Deterministic effect
Deterministic effects are the effects of radiation on exposed individual that have a threshold dose value below which they do not appear. For example, cataract, blood count changes, erythema, infertility as given in. Above the threshold dose value, the severity of the deterministic effect is increased as the dose is increased. This may be included by either acute or chronic exposure[1].
The impacts of radiation exposure from nuclear power are primarily stochastic. Even in the accident at Chernobyl, relatively few workers received high enough acute radiation doses to cause either death within a few months or other deterministic effects. Much larger populations were exposed to lower doses. The predicted appearance of cancer in these populations is delayed, typically by more than 10 years after the time of exposure and it is not possible to identify specific individual victims[2].
Types of deterministic effects
Radiation effects are classified as:
- Early effects
- Late effects
Early effects have a threshold dose, above which it will be seen, whereas late effects have no dose limits. Early deterministic effect occurs every time a certain radiation dose level or threshold dose exceeded. Therefore, the risk of deterministic effects attributed to the exposures likely to be encountered in diagnostic nuclear medicine procedures is nil. Deterministic effects include reddening of the skin, sterility, cataracts, radiation sickness, and even death if the dose is high-dose levels exceed. Late effects happen only to a certain percentage of individuals in a group that is exposed to a given hazard. The principal stochastic effect from radiation doses associated with diagnostic nuclear medicine is cancer. Hereditary effects manifested in the offspring of exposed individuals are less likely. Incident of cancer in radiation workers is not more than in general population[3].
Absorbed doses in radiology
To understand the significance of deterministic effects in diagnostic radiology, it is necessary to know the dosed patients or staff might receive. In general the dose are no more than a few tens of mGy, indicating little significance of threshold does in diagnostic radiology. Computed tomography scans can result in relatively high eye doses in the region of several tens of mGy. Although this may be much less than the threshold dose, the possibility of the patient having several scans over their lifetime linked to the cumulative nature of the effect makes it good practice to use techniques that will minimize the dose to the lens[4].
Examples of Deterministic effect
- Cataract: Cataract is a condition in which the lens of the eye becomes cloudy and opaque, resulting in a decrease in vision. It is a deterministic effect of radiation which has a threshold dose value of 0.5 Gy for the lens of the eye. Above this threshold dose value, the severity of the cataract increases as the dose is increased.
- Blood Count Changes: Blood count changes is a deterministic effect of radiation which is caused by the destruction of red blood cells. The threshold dose for this effect is 0.5 Gy and above the threshold, the severity of the blood count changes increases as the dose is increased.
- Erythema: Erythema is a skin condition which is characterized by redness and swelling. It is a deterministic effect of radiation which has a threshold dose of 0.5 Gy. Above this threshold dose value, the severity of the erythema increases as the dose is increased.
- Infertility: Infertility is a condition in which a person is unable to conceive a child. It is a deterministic effect of radiation which has a threshold dose value of 0.5 Gy. Above this threshold dose value, the severity of the infertility increases as the dose is increased.
Advantages of Deterministic effect
Deterministic effects of radiation have a number of advantages. These include:
- The threshold dose value allows for a clear determination of the level of radiation exposure necessary to produce a deterministic effect. This helps to inform decisions regarding the safe level of radiation exposure, as well as provide a base line for assessing risk in future exposures.
- The severity of the effect is proportional to the dose of radiation received, meaning that it is easy to ascertain the level of risk associated with a certain dose of radiation.
- The effects of deterministic radiation exposure can be easily monitored and studied due to their clear and predictable nature, with medical professionals being able to accurately assess the damage caused to an individual.
- The effects of deterministic radiation are often reversible if the exposure is stopped, allowing for potential recovery.
Limitations of Deterministic effect
- Deterministic effects are only produced above a certain threshold dose, and thus any effects below this are not usually observed.
- They are also limited by the fact that they may not be immediately observable and may take time to manifest.
- Deterministic effects also depend on the level of exposure to radiation, meaning that individuals with lower exposure might not suffer from the effects even though they are exposed to the same radiation.
- Furthermore, the severity of the effects can vary from individual to individual, depending on their level of exposure and general health condition.
- Lastly, the effects of deterministic radiation can be permanent and can have long-term implications for individuals exposed to the radiation.
Other approaches related to Deterministic effect include:
- Risk assessment: This approach involves analyzing the risk associated with radiation exposure and how it might affect an individual’s health. It also includes determining the probability of an adverse effect and the severity of the effect that might occur.
- Risk management: This approach involves developing strategies to reduce the risks associated with radiation exposure. This involves identifying potential sources of radiation, setting limits on exposure, and implementing protective measures.
- Radiation protection: This approach involves minimizing radiation exposure to individuals by implementing safety measures and providing information and education on radiation protection.
- Radiobiology: This approach involves studying the effects of radiation on living organisms, including the short-term and long-term effects of radiation exposure.
Other approaches related to Deterministic effect include risk assessment, risk management, radiation protection, and radiobiology. These approaches involve analyzing the risks associated with radiation exposure, developing strategies to reduce risk, minimizing radiation exposure, and studying the effects of radiation on living organisms.
Footnotes
| Deterministic effect — recommended articles |
| Stochastic effect — Qualitative risk analysis — Cyclic variation — Residual disability — Pure risk — Downside deviation — Exposure units — Indirect loss — Trading channel |
References
- Allisy-Roberts P.J., Williams J., (2007),Farr's Physics for Medical Imaging, Elsevier Health Sciences, Edinburgh.
- Bodansky D., (2007), Nuclear Energy: Principles, Practices, and Prospects, Springer, Seattle.
- Prakash D., (2014), Nuclear Medicine: A Guide for Healthcare Professionals and Patients, Springer, Mumbai.
- Sureka C.S., Armpilia Ch., (2017), Biology for Medical Physicists,CRC Press, New York.
Author: Klaudia Piotrowska
