Radiation Safety and Biological Effects Vocabulary Flashcards

Flashcards on radiation protection dose limits, SI units, ionization mechanisms, cellular sensitivity, and deterministic vs. stochastic effects.

Whole Body Occupational Annual Limit

The annual whole-body effective dose limit for an occupational radiation worker, set at $50\,\text{mSv}$.

Cumulative Occupational Dose Limit

The total lifetime dose limit for an occupational worker calculated by multiplying their age by $10\,\text{mSv}$.

Lens of the Eyes Occupational Limit

The annual radiation dose limit to the lens of the eyes for an occupational worker, set at $150\,\text{mSv}$.

Skin, Hands, and Feet Occupational Limit

The annual radiation dose limit to the skin, hands, and feet for an occupational worker, set at $500\,\text{mSv}$.

Frequent Exposure Limit (General Public)

The annual effective dose limit for members of the general public experiencing frequent exposure, set at $1\,\text{mSv}$.

Infrequent Exposure Limit (General Public)

The annual effective dose limit for members of the general public experiencing infrequent exposure, set at $5\,\text{mSv}$.

Embryo and Fetus Dose Limits

The radiation dose limit for an embryo or fetus during pregnancy, set at $0.5\,\text{mSv}$ per month and $5\,\text{mSv}$ total for the entire gestation period.

Dosimeter Placement

A radiation monitoring device worn at the collar level outside of a lead apron, with a second device worn at waist level for pregnant workers.

Radon

A naturally occurring background source of ionizing radiation from the earth that represents the largest natural radiation exposure.

Exposure in Air Unit

Quantifies radiation ionization in surrounding air, measured in Grays ($\text{Gy}_a$) or Coulombs per kilogram ($\text{C/kg}$).

Absorbed Dose Unit

Quantifies the amount of radiation energy absorbed inside body tissue, measured in Grays ($\text{Gy}_t$).

Effective Dose Unit

Measured in Sieverts ($\text{Sv}$) to express the type, safety limit, and biological danger of radiation inside the human body.

Becquerel

The System International (SI) unit used to measure the radioactivity of an element or substance.

Radiation Weighting Factor ($W_r$)

A factor reflecting relative biological harm, set at $1$ for X-ray photons and $20$ for alpha particles.

Ionization

The process where an X-ray photon strikes an atom and ejects an electron, creating an ion pair consisting of a free electron and a positively charged atom.

Germ Cells

Reproductive cells (sperm and ova) containing 23 chromosomes that are highly radiosensitive and cause genetic defects in future generations if damaged.

Somatic Cells

All non-reproductive body cells containing 46 chromosomes that express radiation damage directly in the exposed individual or fetus in utero.

Law of Bergoni and Trebondo

A biological principle stating that cell radiosensitivity depends on age, differentiation, metabolic rate, and mitotic rate.

Radiosensitive Cells

Cells that are easily damaged by radiation, characterized by being younger, nonspecialized, highly metabolic, or rapidly dividing.

Radioresistant Cells

Cells that can withstand higher radiation doses without damage, characterized by being older and highly specialized, such as nerve cells.

Acute Radiation Syndrome (ARS)

A predictable short-term condition resulting from massive whole-body radiation exposure, severely affecting the hematological, gastrointestinal, or central nervous systems.

Deterministic Effects

Short-term biological effects that require a specific dose threshold to occur and whose severity is directly dependent on the dose received.

Stochastic Effects

Long-term biological effects (such as cancer) that occur randomly without a threshold, where higher doses increase the risk rather than severity.

Erythema

Reddening of the skin caused by radiation exposure, occurring at a deterministic threshold of $2,000\,\text{mGy}$.

Epilation

Hair loss resulting from radiation exposure, occurring at a deterministic threshold of $3,000\,\text{mGy}$.

Oligospermia

Low sperm count in males caused by radiation exposure, occurring at a deterministic threshold of $150\,\text{mGy}$.

Miscarriage Threshold

The deterministic radiation exposure threshold during pregnancy that can cause a miscarriage, set at $100\,\text{mGy}$.

ALARA

An acronym standing for 'As Low As Reasonably Achievable,' achieved through time minimization, distance maximization, and shielding.