1 / 4

less dangerous

Biological Effects of Radiation. nonionizing radiation : bumps e – to higher energy levels or heats molecules; . less dangerous. ionizing radiation : knocks e – out of molecules; . more dangerous. a , b , g , x-rays, high-frequency UV. -- e.g., .

Télécharger la présentation

less dangerous

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.


Presentation Transcript

  1. Biological Effects of Radiation nonionizing radiation: bumps e– to higher energy levels or heats molecules; less dangerous ionizing radiation: knocks e– out of molecules; more dangerous a, b, g, x-rays, high-frequency UV -- e.g.,

  2. H2O+ + H2O H3O+ + OH : : ( O–H) . -- sequence of action in living tissue (1) creates H2O+ (2) neutral free-radical w/unpaired e– The free-radical initiates a number of chemical rxns. that disrupt cell function. -- the tissues most damaged by radiation are the ones with cells that rapidly reproduce: bone marrow, lymph nodes -- low doses over a long time can induce cancer, which is… the uncontrolled reproduction of cells.

  3. “radiation absorbed dose” “roentgen equivalent – man” Units for Radiation Doses 1 bequerel (Bq) = 1 disintegration/sec 1 Curie (Ci) = 3.7 x 1010 disintegrations/sec 1 gray (Gy) = absorbing 1 J/kg of tissue 1 rad = absorbing 1 x 10–2 J/kg of tissue Since the various types of radiation damage tissue with various degrees of efficiency, each type has its own relative biological effectiveness (RBE). photon or b RBE = 1 rem = RBE x rad n0 RBE = 10 a RBE = 20

  4. radon formed this, too, is an a-emitter radon emits a radiation -- estimated to be responsible for ____ of U.S. lung cancer deaths 10% Radon -- an a-emitter from the decay of radium in rocks and soil -- very dense; seeps into basements and is readily inhaled a a Ra-226 Rn-222 Po-218

More Related