following radiation dose quantities is measured in sieverts (Sv)?
Answer: Committed Dose
Committed dose, which quantifies the cumulative dose from internally deposited radionuclides over a specified time period, is measured in sieverts (Sv). Absorbed dose is measured in grays (Gy), and exposure is measured in coulombs per kilogram (C/kg).
Why are deterministic effects of radiation typically measured in grays (Gy)?
Answer: Because they are directly related to the amount of energy absorbed and have a threshold.
Deterministic effects, such as tissue damage, are generally considered to have a threshold dose and their severity increases with dose. They are directly related to the physical energy deposited, hence the unit of absorbed dose, the gray (Gy), is typically used for their assessment.
Ambient dose equivalent (H*(10)) is a practical measurement used for monitoring what type of radiation?
Answer: Penetrating radiation, such as gamma rays.
Ambient dose equivalent (H*(10)) is an operational quantity designed for monitoring penetrating radiation fields, such as those from gamma rays and neutrons. It estimates the dose equivalent at a depth of 10 mm in the ICRU sphere, providing a measure relevant for whole-body exposure.
What does 'committed dose' specifically refer to?
Answer: The total dose commitment over time from inhaled or ingested radionuclides.
Committed dose quantifies the total dose equivalent expected to be received by an individual over a specified period (typically 50 years for adults) following the intake of radioactive material into the body (internal exposure).
The ICRU sphere phantom is a theoretical model used to approximate which properties of the human body?
Answer: Scattering and attenuation of radiation.
The ICRU sphere phantom, a standardized 30 cm diameter sphere of tissue-equivalent material, is utilized to approximate the radiation scattering and attenuation characteristics of the human body, thereby facilitating the relationship between operational dose quantities and radiation fields.
Which of the following is NOT a protection quantity defined by the ICRP?
Answer: Ambient Dose Equivalent
Effective Dose, Equivalent Dose, and Committed Effective Dose are all protection quantities defined by the ICRP. Ambient Dose Equivalent (H*(10)) is an operational quantity, defined by the ICRU, used for practical monitoring.
What is the purpose of 'operational quantities' like ambient dose equivalent (H*(10))?
Answer: To provide practical measurements for radiation monitoring and dose control using instruments.
Operational quantities, such as ambient dose equivalent, are designed for practical use with radiation monitoring instruments. They provide a means to estimate or bound protection quantities in real-world radiation fields, facilitating compliance with regulations and effective dose management.
What is the main purpose of calculating 'committed effective dose (E(t))'?
Answer: To assess the total stochastic health risk over time from internal radiation exposure.
Committed effective dose (E(t)) is calculated to estimate the total risk of stochastic health effects (primarily cancer) arising from the intake of radioactive materials into the body, considering the dose accumulated over a long period (typically 50 years).
The slab phantom is used in dosimetry primarily for:
Answer: Calibrating whole-body dosimeters by simulating torso back-scattering and absorption.
The slab phantom, representing the human torso, is employed in radiation dosimetry for the calibration of whole-body dosimeters. It accurately simulates the back-scattering and absorption effects characteristic of the human body, ensuring more reliable measurements.
According to the ICRP, one sievert of radiation exposure corresponds to an estimated 5.5% probability of developing fatal cancer, based on the linear no-threshold model.
Answer: True
This statement accurately reflects the consensus estimate provided by the International Commission on Radiological Protection (ICRP), which posits a 5.5% increase in the probability of fatal cancer per sievert of effective dose, predicated on the linear no-threshold (LNT) model.
The linear no-threshold (LNT) model posits that radiation risk is zero below a certain dose threshold.
Answer: False
This statement is incorrect. The linear no-threshold (LNT) model posits that there is *no* safe threshold dose; risk is assumed to increase linearly with dose down to zero dose. Therefore, any exposure, however small, carries some associated risk.
The average annual background radiation dose from natural sources in the United States is approximately 3 mSv (0.003 Sv).
Answer: True
This statement is accurate. The average annual dose from natural background radiation sources within the United States is estimated to be around 3 mSv.
A banana equivalent dose (BED) is a formal unit used in radiation protection, equivalent to 100 nanosieverts (nSv).
Answer: False
This statement is incorrect. A banana equivalent dose (BED) is an informal, illustrative unit used for comparison, not a formal unit of radiation protection. While a typical banana provides a small dose (around 98 nSv), the BED is not a standardized or official unit.
A single full-body CT scan typically results in an effective dose ranging from 10 to 30 mSv (0.01 to 0.03 Sv).
Answer: True
This statement is accurate. The effective dose from a full-body CT scan can vary but generally falls within the range of 10 to 30 mSv, depending on the specific imaging protocols employed.
Spending six months on the International Space Station results in a dose of approximately 80 mSv (0.08 Sv) due to increased cosmic radiation.
Answer: True
This statement is accurate. Astronauts on the International Space Station experience significantly higher radiation doses, estimated at approximately 80 mSv over a six-month mission, primarily from galactic cosmic rays and solar particle events.
A radiation dose of 4 to 5 sieverts (Sv) received over a short duration is considered the median lethal dose (LD50/30), indicating a 50% risk of death within 30 days.
Answer: True
This statement is accurate. A whole-body acute dose of approximately 4 to 5 sieverts is widely considered the median lethal dose (LD50/30) for humans, implying a 50% probability of mortality within 30 days without medical intervention.
A dose rate of 810 nSv/h near the Chernobyl New Safe Confinement is considered a low radiation level.
Answer: False
This statement is incorrect. A dose rate of 810 nSv/h (nanosieverts per hour) is equivalent to approximately 8 mSv per year if continuously present, which is significantly higher than typical background radiation levels and warrants caution.
The global average annual dose from natural background radiation is approximately 2.4 mSv.
Answer: True
This statement is accurate. The globally averaged annual dose from natural sources of background radiation is estimated to be around 2.4 mSv.
Residents in Taiwan living in apartments with Cobalt-60 rebar received an average accumulated dose of 400 mSv over several years without apparent adverse effects.
Answer: True
This statement accurately describes a documented case where residents in Taiwan received significant chronic radiation exposure (average 400 mSv over 9-20 years) from contaminated building materials, yet showed no observable adverse health effects, highlighting the complexity of radiation risk assessment.
According to the ICRP, what is the estimated probability of developing fatal cancer from one sievert of radiation exposure?
Answer: 5.5%
Based on the linear no-threshold model, the International Commission on Radiological Protection (ICRP) estimates that an effective dose of one sievert (Sv) corresponds to an approximate 5.5% increase in the probability of developing fatal cancer.
What is the fundamental assumption of the linear no-threshold (LNT) model regarding radiation exposure?
Answer: Risk increases linearly with dose, with no safe threshold.
The linear no-threshold (LNT) model assumes that the probability of stochastic effects, such as cancer, increases in direct proportion to the radiation dose, extending down to zero dose without a threshold below which the risk is considered zero.
What is the approximate average annual dose from natural background radiation in the United States?
Answer: 3 mSv
The average annual dose received by individuals in the United States from natural background radiation sources, such as cosmic rays, terrestrial radiation, and internal radionuclides, is approximately 3 mSv.
Which of the following dose levels represents a median lethal dose (LD50/30) of radiation?
Answer: 4-5 Sv
An acute whole-body radiation dose in the range of 4 to 5 sieverts (Sv) is considered the median lethal dose (LD50/30), indicating a 50% probability of fatality within 30 days for an exposed population without significant medical intervention.
Which of the following dose levels represents a significant occupational hazard, potentially leading to acute radiation sickness if exposure is prolonged?
Answer: 4-5 Sv
An acute whole-body dose of 4-5 Sv is considered the median lethal dose (LD50/30) and poses a severe risk of acute radiation sickness and death. While occupational limits are much lower (e.g., 50 mSv/year), accidental exposures can reach these dangerous levels.
What is the approximate effective dose from spending six months on the International Space Station?
Answer: 80 mSv
Astronauts aboard the International Space Station are exposed to significantly higher levels of radiation, primarily cosmic radiation. A six-month mission typically results in an effective dose of approximately 80 mSv.
What does the 'banana equivalent dose' (BED) illustrate?
Answer: A relatable, informal comparison for small radiation doses.
The banana equivalent dose (BED) is an informal concept used to help the public understand the magnitude of small radiation doses by comparing them to the natural radioactivity present in a banana. It is not a formal unit of measurement.
The dose rate inside the primary containment vessel of Fukushima's No. 2 reactor in February 2017 was measured at approximately 4.6 to 5.6 Sv/h. What does this indicate?
Answer: A level that poses a significant risk of acute radiation sickness within minutes.
A dose rate of 4.6 to 5.6 Sv/h is extremely high. At such levels, a lethal dose could be accumulated in a matter of minutes, posing an immediate and severe risk of acute radiation sickness and death, necessitating stringent protective measures and remote handling.
Which of the following is an example of a stochastic health effect from radiation?
Answer: Cancer induction
Stochastic effects, such as cancer induction and hereditary effects, are characterized by their probability of occurrence increasing with dose, without a threshold. Cataract formation, skin reddening, and sterility are examples of deterministic effects, which have a threshold dose and increase in severity with dose.
What is the approximate global average annual dose from natural background radiation?
Answer: 2.4 mSv
The global average annual dose from natural background radiation, encompassing sources like cosmic rays, terrestrial radiation, and internal radionuclides, is estimated to be approximately 2.4 mSv.