Radiation Effects Flashcards
Radiation effects
- Somatic effects
- Genetic effects
- Non-stochastic. Deterministic effects
- Stochastic/ Probabilistic effects
living beings/ person exposed to ionizing radiation that suffer biological damage to tissues
Somatic effects
Minutes, hours, days, weeks of the time of radiation exposure
Early somatic effects
High dose (early somatic effects) effects
- Nausea
- Fatigue
- Erythema
- Epilation
- Blood disorders
- Depression of sperm count
- Temporary/ Permanent sterility
- Intestinal disorders
- Fever
- Dry and moist desquamation
4 Stages of ARS (Acute Radiation Syndrome)
- Prodromal
- Latent
- Manifest
- Recover/ Death
Prodromal Stage (ARS)
- mins to hrs
- above approx 1Gy (100rad) delivered to total body, s/s of radiation sickness
- lasts for few hrs to couple of days
Latent Stage (ARS)
- lasts for hrs/ less (>50rad) to wks (1-5Gy)
Worst stage of ARS
Manifest
Syndromes acquired during manifest stage of ARS
a. Hematologic syndrome
b. Gastrointestinal syndrome
c. CNS/ cerebrovascular syndrome
RBC/ WBC reduction
Hematologic syndrome
Hematologic syndrome rad’n source
200-1000 rad (2Gy-10Gy)
Hematologic syndromej mean survival time
10-60 days
Hematologic syndrome clinical s/s
- Nausea
- Vomiting
- Diarrhea
- Anemia
- Leukopenia
- Hemorrhage
- Fever
- Infection
Damage in SI and LI lining
Gastrointestinal syndrome
Gastrointestinal syndrome rad’n source
1000-5000 rad (10Gy-50gy)
Gastrointestinal syndrome mean survival time
4-10 days
Gastrointestinal syndrome Clinical s/s
all 8 of hematologic syndrome s/sm plus
9. electrolyte imbalance
10. lethargy
11. fatigue
12. shock
Fluid elevation in brain
CNS/ cerebrovascular syndrome
CNS/ cerebrovascular syndrome rad’n source
> 5000 rad (50Gy)
CNS/ cerebrovascular syndrome clinical s/s
all 12 of GI syndrome s/s, plus
13. Meningitis
14. Ataxia
15. Edema
16. vasculitis
Mistakenly thought as “Early Recovery” because there is no visible s/s
Latent Stage
Amount of functional damage sustained will determine the potential for recovery
Repair mechanism (repair and recovery)
Dose of rad’n expected to cause death within 60 days to 50% of those exposed
Lethal dose 50/60: Acute Radiation Lethality
Recovery/ Death Stage Mean survival time
Average time between exposure and death
(1): only part of the body is irradiated; (2) dose is necessaty to have a esponse
- Local tissue damage
- higher
Cell death- tissue/ organ shrinkage ((1))
- atrophy
Manifests months-yrs after exposure to ionizing rad’n
Late Effects (Somatic)
Late effects (somatic) result from:
- Whole/ partial body acute high radiation doses
- production of individual low doses and chronic low level doses sustained for several years
Major types of late somatic effects
- Stochastic/ Probabilistic effect
a. Carcinogenic
b. Embryogenic effect (birth defect)\ - Non-stochastic effect
a. Cataractogenesis
b. Non-specific life span shortening
Biologic effects of ionizing rad’n on future generation
Genetic effects
Results of radiation-induced damage to the DNA molecule in the sperm/ova of an adult
Genetic effects
When these germinal mutations occur, faulty genetic info is transmitted to the offspring, whicg may manifest itself as various diseases/ malformations
Genetic effects
Exhibits a threshold below (effect does NOT normally occur) and above wherein biological damage increases as dose increases
Non-Stochastic/ Deterministic Effects
Acute Radiation Syndrome (ARS) is an example of what effect?
Non-Stochastic/ Deterministic Effects
Increasing severity w increasing radiation dose
Non-Stochastic/ Deterministic Effects
Principal deterministic effects of radiation exposure on humans and the approximate threshold dose
- Death: whole body- 200rad
- Hematologic depression: wb- 25rad
- Skin erythema: small field- 200 rad
- Epilation: sf- 300rad
- Chromosome aberration: wb- 5rad
- Gonadal dysfunction: local tissue- 10rad
Early effects (Non-stochastic)
- Erythema
- Decrease in WBC count
- Epilation
Other more serious early consequences of radn sickness
- Hematologic/ Hematopoietic syndrome
- GI syndrome
- Cerebrovascular syndrome
Late effects (Non-stochastic)
- Cataract formation
- Fibrosis
- Organ atrophy
- Loss of parenchymal cells
- Reduced fertility
- Sterility
Probability/ frequency of the biologic response to rad’n as a function of radiation dose
Stochastic/ Probabilistic Effects
No minimal safe dose exist
Stochastic/ Probabilistic Effects
Disease incidence increase proportionally with dose and there is no threshold dose
Stochastic/ Probabilistic Effects
Stochastic/ Probabilistic Effects examples
Cancer and Genetic Alteration
has an “all or non response”
Cancer and Genetic Alteration
May develop when ionizing rad’n damages reproductive cells that could bring about injuries consequences in subsequent generations
Mutation
Mutation example/s
Teratogenesis
Mutagenesis
Birth defect induced by irradiation of the unborn child in utero
Teratogenesis
Birth defect induced by irradiation to the reproductive walls before conception
Mutagenesis
