Radioactivity and Radiation
Background radiation is present everywhere around us, and can be detenced by a Geiger counter.
Most commonly, radon gas makes up the background radiation in our atmosphere (50% of it) this is because it occurs naturally, although some places more than others in the UK. Rocks contain small traces of radioactive isotopes - making them naturally radioactive.
> Granite, in particular, is slightly more radioactive than other rocs because it contains higher levels of uranium atoms. When the uranium nuclei decays naturally over time, it produces a radon nuclei. Radon is colourless and odourless.
Facts about radon gas:
> Houses built over granite can trap radon gas
> Exposure to radioactive radon can lead to lung cancer
> Some areas in the UK have more radon gas in the atmosphere on others depending on how much granite is in the area.
> Different areas in the UK also have different levels of background radiation due to varying amounts of radioactive sources in that region (e.g cities are more likely to have more background radiation than rural areas)
> It is particularly dangerous if it remains trapped in walls of buildings or under floorboards
> Radon is a non-reactive noble gas and therefore itself is not a health hazard
> It is believed that radon-222 may cause cellular damage in the lungs
Natural sources of background radiation:
Cosmic Rays: energetic particles such as electrons, protons and neutrinos that come from the Sun and outer space are cosmic rays. They penetrate the Earth's atmosphere to reach the surface. The danger from cosmic rays increases with altitude because there is less atmosphere to stop radiation.
Rocks: rocks such as granite contain uranium, which decays to produce radioactive radon gas.
Food: all foods have minute traces of radioactive nuclei.
Humans sources of background radiation:
Nuclear Power Stations
Fallout: from previous nuclear weapons tests, explosions and accidents
Radiation: from equipment or waste from hospitals and industry.
Uses of Radioactivity
Gamma: Irradiating food with gamma rays to prolong its shell-life. The gamma rays kill off microorganisms on the food even after it has been packaged. In the metal industry, gamma rays are used to check the quality of welding or to detect cracks in metals.
Beta: Beta particles are used in the water industry to detect leaks in underground pipes. A beta-particle emitting radioactive material, known as a tracer, is fed into the pipe. Above ground, a radiation detector detects increased levels of radiation.
Beta particles can also be used as a source…