Document mp8r7z3R3VnYGYk5z637zOXEb

IONIZING RADIATION proportion of about one nitrogen atom to twenty oxygen, to five carbon, and to fortyfive hydrogen atoms It is therefore impor tant to study the effects of radiation on water and on materials of a composition which resemble human tissue Irradiation of water produces large num bers of free electrons which have been ejected from the parent atoms, leaving posi tive ions In this process of ionization, there is dissociation of the water molecule and the release of oxidizing agents In die human body, there may be changes of struc ture of organic molecules and changes m the biochemical processes. Some of these same changes may he occurring independ ently of the radiation, so the mechanisms are complex and are being studied inten sively Fig 424a Normal cell division > CELLS DAMAGED OR IMCAPABLE OF LIFE Fig. 42-4b. Damage or death of cells fol lowing division of irradiated parent cell. O Reprinted with permission from "Atomic Radiation," O 1957 by RCA Service Co , Inc Types of injuries The accumulation of knowledge of the effects of radiation on man was begun in 1895 when Roentgen discovered the X-ray Radiation from uranium was discovered by Becquerel m 1898 Alpha, beta, and gamma rays were discovered shortly thereafter, and the neutron was discovered in 1930. Injuri ous effects were experienced by these early workers in nuclear science As radiation was applied to man for healing purposes, effects such as skm redness, dermatitis, and skm cancer were noted, as were loss of hair and eye inflammation It was found that the incidence of cancer and of certain blood diseases was higher among radiologists than would be expected for a chance dis tribution in the population studied The pool of health experience data was obtained from (1) early radiation work ers, (2) medical personnel who routinely administered radiation for diagnostic and therapeutic purposes, (3) patients who were treated with radiation, and finally, (4) a group of workers who painted dials with luminous paints containing radium It be came apparent that exposure to ionizing radiation was associated with a higher-thaonormal incidence of certain diseases, such as skin, lung, and other cancers, of bone damage, and of cataracts It appeared also that there was some life shortening Relating dosage to damage Extensive work was done in an attempt 42-10