Noadswood Science, 2012 RADIOACTIVE SOURCES & THEIR DANGERS

Radioactive Sources & Their Dangers To know the dangers associated with different radioactive sources Friday, February 12, 2016

Detecting Radiation Radiation cannot be detected by human senses, so requires machines to do so… Photographic film goes darker when it absorbs radiation, just like it does when it absorbs visible light – the more radiation the film absorbs, the darker it is when it is developed People who work with radiation wear film badges, which are checked regularly to monitor the levels of radiation absorbed

Detecting Radiation There is a light-proof packet of photographic film inside the badge – the more radiation this absorbs, the darker it becomes when it is developed To get an accurate measure of the dose received, the badge contains different materials that the radiation must penetrate to reach the film These materials may include aluminium, copper, lead-tin alloy and plastic There is also an open area at the centre of the badge

Detecting Radiation The Geiger-Muller tube detects radiation – each time it absorbs radiation, it transmits an electrical pulse to a counting machine which makes a clicking sound or displays the count rate The greater the frequency of clicks, or the higher the count rate, the more radiation the Geiger-Muller tube is absorbing

Radiation Dangers When radiation collides with molecules in living cells it can damage them If the DNA in the nucleus of a cell is damaged, the cell may become cancerous – the cell then goes out of control, divides rapidly and causes serious health problems The greater the dose of radiation a cell gets, the greater the chance that the cell will become cancerous However, very high doses of radiation can kill the cell completely – used to kill cancer cells, and also harmful bacteria and other micro-organisms

Radiation Dangers If radiation enters your body it will collide with molecules in your cells These collisions cause ionisation, which damages or destroys the molecules (lower doses tend to cause minor damage without killing the cell, whilst higher doses can kill the cell completely) α β and γ

Radiation Dangers – Inside The Body α If the radioactive source is inside the body, perhaps after being swallowed or breathed in: - Alpha radiation is the most dangerous because it is easily absorbed by cells Beta and gamma radiation are not as dangerous because they are less likely to be absorbed by a cell and will usually just pass right through it

Radiation Dangers – Outside The Body If the radioactive source is outside the body: - Alpha radiation is not as dangerous because it is unlikely to reach living cells inside the body Beta and gamma radiation are the most dangerous sources because they can penetrate the skin and damage the cells inside βγβγ

Radiation Poisoning There have been a few high-profile cases of radiation poisoning, including the Chernobyl disaster and the death of the ex-KGB spy Alexander Litvinenko… Japanese woman suffering burns from thermal radiation of the WWII atomic bomb, dropped by the USA

Radiation Poisoning – Chernobyl The Chernobyl disaster (26/04/1986) was a nuclear reactor accident in the former Soviet Union – it was the worst nuclear power plant disaster ever, resulting in a severe release of radioactivity into the environment following a massive power excursion which destroyed the reactor Two people died in the initial steam explosion, but most deaths from the accident were attributed to radiation poisoning

Chernobyl

Radiation Poisoning – KGB Poisoning Alexander Litvinenko was an officer within the KGB In 1998 he made various accusations against numerous KGB officials, and was dismissed followed by a subsequent arrested (acquitted) He fled from his re-trial to London, and as a writer accused Putin and other figures in the Russian government of a range crimes, including ordering the murder of Russian journalist Anna Politkovskaya On 01/11/2006 Litvinenko suddenly fell ill, in what was established as a case of poisoning by radioactive polonium-210 resulting in his death on 26/11/2006

KGB Poisoning

Radiation – Exposure

Radiation – Prognosis