AMAZING FACTS ABOUT RADIOACTIVITY “SCIENCE FACT IS STRANGER THAN SCIENCE FICTION!” Researched & Compiled by Bill DiPuccio

Incredible Energy Released by Radioactive Elements  Nuclear radiation is thousands and millions of times more energetic than radio waves, microwaves, visible light, and UV rays. Despite its name, radioactivity has no direct connection with radio waves.  Nuclear energy is thousands and millions of times more energetic than chemical energy. One gram of Uranium or Plutonium in a nuclear reactor releases the same amount of energy as 3,000 kg of coal. Whereas 1 kg of coal can propel a small electric car 4 km, 1 kg of Uranium or Plutonium can propel a small electric car 12 million km. That’s 3 million times more energy!  Half a gram of Poloniun-210 gives off so much energy as it decays, that it heats up to over 500 degrees C (932 F).  Globally, the heat of radioactive decay totals about 27 trillion (27 x 1012) watts per second and is believed to produce 45%-90% of the earth’s geothermal energy.  One gram of Radium-226 (which contains 2.6646 x 1021 atoms) decays at the rate of 37 billion (3.7 x 1010) disintegrations per second! Even at that rate, it would take about 2300 years for all the Radium to decay into other elements. As the number of Radium atoms decreases fewer atoms disintegrate, so it actually takes about 110,000 years for one gram to transmutate into other elements. Some elements decay billions and even trillions of times faster than this!

Radioactive Minerals—They’re Everywhere!  Trace amounts of radioactive elements are found throughout the earth in rocks, soil, water (ground water, oceans, lakes, etc.), building materials, the food chain, and the human body. They are usually more concentrated in granite, shale, clay, coal, and sandstone.  The most abundant radioactive elements are (listed in order): Thorium-232, Uranium-238, and Potassium-40. If we could scoop up one square mile of rock and soil to a depth of one foot, then extract all of the radioactive material from it, we would accumulate about 12,000 kg of Thorium, 2,200 kg of Uranium, 2,000 kg of Potassium-40, and 1.7 g of Radium.  These elements (especially Potassium-40) are absorbed by plants and passed up the food chain. Among the most radioactive foods are (listed in order): Seaweed (kelp), Brazil nuts, lima beans, bananas, carrots, white potatoes, and red meat. Salt substitutes are also radioactive because they contain Potassium-40.  Your body contains about 17 mg of Potassium-40 and 22 ng of Carbon-14. This means that over 440,000 radioactive atoms decay in your body every minute! Externally we are bombarded with nearly 1 million photons per minute from natural radioactive sources and cosmic rays.  There are over 100 radioactive minerals (uranium alone has over 50 minerals). However, only a small number of these minerals are common.  The fly ash emitted by a coal burning power plant produces 100 times more radiation in the surrounding environment than a nuclear power plant generating the same amount of energy.

Radiation & Health—Beware!  Radioactivity is a form of ionizing radiation, which means that it has enough energy to create ions by knocking electrons from atoms and molecules. This causes atoms to be chemically reactive. Ions are disruptive to cellular processes and result in tissue damage, often in the form of cancer. Cells which are dividing to create new cells are more susceptible to genetic mutation. These are found in the skin, the lining of the digestive tract, bone marrow (blood production), fetuses, and children.  The decay of Radium produces radioactive Radon gas which seeps into the atmosphere and sometimes collects in basements. Natural gas also contains traces of Radon. Radon decay produces radioactive dust particles (Polonium, Lead and Bismuth) which we inhale everyday.  Radon gas and its decay products are the single largest source of environmental radiation exposure and may be the second largest cause of lung cancer (up to 21,000 cases per year) next to smoking. You can check your basement for Radon gas with a $15 test kit. Why wait?  Tobacco contains radioactive elements (Polonium-210, Lead-210, Potassium-40) which can reach dangerous levels over time. Heavy smokers (1 pack/day) receive over 50 times the annual recommended dose limit of radioactivity.  Inhalation of radioactive particles poses a much greater threat to human health than ingestion, raising the cancer mortality risk ten to hundreds of times depending on the material. Most ingested material is eliminated from the body quickly through digestion. As with all radiation, the level of danger depends on the intensity and exposure time.  People and materials exposed to radioactivity do not become radioactive unless they are contaminated with the source material. However, near exposure to a nuclear reactor core or a nuclear explosion can induce radioactivity in materials and living tissue by neutron activation.

Your Radioactive House  Porcelain fixtures (toilets, sinks), vases, dishes, and figurines are slightly radioactive.  If you live in a brick house, or work in a stone building, you are exposed to slightly more radioactivity than someone who lives in a wood frame house. If your home has granite countertops, ceramic tiles, a fireplace, or uses natural gas, your exposure also increases.  Among the building materials used in North America clay bricks, granite, sandstone, and cement have the highest levels of radioactivity. Even wood is radioactive due to the uptake of Potassium-40 from the soil and Carbon-14 from the air.

TVs are X-Ray Machines  All tube type TVs produce X-rays. In fact, they operate on the same principle as an X-ray tube. The rays are contained by the thick leaded glass on the front of the screen. Early TVs were dangerous because they had thin glass screens allowing X-rays to escape the tube.  Radon decay particles collect readily on tube type TV screens (but not on flat screens) due to a negative static charge on the screen. Never put your face near the screen or allow children to wipe the dust from the screen! Collect the dust with a damp cloth and dispose of it safely.  Some plastics also pick up a negative static charge on their surface which rapidly attracts Radon decay particles. These include both latex and metallized-plastic party balloons.

Cosmic Rays—Invaders from Space  High energy cosmic rays (which are mostly protons) strike the atmosphere at nearly the speed of light. Collisions with atmospheric atoms at high altitudes result in fission (“spallation”) which produces secondary particles in the form of radioactive elements such as Carbon-14 and Hydrogen-3.  Secondary particles sometimes fall to the ground in cosmic ray “showers” about 100 m across and 12 m thick. Some secondary particles called muons (heavy electrons) can penetrate hundreds of meters beneath the earth and are easily detected by radiation counters.  The half-life of muons is about two microseconds. Even traveling near the speed of light they should disintegrate before reaching the ground. Why don’t they? According to the Einstein’s Special Theory of Relativity time slows for objects moving near the speed of light. This stretches the muon’s half-life, enabling it to strike the earth’s surface.  Exposure to cosmic radiation (produced mostly by solar flares) doubles about every 6,000 feet in elevation. So flight crews, frequent fliers, and people who live at higher elevations are exposed to slightly more radiation than ground huggers.

Radioactivity & Physics—Fathom This!  Because of its density, lead is often used as a shield against radioactivity. But improper use of lead can result in more radiation! X-rays are produced when radioactive Beta particles strike dense metals. These high speed electrons release energy as they rapidly slow down. The X-ray energy increases with the incident energy of the electrons, creating the potential for dangerous “hard” Xrays. Physicists call this “Bremsstrahlung” (German)—braking radiation.  Alpha particles, which are given off by many radioactive sources, consist of 2 protons and 2 neutrons. They are actually the nuclei of helium atoms. In fact, most of the helium in the earth’s crust is ‘recycled’ alpha particles. These relatively heavy particles travel at about 15,000 km/s (5% the speed of light). They pose little danger when outside the body because they travel only a few centimeters and can be stopped by your skin and clothes, or even a piece of paper. But inside the body they are highly destructive to soft tissue.  Beta particles, which are given off by many radioactive sources, are actually high speed electrons. Intense beta radiation can pose an external danger. They travel at about 180,000 to 270,000 km/s (60%-90% the speed of light) with a range of up to several m in the air. Three to four mm of aluminum are needed to shield the source. The tracks of both alpha and beta particles can be seen with a simple, homemade cloud chamber. Each beta decay also produces an (anti)neutrino—a nearly massless particle that can pass right through the earth at nearly the speed of light.  Gamma rays are the most penetrating of all radiation. They are not particles but electromagnetic waves with wavelengths of less than one trillionth of a meter (10 -12)—smaller than the size of an atom. High energy gamma rays can require up to several centimeters of lead shielding. Gamma rays emanate from the decay of most radioactive elements. Some emanate from space and infrequently from lightning flashes.  Pairs of matter and antimatter particles are created directly from energy (E=mc2) when certain radioactive elements give off high energy gamma rays as they decay. The creation and annihilation of antimatter electrons (called positrons) occurs in your body during a PET scan!  Radioactive decay is different than nuclear fission. Decay is a natural process that changes an atom into a different element with nearly the same atomic number (+1 or -2). Fission is an artificial process (with few exceptions) that uses neutron bombardment to split each atom into two or more lighter elements, releasing large amounts of energy. Dozens of radioactive elements are produced by fission reactors and fission bombs.

Radioactive Bits & Pieces  Many radioactive elements commonly used in medicine and industry are produced artificially in nuclear reactors. These include Tritium (H-3), Iodine-131 and 129, Cesium-137, Cobalt-60, Americium-241, Strontium-90, Technetium-99m and Plutonium-239.  Since it is impossible to predict when a radioactive atom will decay, mathematicians and scientists use radioisotopes to generate random numbers by measuring the interval between disintegrations. The decay rate and half-life of a radioactive element can only be determined by taking the statistical average of a very large number of atoms.  In the early 20th century, before the dangers of radioactivity were fully known, some believed that it had healing properties. An entire line of Radium based consumer products became available, including salves, beauty creams, toothpaste, tablets, ear plugs, chocolate bars, soap, bath salts, suppositories, contraceptives, pads, tonics, bread, deodorizers, spring water, and radioactive drinking water irradiated by Radium water crocks and “emanators”. The popularity of these quack cures ended in the 1930’s after some died of radiation poisoning. Several “curative” products are still marketed in Japan, and radon therapy is offered at the Free Enterprise Radon Health Mine in Montana. Radiation “hormesis,” the belief that low doses of radioactivity may actually be beneficial if not curative, has neither been falsified nor validated by available research and continues to be controversial.

Common Radioactive Items                         

Smoke Detectors ……………………………………….....…………………………….……………………………(Americium) Ceramic Tiles, Dishes, Vases, Figurines, etc. ........................................(Uranium, Thorium, Potassium-40) Porcelain Fixtures (sinks, toilets)……………….……………...……..…....(Uranium, Thorium, Potassium-40) Clay Bricks and Clay …………………………………….………………..…...…(Uranium, Thorium, Potassium-40) Cat Litter (clay based) ………………………………….………………..…..….(Uranium, Thorium, Potassium-40) Granite Countertops …………………………………….………………....…….(Uranium, Thorium, Potassium-40) Fertilizers ………………………………………………………………………....….(Uranium, Thorium, Potassium-40) Well Water (depending on location) …………………………………..….(Uranium, Thorium, Potassium-40) Brazil Nuts …..……………………………………………………………………....……………….(Radium, Potassium-40) Salt Substitutes ………………………………………………………………………..………………………….(Potassium-40) Seaweed (Kelp)…………………………………………………………………………...……...……………….(Potassium-40) Foods High in Potassium…..……………………………………………………..……..…...……………….(Potassium-40) Water Softener Pellets (Potassium Chloride)……………………………….…….…..……………..(Potassium-40) Cloisonné Jewelry (some types) ………………………………………………………...………………………..(Uranium) Antique Glassware (“vaseline glass”)……………………………..…………………………………………….(Uranium) Fiesta Ware (before 1973)……………………………..……………..…………………………………………….(Uranium) Zircon Jewelry ……………………………………………………………………………………………(Uranium, Thorium) Glass (especially optical and fine crystal)..……………………………….….……..….(Potassium-40, Thorium) TIG Welding Rods …………………………………………………………………………….……..………………….(Thorium) Gas Lantern Mantles (some brands)…………………………………………………………..………………...(Thorium) Dust on Tube Type TV/Computer Screen .……………...(Polonium, Lead, Bismuth from Radon Decay) Dust on Air Filters ………………………………………………...(Polonium, Lead, Bismuth from Radon Decay) Natural Gas…..…………………………………………………...…..(Polonium, Lead, Bismuth from Radon Decay) Tobacco …………………………………………………………….……………….(Polonium, Lead-210, Potassium-40) Tritium Glow Lights and Watches …………………………..…….……………………………………………….(Tritium)