Page 15 - Professorial Lecture - Prof Oyedele

3.3 FACTORS CONTRIBUTING TO HIGHER LEVELS OF IONIZING RADIATION

Director of Ceremony, as could be expected, there are some factors that
can contribute to higher levels of radiation or contribute to the threat posed
by ionizing radiation. Some of these factors are:

Uranium mining activities

As uranium is mined, there is more radioactivity and this can lead to higher
levels of radiation. However, the mining companies take measures to
minimize the radiation or keep the level of radiation to a minimum.

Accidental fallout from neighbouring countries

If a neighbouring country is operating a nuclear power reactor and there is
accidental fallout from the reactor, there could be an increase in the level
of ionizing radiation in the countries surrounding it. An example is the
Chernobyl nuclear accident in April 1986, in Ukraine.

Trafficking and theft

Trafficking or smuggling or theft of radioactive materials may expose
innocent people to high levels of radiation. This is because you may not
know if the person sitting near you in a vehicle or in a public place is carrying
a radioactive material. Or you may not know if radioactive material is
illegally kept in the room or office adjacent to yours. Of course, as I said
earlier, we cannot see or smell radiation.

Orphan sources

Orphan sources are, generally, small radioactive sources produced
legitimately and used for activities such as radiography, medical
radiotherapy or irradiation, electricity generation in radioisotope
thermoelectric generators, etc. But the sources were later abandoned or
lost or misplaced or stolen. Consequently, they are no longer subject to
regulation and they could be taken – either knowingly or unknowingly - to
the general public without any shielding.