Watches, radium paint

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. 

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. 

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... 

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). 

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. 

The name comes from the Latin radius, meaning ray. It was discovered by Marie and Pierre Curie in 1898 when they were studying uranium and other radioactive materials found in pitchblende. There is about 1 g of radium in 7 tons of pitchblende, but it is 3xl05 times more radioactive than uranium. It was isolated as a metallic element in 1911 by Marie Curie and Andre-Louis Debieme (1874-1949). Radium exists in small quantities associated with uranium ores. Radium is phosphorescent, so it has been used to make luminous paint, especially for watch dials, but, because it is highly radioactive, most uses are related to nuclear medicine or the energy industry. Radon gas is produced from radium and is a harmful by-product. 

After the war-time demand had ceased, other applications of the paint were made and quickly became popular. Now, in addition to watch and clock dials, luminous paint is used to mark street signs, door plates, push buttons, or almost anything that may need to be located in the dark. The amount of radium used in this manner has been enough to cause serious concern in regard to the future supply, but the largest use of radium at present is in treating cancer. 

Before radiums dangerous radioactive properties were understood, it was used to make paints for watches and clocks that could be seen in the dark. Currently, radium is used in medical facilities like hospitals and other treatment centers to produce a radioactive gas called radon, which is used to treat cancer patients. 

The laborers who painted the watch faces had particularly delicate work to do. The tiny numbers required a perfect tip on the brush, and it was a common practice to lick the tip to make it paint just right. This went on all day long every day of work, so workers consumed radium-infused paint at a steady rate—for years in many cases. Many of the workers, who were mostly women, eventually developed bone cancer, particularly of the jaw. 

An awful fate befell many of the young women hired to paint radium onto the dials of watches, so that they would glow in the dark. The original luminous watches had been designed for soldiers fighting in the trenches during the First World War, but their novelty stimulated a... 

USE Pigment For paints, oilcloths, linoleum, leather, dental ruhber, etc., especially in the form of lithopone mixed with ZnO as "mineral white. Anhydr zinc sulfide is used in x-ray screens and with a trace of a radium or mesothorium salt In luminous dials of watches, etc. also television screens. 

Few commercial uses exist for the radioactive decay products of uranium. The highly radiotoxic Ra was used in luminous paint on watch and instrument dials and, during the 1920s and 1930s, was also widely used in radiotherapy to treat tumors as well as therapy for diabetes, sciatica, uremia, rheumatism, and even impotence (Genet 1998). The radium decay product, Rn, with its half-life of 3.8 days is still used, after sealing it in minute tubes called seeds or needles, for local irradiations in patients. 

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