![]() They are highly susceptible to radiation injury. The blood-forming cells, located mainly in the bone marrow, are both immature and rapidly-dividing. In particular, cancerous growths in which cells are proliferating rapidly are more radiosensitive than healthy tissue - a fact which contributes to the effectiveness of radiation therapy. It had been demonstrated by 1904 that immature cells and rapidly dividing cells are more sensitive to ionizing radiation than mature cells. By 1940, there were over 100 documented cases of radiation-induced cataracts in humans. Below a certain threshhold dose, however, there seemed to be no noticeable impairment of fertility, perhaps because nature is so prolific in producing sperm and eggs.īy 1904, it was learned that exposing the lens of an animal's eyes to ionizing radiation could produce cataracts. Somewhat lower doses caused temporary sterility in males or a permanent reduction in fertility in females. There were, indeed, other less immediately obvious medical effects resulting from exposure to ionizing radiation.īy 1903, x-rays had been used to permanently sterilize rabbits and guinea pigs of both sexes. More importantly, the concept of radiation safety had not yet been extended to include the more subtle effects of exposure to ionizing radiation. The x-ray film at that time was highly variable in sensitivity, and reddening of skin depended on a great many factors. Throughout this period, there were no units of measurement to allow for quantitative comparisons of dose. Such a "tolerance dose", although 50 times lower than that suggested by Rollins, is still 15 times higher than the maximum permissible exposure for an atomic worker in Canada in 1990. This idea was formalized in a 1925 recommendation (advanced independently by Sievert and Mutscheller) that no more than 1/100 of an erythema dose should be allowed in any 30-day period. It was generally assumed by practitioners that any dose well below that which produced reddening of the skin (the "erythema dose") was safe. Unfortunately, these recommendations never became widely known and were largely ignored. In 1921 the same body published a set of recommendations for radiological protection from x-rays and radium. In 1916, the British Roentgen Society unanimously declared that medical and dental x-ray examinations are hazardous, and recommended a number of precautions. If that criterion were followed today, doses would be allowed which are more than 700 times larger than the maximum permissible exposures set for atomic workers in Canada in 1990. If the plate wasn't fogged after seven minutes, he asserted, then the radiation wasn't harmful. In 1902, Rollins suggested using a photographic plate to measure x-ray or gamma ray doses, anticipating the "film badges" worn by atomic workers today. back to Table of Contents Section A - Section B - Section C Workers preparing the needles, surgeons implanting them, and nurses attending the patients, often received substantial gamma doses. Such a needle, inserted into an unwanted growth, would deliver most of its harmful gamma energy to the diseased tissue, while minimizing the dose to healthy tissue. At about the same time, Marie Curie's hands suffered painful radiation burns after she handled a thin metal box containing a small tube of radium.īefore long, radium-filled "needles" were being used to treat solid tumours. As a result, he got a nasty burn on his chest which ulcerated and left a scar. In 1898, Becquerel carried a sealed tube of radium in his vest pocket. Gamma rays were found to be equally potent. That same year, scientists in several other countries began using x-rays to treat cancer and to relieve arthritic pain. ![]() His was the first recorded therapeutic use of such rays to shrink tumours. ![]() Grubbe decided to focus those same rays on a cancerous tumor, using lead to shield himself from unwanted exposure. In 1896, in Chicago, after painfully injuring his hand with x-rays, W. Surgery was often needed to repair the damage. By 1902, hundreds of cases of x-ray injuries were documented. By 1897, 69 cases of skin damage were reported. Too much x-radiation caused recurrent reddening of the skin or loss of hair, hours or days later, often followed by painful radiation burns. Some of the harmful effects of ionizing radiation were apparent from the outset. Stochastic Effects and the Linear Hypothesis Delayed Effects and the Latency Periodī.27. Relative Biological Effectiveness (RBE)ī.25. Biological Effectiveness of Ionizing Energyī.22. Radium Jaw, Anemia and Septic Infectionsī.19. Early Suggestions for Exposure Standardsī.6. Biological Effects of Ionizing Radiationī.2. Health/Environment Issues Linked to the Nuclear Fuel Chain - Section B Health and Environmental Issuesī.
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