Three Steps of Measurement
- Source (Becquerel): How much radiation is coming out of the object?
- Absorption (Gray): How much radiation was absorbed by the material?
- Impact (Sievert): How much biological damage did it do to a human?
The "Banana Equivalent Dose"
Bananas contain naturally occurring potassium-40, which is radioactive. Eating one banana exposes you to about 0.1 microsieverts (μSv). This is a tiny, harmless amount.
Typical Doses
- Dental X-ray: 5 μSv
- Flight from NY to LA: 40 μSv
- Annual Background Radiation: 3,000 μSv
Key Takeaways
- Microsieverts (μSv) are small; Sieverts (Sv) are huge
- Distance is your best protection from radiation
- Not all radiation is "bad"—the sun is a giant nuclear reactor!