Radiocarbon dating half lives
In addition to this internal exposure, humans also receive external exposure from radioactive materials that remain outside the body and from cosmic radiation from space.
When these detectors’ sensitive structures are based on single diodes, they are called semiconductor diode detectors.
Radon is a decay product of uranium, which is relatively common in the Earth’s crust but more concentrated in ore-bearing rocks scattered around the world.
Radon seeps out of these ores into the atmosphere or into ground water; it can also infiltrate into buildings.
This is four times more than the worldwide average artificial radiation exposure, which in the year 2008 amounted to about 0.6 m Sv per year.
In some wealthier countries, such as the US and Japan, artificial exposure is, on average, greater than the natural exposure, due to greater access to medical imaging.