Chemicals in cigarettes and cigarette smoke are known to cause not only cancer but also other serious health problems. Many of the chemicals are poisonous. If a person ate one pack of cigarettes, he/she would die.
Radon is a naturally occurring radioactive gas that is formed when uranium decays in the soil. Uranium is in geological formations throughout North Carolina. When homes or other buildings are built on top of these geological formations, radon is pulled into the home and can concentrate to dangerous levels.
Radon is a decay product of the radium salts used in the luminous paint of the numerals. In this 1950's clock, the glass casing has accumulated 10 -16 gram) of radon. Image adapted with permission from Prof James Marshall 's (U. North Texas, USA) Walking Tour of the elements CD.