Longines radioactivo años 20

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[/FONT] [FONT=&quot]Who are those girls seated at the lower left? They are watch dial painters. Radium, a radioacitve substance, was mixed with other ingredients to create a luminous paint for applying to the dials and hands of clocks and watches, making them glow. In the 1920s, young women, most just out of high school, were employed as dial painters at an East-coast company. Apparently the pay was pretty good. In order to paint neat and sharp numbers on the dials, the girls were encouraged to occasionally "sharpen" the fine brushes by using their lips and teeth to straighten the bristles. Naturally, some of the paint was ingested. No one warned them of any potentional harmful effects. In fact, some girls painted their teeth or applied glowing "makeup" as a novelty to show their friends. In the late 1920s, some dentists began to notice a high incidence of jawbone<o></o>[/FONT]
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[FONT=&quot] deterioration among young women, most of whom had worked at the dial company. Later, cancers of the head and neck, anemias, and other disorders were found, resulting in some early deaths. Clearly the implication was that the radium paint was directly responsible for the illness. The topic still is controversial, and I don't really know the data from a scientific point of view, but my "gut feeling" is that something bad happened here. A book has been written about the subject, "Radium Girls: Women and Industrial Health Reform," by Claudia Clark. Radium has an interesting history: It was hailed as a miracle discovery, and was used in radiotherapy for certain cancers. It made its way into some cure-all potions, and even into radioactive soft drinks! Radium spas existed, where you were supposed to swim in vats of radioactive water, to cure various ills and improve your health. <o></o>[/FONT]
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[FONT=&quot]I have more recently done some more experiments with a dozen or so 1950s Timex wristwatches. More radioactive dials were found, and x-ray pictures created. [/FONT][FONT=&quot]They're beautiful in strange way. Here is the link.[/FONT] [FONT=&quot]<o> </o>[/FONT]


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Flash del Foro Nuclear. Nº 378. 1/III/98.​

Radiation Protection Dosimetry, 72. 49-53. 1997.
Los primeros relojes luminosos en sus esferas, números ó indicadores de horas,
minuteros y segunderos, tenían como activadores de la luminiscencia algunos compuestos
de radio. Desgraciadamente, la impregnación de las mezclas empleadas, llevada a cabo con
pinceles, dio lugar a una ingestión por vía bucal de esta sustancia radiactiva por los
operarios, mujeres en su mayoría, que aguzaban los pinceles humedeciéndolos con la boca.
En los años posteriores a la comprobación de los efectos nocivos de la ingestión se
emplean preferentemente para la iluminación nocturna de los diales de los relojes de
pulsera pinturas activadas por Tritio (isótopo de hidrógeno con semiperíodo de 12,3 años).
La actividad del Tritio en relojes de pulsera metálica fabricados en la India están
entre 5,5 y 18,8 MBq y las tasas de pérdidas de Tritio oscila entre 0,2 y 15 KBq por día en
tiempo húmedo.
Con ello la vida media del Tritio en los relojes es de unos 3 a 7 años, basándonos en
la estimación de la actividad inicial y en la tasa de pérdida media.
La dosis efectiva anual al portador del reloj de pulsera es de unos 0,0025 mSv como
consecuencia de la inhalación del aire respirado y de la absorción por la piel, suponiendo el
caso más desfavorable de la tasa de pérdidas más alta y uso contino del reloj en muñeca.
En la situación peor, la máxima tasa de dosis anual equivalente a la piel estaría entre
6,7 y 67 mSv para una superficie de 10 cm2, lo que en cualquier caso sería muy inferior a​