- Background radiation is always present and must be subtracted in experiments
- Corrected count rate = Measured count rate − Background count rate
- Radon gas from rocks is the biggest source (~50% of UK background radiation)
- The UK average annual radiation dose is about 2.7 mSv
- Natural sources contribute about 85% of UK background radiation
- Medical sources are the largest artificial contributor (~14%)
- Nuclear power contributes less than 0.1% — often incorrectly thought to be a major source
- Background radiation is random — readings vary from moment to moment
- Higher altitude = more cosmic radiation (less atmospheric shielding)
- Granite rock areas (e.g. Cornwall) have higher background radiation due to radon
This key facts covers Key Facts within Background Radiation for GCSE Physics. Revise Background Radiation in Extra Topics for GCSE Physics with 13 exam-style questions and 12 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 7 of 12 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Background Radiation
What is background radiation?
Describe two natural sources and one artificial source of background radiation.
Quick recall flashcards
What are cosmic rays?
Radiation from space (from exploding stars) that contributes ~10% of background radiation
What is background radiation?
Low-level radiation that is always present in the environment from natural and artificial sources