Radiation Effects and Sensitivity Quiz

Acute Somatic Effects

• No detectable effects for doses under 250 mSv
• Reduced blood cell count (red and white) for doses between 250 - 1,000 mSv
• Nausea, vomiting, and increased infection susceptibility for doses between 1,000 - 3,000 mSv
• Severe symptoms including diarrhea, hemorrhage, sterility, and 50% mortality within 30 days for doses between 3,000 - 6,000 mSv
• Intensified symptoms, CNS impairment, and death within 30 days for doses exceeding 6,000 mSv

High Cancer Sensitivity Organs

• Breast
• Bladder
• Ovary
• Bone marrow
• Blood

Moderate Cancer Sensitivity Organs

• Lung
• Liver
• Kidney
• Thyroid
• Prostate
• Cervix
• Skin

### Low Cancer Sensitivity Organs

• Brain

 Late Effects of Radiation

• Biological effects that manifest long after exposure to radiation
• Can be categorized into deterministic and stochastic effects

LD 50/30 and LD 50/60

• LD 50/30: Lethal dose for 50% of a population within 30 days (250–450 rad).
• LD 50/60: Lethal dose for 50% within 60 days (250–300 rad).

Deterministic Effects

• Predictable effects that occur only when radiation reaches a certain threshold
• Threshold Dose: Minimum amount of radiation required to damage specific tissues
• Examples: Cataract formation (eye), Reddening (erythema), hair loss, scarring (necrosis) (skin), Potential infertility (reproductive organs), Systemic failure (bone marrow damage, blood cell reduction, gastrointestinal damage, and CNS damage) (whole-body)

Stochastic Effects

• Effects with NO threshold, including cancer and genetic mutations
• Somatic Effects: Affect the individual exposed
• Genetic Effects: Mutations in germ cells that may result in birth defects in offspring

Cancer Induction

• Mechanism: Radiation can cause mutations that may lead to cancer
• Latency Period: Leukemia (5–15 years), Solid tumors (10–60 years)

Fetal Radiation Sensitivity

• Pre-implantation (up to day 9): High risk of spontaneous abortion
• Organogenesis (2–8 weeks): Increased risk of congenital abnormalities
• Fetal Growth (post day 45): Risks to nervous system, behavior changes, reduced IQ, cancer

Risk Levels by Trimester

• Highest Risk: Organogenesis (weeks 2–8)
• Moderate Risk: 2nd trimester
• Lowest Risk: 3rd trimester

Biological Effects Factors

• Dose: Amount of radiation absorbed by the body
• Dose Rate: Time over which the dose is received (Acute exposure: over seconds or minutes, Chronic exposure: over days/years)
• Type of Radiation: Different types of radiation impact different body areas
• Organ Sensitivity: Certain organs (e.g., eyes) are more sensitive than others (e.g., hands)
• Irradiated Area: Location of exposure matters (localized, extremities, full-body, deep tissue)
• Radiation Source: Can be external (outside body) or internal (incorporated into tissues)

External Radiation Effects

• High exposure can cause skin reddening (erythema), swelling (edema), hair loss (epilation), and cataracts

### Internal Radiation Effects

• Caused by ingested or inhaled radioactive materials
• More hazardous due to constant exposure within the body

Classification of Radiation Damage

• Somatic Effects: Impact the individual exposed
• Genetic Effects: Affect the offspring of the exposed individual
• Stochastic Effects: Randomly occur, but probability increases with dose
• Non-Stochastic Effects: Occur only if dose exceeds a certain threshold

Exposure Types

• Acute Exposure: Large dose in a short period; symptoms show soon after exposure.
• Chronic Exposure: Low doses over extended periods; effects may appear after a latent period

### Biological Damage Levels

• Damage can occur at various levels: sub-cellular, cellular, organ, and organism level
• Visible effects appear when millions of cells are affected

Categories of Biological Effects

• Acute Somatic Effects: Immediate effects on the exposed individual
• Delayed Somatic Effects: Appear years later
• Genetic Effects: Appear in offspring

### FANR

• UAE’s main regulator for nuclear activities, based on 2008 policy and 2009 law
• Manages licensing, inspection, and international agreements

NRC

• U.S.agency regulating by-products from reactors

High-Risk Populations for Radiation Effects

• American radiologists: Increased leukemia and reduced life spans
• Atomic bomb survivors: Malignant diseases and acute lethality
• Radiation accident victims: Increased thyroid cancer and other malignancies
• Uranium miners: Lung cancer due to radon exposure

Test your knowledge on the acute somatic effects of radiation exposure, including organ sensitivity levels and the late effects of radiation. This quiz covers various dose levels and their corresponding symptoms, as well as lethal doses for populations. Challenge yourself with this informative quiz on radiation biology.