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The radon levels in some of the mines can reach 400 to 700 kBq m −3. [17] A common unit of exposure of lung tissue to alpha emitters is the working level month (WLM), this is where the human lungs have been exposed for 170 hours (a typical month worth of work for a miner) to air which has 3.7 kBq of 222 Rn (in
The half-life of 147 Pm is only 2.62 years, so in a decade the radioactivity of a promethium dial will decline to only 1/16 of its original value, making it safer to dispose of, compared to radium with its half life of 1600 years. This short half-life meant that the luminosity of promethium dials also dropped by half every 2.62 years, giving ...
The largest natural contributor to public radiation dose is radon, a naturally occurring, radioactive gas found in soil and rock. [10] If the gas is inhaled, some of the radon particles may attach to the inner lining of the lung. These particles continue to decay, emitting alpha particles, which can damage cells in the lung tissue. [11]
Naturally occurring radioactive materials (NORM) and technologically enhanced naturally occurring radioactive materials (TENORM) consist of materials, usually industrial wastes or by-products enriched with radioactive elements found in the environment, such as uranium, thorium and potassium and any of their decay products, such as radium and radon. [1]
Unprotected experiments in the U.S. in 1896 with an early X-ray tube (Crookes tube), when the dangers of radiation were largely unknown.[1]The history of radiation protection begins at the turn of the 19th and 20th centuries with the realization that ionizing radiation from natural and artificial sources can have harmful effects on living organisms.
As Texas baked in record-breaking heat this summer and a growing drought pushed water levels down, a group of volunteers uncovered something sort of magnificent: new giant dinosaur tracks that are ...
Radon is thus assumed to be the second leading cause of lung cancer after smoking, and accounts for 15,000 to 22,000 cancer deaths per year in the US alone. [9] [better source needed] However, the discussion about the opposite experimental results is still going on. [10] About 100,000 Bq/m 3 of radon was found in Stanley Watras's basement in 1984.
A microbiologist is proposing the idea that the reign of dinosaurs forced mammals to speed up their reproductive cycle, eliminating key longevity genes. A Scientist Says Humans Were Meant to Live ...