Background radiation sources question

In summary, the main sources of background radiation include radon gas, cosmic rays, and ingested radioactive elements from food and drink. Artificial sources, such as medical imaging and nuclear testing, also contribute to the overall background radiation. The relative importance of these sources varies depending on location, with radon and other naturally occurring sources being the most significant contributors overall. However, the exact percentages of contribution can vary.
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AN630078
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Homework Statement
Hello, I have been revising and found a question concerning background radiation. I am not struggling too greatly to name the sources of background radiation but rather in understanding what the question is asking;

"Name the main sources of background radiation and state their relative importance"

By stating their relative importance does this mean state how greatly they contribute to the total background radiation? And perhaps considering how afflicting these sources are in relation to their dose? i.e. although radon gas is arguably the largest contributor less people are afflicted by this natural source than say the victims of the bombings of Hiroshima, even thought the total contribution of nuclear weapons is substantially less at ~0.3%.
Thank you to anyone who replies 👍
Relevant Equations
Background radiation
Several sources of background radiation include;
  • Radon gas from soil, rocks and building minerals; since radon is produced by the decay of uranium ore present in certain rocks e.g. granite. On Earth, approximately 42-51% of background radiation is the result of naturally radioactive gases like radon.
  • Cosmic rays; being charged particles from the the Sun and stars that collide with atoms in Earth’s upper atmosphere and magnetic field to produce an air shower of radiation, typically beta and gamma radiation, although most do not reach the surface of the Earth, contributing ~10-14% of the overall background radiation. The dose from cosmic radiation varies in due to differences in elevation and to the effects of the earth’s magnetic field at different locations on Earth.
  • Another source of radiation is ingested internally from food and drink; as two of the essential elements of the human body, being potassium and carbon, have radioactive isotopes that significantly contribute to the background radiation dose on Earth at 9-12%.
  • There are abundant artificial sources also, since human activity has contributed to the overall background radiation through the use of medical X-rays, implementing nuclear weapons testing and producing radioactive waste from nuclear power stations.
    • In particular, medical imaging, e.g. using X-rays, and employing radioisotopes for diagnostics and radiation treatment contribute 12-15% of the overall background radiation.
    • Nuclear testing in the between the 1940s-1960s resulted in a substantial increase in radioactive contamination which affected not just the immediate surrounding area but additionally dispersed globally, i.e as a result of nuclear fallout, contributing ~ 0.3%
My query is I do not know whether I have suitably responded to this question, specifically in discussing their relative importance.
 
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  • #2
AN630078 said:
"Name the main sources of background radiation and state their relative importance"
It would help if there was some context to the question. What course is asking this question?

My first thought on reading that statement was to think of the cosmic microwave background radiation (CMBR) which has significant importance to the big bang theory, but your answers seem to suggest a course looking for importance to human health.
 
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Halc said:
It would help if there was some context to the question. What course is asking this question?

My first thought on reading that statement was to think of the cosmic microwave background radiation (CMBR) which has significant importance to the big bang theory, but your answers seem to suggest a course looking for importance to human health.
Thank you for your reply. This is just a a standard A-Level question I was revising, focusing on the topic on nuclear radiation.
 
  • #4
I think it makes sense to "state their relative importance" by comparing 2 factors amongst sources: radiation doses and the source's radiation's effects.
For the doses comparison, you can visit the "National Council on Radiation Protection & Measurements (NCRP), Report No. 160", while for the effects I think you can research about "effects on human" and "role in science".
 
  • #5
AN630078 said:
By stating their relative importance does this mean state how greatly they contribute to the total background radiation?"
Yes - but biggest-to-smallest is sufficient (unless your syllabus specifically requires you to learn approximate percentages - which is extremely unlikely).

AN630078 said:
And perhaps considering how afflicting these sources are in relation to their dose?
No. The wording in the question would be much more specific if that were required.

The amount of detail required in the answer depends on how many marks are allocated. Suppose there are 4 marks. Try to make 5 points to cover yourself. In this case my answer would be:

The main contributors to background radiation are (in order):
- radon (alpha emitter) produced by naturally occurring radioisotopes in the earth’s crust;
- other naturally occurring radioisotopes in rocks and building material;
- artificial sources (e.g. medical sources, nuclear power plants);
- cosmic rays.
The above relative importance may be location-dependent. E.g. the above ordering might not apply near Chernobyl (leakage of artificial sources).

Note 1. I haven't included food/drink in the above list as the question is about background radiation, not human exposure level.

Note 2. If you get the chance, look through old papers and their mark-schemes. You can then see what level of detail is required for these descriptive types of question.
 

Related to Background radiation sources question

1. What is background radiation?

Background radiation refers to the low levels of ionizing radiation that are present in the environment at all times. It comes from a variety of natural and man-made sources, and is a normal part of our daily lives.

2. What are some common sources of background radiation?

The most common sources of background radiation include cosmic rays from outer space, radioactive elements in the Earth's crust, and radon gas. Other sources include medical procedures, such as X-rays, and nuclear power plants.

3. Is background radiation harmful to humans?

At low levels, background radiation is not considered harmful to humans. However, prolonged exposure to high levels of radiation can increase the risk of cancer and other health effects. It is important to limit exposure to radiation when possible.

4. How is background radiation measured?

Background radiation is typically measured in units of millisieverts (mSv) or microsieverts (μSv) per year. This measurement takes into account both the amount of radiation and the potential harm it can cause to human health.

5. Can background radiation levels be reduced?

While background radiation is a natural part of our environment, there are ways to reduce exposure to it. For example, limiting time spent near sources of radiation, such as X-ray machines, and using protective shielding can help reduce exposure. Additionally, monitoring and regulating sources of man-made radiation can help keep background radiation levels as low as possible.

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