Calculating radiation risk for a given population

In summary: This risk estimate of 5 in 100,000 per mSv is then multiplied by the effective dose of 60 mSv to estimate the number of individuals at risk, which in this case is 33 out of a population of 11,000. In summary, the Marshall Islands population, which was exposed to 1.5 Gy of thyroid dose from 131Iodine, is estimated to have 33 individuals at risk of death due to radiation exposure. This risk estimate is based on epidemiological studies and the effective dose of 60 mSv.
  • #1
Crocodile
6
0
Hi

This is the question...

The population of the Marshall Islands were exposed to fallout from atomic bomb tests in the middle of the last century. A significant quantity of the fallout was in the form of 131Iodine, a gamma emitter which is avidly absorbed by the human thyroid. The average thyroid dose received by an islander was 1.5 Gy. The population of the islands was approximately 11000. How many islanders might be expected to die following this exposure to their thyroids?

[Useful Data : the radiation weighting factor for gamma rays is 1 and the tissue weighting factor for the thyroid is 0.04]

and I have been given an answer to it:

Thyroid dose 1500 mGy, gamma emitter thus equivalent dose 1500 mSv

Effective dose is 1500 x 0.04 = 60 mSv

Risk is 5 in 100,000 per mSv
i.e. 300 in 100,000 (or 3 in 1000) for 60 mSv

In population of 11,000, 33 at risk

I understand everything up to where he says the risk is 5/100,000. Where has he got that from? If you know any better ways of answering the question, feel free to comment.


Thanks in advance!
 
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  • #2
The risk of 5 in 100,000 per mSv is estimated from epidemiological studies of large populations exposed to lower levels of radiation. For example, the Japanese atomic bomb survivors cohort and the British radiologists cohort. The International Commission on Radiological Protection (ICRP) uses these studies to develop its dose-response relationship for the effects of radiation on human health.
 
  • #3


Hi there,

The risk of developing cancer from exposure to radiation is often measured in units called "excess lifetime cancer deaths per unit of radiation dose." This is typically expressed as a fraction, such as 5 in 100,000. This means that for every 100,000 people exposed to a certain amount of radiation, we can expect 5 additional cancer deaths compared to the number of cancer deaths we would normally expect without the exposure.

In this case, the risk factor of 5 in 100,000 per mSv is based on data from the International Commission on Radiological Protection (ICRP) and is used to estimate the risk of developing cancer from a certain amount of radiation exposure. The risk factor takes into account the type of radiation (in this case, gamma rays), the type of tissue affected (thyroid in this case), and other factors such as age, gender, and overall health of the population.

As for other ways of answering the question, there are various mathematical models and methods used to estimate the risk of radiation exposure on a population. However, the approach used in the given answer seems to be a reasonable and simple way to estimate the number of potential deaths from the given exposure.
 

Related to Calculating radiation risk for a given population

What is radiation and how does it affect the human body?

Radiation is the emission of energy in the form of particles or waves. It can come from natural sources, such as the sun or radioactive elements in the earth, or from man-made sources, such as medical imaging equipment or nuclear power plants. When radiation interacts with the cells in our body, it can cause damage to our DNA, potentially leading to health effects like cancer or radiation sickness.

How is radiation risk calculated for a given population?

Radiation risk is calculated by considering several factors, including the type of radiation, the dose received, and the sensitivity of the population. Scientists use mathematical models and data from past studies to estimate the potential health effects of radiation exposure for a specific group of people. This allows for the prediction and prevention of potential health risks.

What are the different units used to measure radiation?

The most commonly used units to measure radiation are the Gray (Gy) and the Sievert (Sv). The Gray is used to measure the amount of radiation absorbed by an object, while the Sievert is used to measure the biological effects of that radiation. Other units, such as the Becquerel (Bq) and the Curie (Ci), are used to measure the rate at which a radioactive substance decays.

What are the sources of radiation exposure for the general population?

The main sources of radiation exposure for the general population include natural background radiation (from the sun and the earth), medical procedures (such as X-rays and CT scans), and consumer products (such as smoke detectors and granite countertops). Some populations may also be exposed to radiation from man-made sources, such as nuclear power plants or nuclear weapons testing.

How can we minimize radiation risk for a given population?

There are several ways to minimize radiation risk for a given population. These include using protective equipment, following safety protocols, and limiting exposure to sources of radiation. It is also important for individuals to be aware of their radiation exposure and to follow guidelines for safe levels of exposure. Additionally, continued research and monitoring of radiation levels can help inform policies and regulations to protect the population from unnecessary exposure.

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