I am sure that most people are not aware that some of the consumer products that are present around us contain radioactive materials (RAM) (ie uranium).

I am posting this, not to scare the public, but to increase their awareness of what common consumer products contain this RAM. Also, this is to inform you that radiation has many uses in our daily lives.

Take a look at the images below and see if you recognize them if they are present in your homes.

Chewing gum

Check-Up Gum helped fight plaque. As the gum was chewed, tiny granules of zirconium silicate (the third ingredient on the list) cleaned the teeth.

The reason Check Up Gum appears here is that the zirconium silicate contained high levels of uranium and thorium (eg, 100 pCi/g). The amount of zirconium silicate in the rubber was such that the uranium concentration was about 7 pCi per gram of rubber. Since the uranium series is in secular equilibrium, the gum also contains 7 pCi of Ra-226 per gram. As a matter of interest, there have been many situations where this level of radium in the ground has required corrective action.

Although Check·Up Gum is no longer produced, zirconium silicate continues to be used in toothpastes and some toothpastes. However, consumers can be assured that the radiation dose is negligible: the radioactive material is bound to the zirconium silicate and would not be assimilated even if swallowed.

Tape dispenser

This is a 3M Scotch Decor Model C-15 Tape Dispenser. It is slightly radioactive due to the thorium-containing monazite sand that was used as ballast. This particular example came from a 55-gallon drum of tape dispensers that the US Army was about to dispose of as radioactive waste.

jewels

As a result of an investigation conducted in early 1988 by the Los Angeles County Department of Health, several state radiation control programs in the US issued warnings about making and wearing jewelry made from old watch parts. . These parts often included radioluminescent dials and clock hands. The jewelry, which included brooches, bracelets, earrings, etc. it had become quite popular and because it was easy to produce, the typical maker was a small business operating out of someone’s home or apartment. Production is known to have occurred in California, Oregon, Texas, and Pennsylvania. Radiation monitoring programs in Tennessee, Texas, and possibly a few other states invited the public to bring suspicious jewelry into their offices to monitor for radioactivity.

The usual way of manufacturing was to take the old watches apart, clean the parts with some kind of abrasive, polish the parts, mount the jewels and possibly coat them with an acrylic spray. It seems that there was no awareness on the part of the manufacturers of the potential dangers.

Although some of the jewelry was worn in direct skin contact and several facilities were found to be contaminated (eg, up to 50,000 cpm), there were no reports of injuries to people who wore or made the jewelry. However, one individual, who had been making such jewelry for six years, was found to have “1/30th of a body charge of radium-226”.

Potassium Chloride Water Softening Salt

Hard water contains more minerals, especially calcium and magnesium, than ordinary water. This can lead to scale buildup in pipes and appliances. A water softener is used to reduce the concentration of these minerals.

In essence, a water softener consists of an ion exchange resin that removes minerals as the water flows through it. After a while, the resin becomes saturated with these minerals and no longer works. At this point, a salt solution is added to the resin. The salt exchanges with the accumulated minerals and allows them to be washed out of the softener into a drain. This rejuvenates the softener.

A variety of materials can be used as the water softening salt, for example sodium chloride (NaCl) or potassium chloride (KCl). In the example shown here, the water softener salt is over 99% potassium chloride.

All potassium contains potassium-40, a naturally occurring beta gamma emitter, and in large enough amounts it is easily detected with a simple measuring meter. This bag, for example, could not pass through a monitor at a nuclear power plant without triggering an alarm.

Smoke detectors

The ion chamber smoke detector was invented in the early 1940s in Switzerland and introduced to the US in 1951.

The sensitive component of the ICSD is an ionization chamber that is open to the atmosphere (photo below left). A radioactive source inside the chamber emits radiation that ionizes the air in the chamber and makes it conductive.

Ion chamber smoke detectors almost always use alpha emitters as a source due to the high ionization density they produce.

Most ICSDs sold today use an oxide of americium-241 (Am-241) as the radioactive source. Typical activity in a modern residential ICSD is about 1 uCi, while activity in one used in public and commercial buildings can be as high as 50 uCi. In 1980, the average activity used in a residential smoke detector was about 3 uCi, three times higher than today.

Am-241 is an alpha emitter, but it also emits a low energy gamma ray (59.5 keV). Am-241 is mixed with gold and incorporated into a sandwich composed of gold and silver foil. The source is 3 to 5mm in diameter and is crimped or soldered into place inside the chamber.

Other nuclides have also been used. NRC records indicate that approximately 124,000 ICSDs were sold between 1971 and 1986 that used nickel-63 (Ni-63). These units averaged approximately 10 microcuries of Ni-63 each.

Radium-226 (radium sulfate) was the first radioactive source used in smoke detectors. According to NUREG/CP-0001, US manufacturers stopped making smoke detectors containing Ra-226 in 1963 when they switched to Am-241. However, based on NCRP 95, it would appear that radium-containing ICSDs continued to be sold in the US until at least 1978. A typical residential smoke detector contained 0.05 uCi of Ra-226, but some contained as much as 0.1 icu. Commercial smoke detectors used considerably higher activities.