bananas
about radioactivity
Going
Building materials
are radioactive.
This rock contains
dinosaur fossils
which are more
radioactive than the
surrounding rock.
Typical dose: 0.35
mSv per year.
Bananas are radioactive. They contain potassium-40,
a radioactive isotope that emits beta and gamma
radiation. If you eat one banana a day, your annual
exposure to radiation will increase by about 0.035
millisieverts (mSv). Other radioactive foodstuffs:
kidney beans, brazil nuts, peanut butter and coffee.
Typical dose: 0.27 mSv per year.
In a bone scan, the patient is
injected with radioactive material.
The radiation reveals the state of
their bones. Typical dose: 3.5 mSv.
Cosmic rays are
radiation from
space. They were
discovered in 1910
when Theodor
Wulff measured
more radiation at
the top of the Eiffel
Tower than at the
foot. Typical dose
at sea level: 0.25
mSv per year.
Radioactive radon gas seeps up from underground and
we breathe it in. Marie Curie drove a mobile clinic which
used gamma radiation from radon to X-ray soldier’s
injuries in WW1. Typical dose: 1.3 mSv per year
22
Catalyst February 2012