Paints radium

At one time, women painted clock and watch dials with luminous radium paint that was a mixture of radium salts and zinc sulfide. They would place the small brushes between their lips and tongue to make the bristles more pointed, in order to paint fine lines with the radium paint. Over the years, they developed cancers that resulted in badly eaten-away and disfigured lips and jaws. Once the danger was known, luminous radium paint was banned for this use. Today, promethium (Pm-147), with a half-life of 2.4 years, is used for this purpose. 

Radium was once used in paint that was applied on the hands and numbers of clocks and watches. The visible radiation it emitted made it possible to read the numbers in the dark. But the radiation proved very harmitil to the people who applied the radium paint to the ratches and clocks. 

The technique that the painters used included making a sharp point on their brushes by twirling the brush between their lips. They then dipped the bmsh into radioactive radium paint. The dipping and twirling sequence ultimately caused the painters to get a lot of radium on their lips. This resulted in many cases of lip and... 

Radium paint was used for lighting things without using electricity, especially aircraft and ships instruments, emergency signage, and watches. (SSPL/The Image Works)... 

It is well known that the risk of acquiring many diseases is directly related to occupation. Some examples of disease hazards related to occupation include the development of bone cancers among workers who applied radium paint to watch dials and hands, the occurrence of lead poisoning in battery workers, bladder cancers in aniline dye workers and lung cancers in miners of radioactive ores. 

Entrepreneurs wasted no time in finding other commercial applications for tadium. Mixed with zinc sulphide, it produced a phosphorescent substance that was used to make luminous watch faces and aircraft instrumentation. Since radium dissipated stadc chai in surrounding air, it also reduced sparks, which made it useful in factories where flammable vapours could be ignited. Public f ination with the new wonder substance created a market for commercial applications of more dubious utility. Radium paint was used to create glow-in-the-daik slipper buttons, roulette wheels, and fish bait, and farmers were sold radioactive manures that had waste products fiom radium refineries mixed into them. 

Phosphorescent pigments are used in military appHcations, plastics, and paints. Zinc sulfide doped with Ag" (blue) cations, or with Cu" (green) cations are important pigments for the production of color television screens. Phosphorescent sulfide pigments are produced in the United States by Radium Corp. and by Conrad Precision Ind., Inc. 

Around the beginning of this century, cancer and illness was associated with excessive use of X-rays. Watch dial painters got mouth cancer from radium in the paint. It soon was realized that radiation has health effects. The measures of energy deposition concepts introduced... 

Other uses are to produce phosphorescence and fluorescence in organic compounds and for scintillation screens on instruments used to detect radiation. Radium salts were used in the past to paint the dials of luminous clock faces that glow in the dark. 

The women at Radium Dial sometimes painted their teeth and faces and then turned off the lights for a laugh. 

Blood levels of thorium following oral exposure of humans to simulated radium dial paint demonstrated that approximately 0.02% of the ingested amount was absorbed by the gastrointestinal tract (Maletskos et al. 1969). This study was the basis for the ICRP (1979) recommendation of an oral absorption factor of 0.02% for thorium. 

There is no information on the lethal effects of radium due to acute oral exposure. Many deaths, especially from bone cancer, have occurred in humans following long-term oral exposure to radium-226 and radium-228. As described by Rowland et al. (1978), female radium dial painters in the 1920s who "tipped" their paint brushes with their lips or tongues ingested radium in the process. The dial paint usually contained long-lived radium-226 and shorter-lived radium-228. A toxicity ratio has been developed for these isotopes it has been estimated that radium-228 is about 2.5 times as effective,... 

In Great Britain, radium dial painters with higher total radium-226 intakes and who were younger than 30 years of age at the start of painting showed an excess of breast cancers (Baverstock and Papworth 1989). External gamma ray exposure to the radioactive paint could also have been the cause of cancer in this population. 

Absorption, Distribution, Metabolism, and Excretion. Quantitative data on the absorption of radium after intake via any exposure route are very limited. No data were located on the absorption of radium after dermal exposure. Information on laboratory workers exposed to radium during an industrial accident indicates that absorption can occur via the inhalation route. A study in elderly human subjects indicated that at least 20% of the ingested radium-224 in mock radium dial paint was absorbed and retained. No studies were located on the absorption of radium by animals after inhalation or dermal exposure. A study of orally exposed rats indicated that retention of radium at 400 to 500 days was 1% to 7% of the administered dose. Further studies to investigate the absorption and retention of radium after inhalation, oral, and dermal exposure would be helpful in elucidating the relative risks associated with exposure by each route. 

Until the 1960s, radium was a component of the luminous paints used for watch and clock dials, instrument panels in airplanes, military instruments, and compasses (Blaufox 1988). 

Polednak AP, Stehney AF, Rowland RE. 1978. Mortality among women first employed before 1930 in the U.S. radium dial-painting industry A group ascertained from employment lists. Am J Epidemiol 107 179-195. 

In the 1920s, women working in a New Jersey factory painted watch faces with an element called radium that glowed in the dark. The women constantly straightened their paintbrush bristles between their lips to keep them pointed enough to draw the tiny numbers. A few years later, the women began to have strange sores, pains all... 

Figure 4.4 "The Radium Girls" were women in 1920s New Jersey who painted watch faces with radium, an element that glows in the dark. Because the women were in constant contact with the radioactive element, they experienced numerous health problems years later. Some even died because of radiation poisoning.

A second radionuclide to which humans are likely to be exposed is radium, Ra. Occupational exposure to radium is known to have caused cancers in humans, most tragically in the cases of a number of young women who were exposed to radium because of their employment in painting luminescent radium-containing paint on the dials of watches, clocks, and instruments.9 These workers would touch their tongues with the very fine brushes used for the radioactive paint in order to point the brushes. Many eventually developed bone cancer and died from this malady. 

This paint glowed in the dark, because it contained radium (atomic number 88), which is... 

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