#1 Spark Plugs
Spark plugs with radioactive polonium-210 are highly collectible and very hard to find. Polonium-210 has been immortalized by the KGB spy who ingested the radioactivity and died three weeks later due to acute radiation poisoning.
Spark plugs are used to deliver electric currents through engines. In 1929, a patent was granted to the Firestone Rubber and Tire Company to add polonium-210 to their gapping electrode. In essence, adding a ‘spark’ of radioactivity to the gap was supposed to give the vehicle better performance. It was designed to help the engine start more efficiently to make the engine run better overall.
It took another 11 years from concept to reality. The only Po-210 spark plug was produced in 1940 by Firestone. There are no definitive outcomes for the product, but there were a few problems. The material is not easy to obtain in large quantities due to its dangerous alpha emissions, and its short half life. The radioactive half life of Po-210 is 138 days. Roughly every 4 months, the spark plugs would have to be replaced in order to continue to be effective.
Cigarettes have a long list of toxic ingredients. The tobacco used in cigarettes is grown in soil that naturally contains radioactive materials. The leaves can contain polonium-210, a radioactive material with a half life of 138.3 days and lead-210 with a half life of 22 years. Concentration in the leaves is dependent on soil richness, area of growth and fertilizers.
Polonium-210 is an alpha emitter. When the cigarette smoke is inhaled, so are the alpha particles. The lungs are unable to filter out this type of radiation and damage can be severe. The chemicals in cigarette smoke cause damage to the cleansing system and the alpha particles remains in the airway and lungs to do their damage.
Over time, the alpha particles that are trapped build up in the lungs. This build-up can create long term radiation exposure to the airways and lungs. There is no proof that this is the cause of lung cancer, but the addition of any radioactive element increases the risk of cancer to those who are exposed in contrast to those who are not exposed.
# 3 Glossy Magazines
The product Kaolin is added to paper filling in the fibers to give it a glossy and smooth surface. Kaolin is named for the area in China called Kao-Ling where clay is mined to produce porcelain. Kaolin is a white clay that when mixed with wood pulp fills in the spaces in paper to form a coated, smooth surface. This product is mostly used in the magazine industry for its more aesthetic look when printing pictures.
The state of Georgia in the United States is currently the largest producer of Kaolin. It is referred to as ‘white gold’.
Kaolin white clay contains small amounts of the uranium decay series and thorium decay series. Researchers determined the amount of radioactivity in magazines for one hour resulted in approximately 0.15-0.35 pCi/gram of uranium series. The thorium series was 0.3-0.6 pCi/gram which translates to 0.0015 µrem/hr. In order to put this into perspective, background radiation exposure is 0.008 mrem/hr.
The fact that glossy magazine are radioactive just means they are more radioactive than regular paper.
Andy Bauer started creating pottery in 1878 in the form of whiskey jugs and crocks. His company, Bauer Pottery, also had an outdoor line of Redware used in the garden as pots, seed pans, and hanging baskets.
In 1929, the company hired a ceramic engineer to develop new glazes. By 1930, the California Colored Pottery was introduced and the California Ring Line became popular household items. They produced dinner plates, cups, saucers and gravy boats.
The new glaze was uranium-238. This radioactive glaze with a half life of 4.4 billion years is found in the Ringware line that was popular in the 1930’s. By the time war hit in the 40’s, the uranium, tin, copper and lead used to make the pottery was being used up by the war effort as resources. The line struggled through the 50’s, dissolving in 1961 due to labor disputes. The pottery was unique in its time because the rings around the outside made it distinguished and different. Today this line of Ringware is highly collectible. Many of the pieces are not marked, but a Geiger counter can easily tell if the item is radioactive.
Red/Orange combination is the most radioactive of the pieces, and uranium oxide was also added to green, yellow and brown.
Do you remember learning about George Washington and how he had wooden dentures? Apparently, times have changed since then, but not the crazy things used to put into our mouths. Back in the 1950’s and 1960’s, dentures were the rage, along with tie dye and flower freedom.
The porcelain used to make the dentures was nice and shiny because uranium-238 was added to the molding process. Uranium-238 has a half life of 4.4 billion years, while giving off significant alpha and beta particles. The idea was not that your head was getting radiated, but that the teeth would give off a natural shine like real teeth. Studies have been done over the years to determine how much radioactivity would have been absorbed by the oral mucosa from U-238, Th-234, Pa-234m and natural occurring K-40. It was determined that porcelain dentures containing 0.1% of uranium might have delivered a dose of 600 rems per year of alpha particles and 2.8 rems of beta particles.
The United States wasn’t the only country to add uranium for the sake of vanity. Studies have shown dentures high in radioactivity in Japan, England and Greece.
#6 Dinner Plates
One of the most interesting and widely used dinner plates and saucers in the 1930’s and 1940’s was the line of Fiesta Ware. Although it has been documented over and over, it’s always fun to retell this story of how the use of radioactivity was incorporated into dinner plates and bowls.
The manufacturer Homer Laughlin Company created the line of Fiesta Ware. It was introduced at the Pittsburg China and Glass Show in 1936. The line became very popular as a household item due to its durability and bright bold colors. The problem was that the beautiful shine that lasts a lifetime was created by adding uranium oxide to the glaze. That is radioactive uranium-238, with a long half life of 4.4 billion years and an emission of alpha and beta particles.
The original colors were red, blue, ivory, green and yellow. The red series, which technically looks orange to everyone, was the original lot that came off the production line. By 1937, more than one million pieces had been sold to households across America.
This line of products were manufactured for 37 years until production stopped in 1972 and retired the bold colors for a more subdued line fitting the avocado green and almond paste tan popular at that time.
The original line became popular after production stopped due to the levels of radioactivity that are present. The orange plates are highly sought after by collectors still today.
#7 Chewing Gum
In the 1980’s, a fresh mint gum was produced called Check-Up. The gum was marketed as being able to scrape the plaque off teeth as it was being chewed. The ingredient that rubbed against the enamel to scrape that plaque is called zirconium silicate, also referred to as Zircon. This element is found in coastal regions deep in the earth’s crust of the Americas, Australia and South Africa. It is mined then separated as a powder from the other elements.
Trace elements in the Zircon are uranium-238, radium-226, radium-228 and thorium-232. The gum contained 7pCi per gram of uranium and radium. Radium-226 has a half life of 1600 years and uranium-238 is 4.4 billion years. Small amounts of thorium-232 with a half life of 14 billion years and radium-228 with a half life 5.75 years are found in Zircon.
The amount of radium in each piece of gum was significant enough that if it was found in a basement near a soil deposit of radium, it would be wise to have this area treated to remove the radioactivity.
Common table salt is made of sodium chloride. This mixture is needed in our bodies for normal functions, but too much can cause an increase in blood pressure. It has become commonplace to find alternatives to using salt by flavoring food with other ingredients. One of those is a salt substitute. The Cumberland Packaging Corp manufactures Nu-Salt® as a salt substitute. The words salt substitute are used because there is no sodium chloride in this product, it is made of potassium chloride.
Potassium chloride contains the radioactive element potassium-40 or K-40 with a half life of 1.28 billion years. This is a naturally occurring radioactive material that is found in all organic material, including the human body. The ingestion of this type of potassium chloride does not exactly taste like salt, but it is combined with other ingredients to give a salt flavor derived from citrus fruits and honey.
#9 Camping Mantles
In the center of a lantern is a mesh sack that will light with the flame of a match. This mesh is called a mantle and is generally used in the camping industry in lanterns. The mesh is a nylon web material that is framed with a wire to give it a dome shape. The wire is set into a lantern and lit with a fire source to produce light. Fuel is used in the form of kerosene or gas to keep the lantern lit.
During manufacturing, the mesh mantle is dipped in a solution of thorium nitrate, a radioactive material derived from naturally occurring Thorium-232 found in water, rock, soil and plants. When large concentrations are found, it can be mined and used. Thorium-232 has a half life of 14 billion years. When heated in the form of thorium nitrate, an incandescent and long lasting glow comes off the mantle. It was first produced commercially in the 1880’s by an Australian chemist.
Camping is a major industry in the United States. More than half the thorium mined was used by the camping supply companies to dip the mantles for light production. This continued until the Coleman company decided the radioactive by-products, in the form of alpha emission, of the thorium nitrate could be better replaced with a less radioactive luminescent. Around 1990, they replaced the thorium mantles with yttrium oxide which produced less light, but lasted longer. By the year 2000, more than half the mantles produced by the United States still contained thorium nitrate.
In the world of Physics, there is a dice game that simulates radioactive decay. The dice themselves are not radioactive, but the game has die that range from four sided (d4) to one hundred sided (d100). Technically it’s an experiment used in classrooms to teach about radioactive decay in the nuclei.
At one point, and only one reference is available to substantiate this claim, a set of dice was made by using depleted Uranium.
Depleted uranium has less uranium-235 (half life 700 million years) and uranium-234 (half life 245,000 years), but more uranium-238 (half life 4.4 billion years) than its counterparts found in nature. Depleted uranium emits fewer alpha particles than the naturally occurring uranium.
Depleted uranium is heavier than lead by 68%. It is radioactive and should be handled with gloves because the material is soft and easily bendable. Dust like charcoal can be rubbed off and absorbed into the skin.
Back in the 1950’s, or around that time, a set of dice made from depleted uranium was found. It was a set of two six sided dice in the slate gray color. The dice are covered in nickel and on display in Oak Ridge, Tennessee at the Oak Ridge Associated Universities (ORAU) Health Physics Historical Instrumentation Museum Collection.