What's New?
.	HPS and CRCPD Proclaim 8-14 November 2009 as National Radiation Protection Professionals Week
.	November Newsletter
.	NRC Academic Program Nuclear Education Grants, FY2010, Now Accepting Applications
.	November ORS
.	November Journal
.	EPA's STAR Graduate and GRO Undergraduate Fellowship Funding Now Accepting Applications

Upcoming Events
.	2010 HPS Midyear Topical Meeting Radiation Risk Communication to the Public 24-27 January 2010 Albuquerque, NM
.	2010 HPS Professional Development School Radiation Risk Communication: Issues and Solutions 27-29 January 2010 Albuquerque, NM

07 November 2009

Answer to Question #1474 Submitted to "Ask the Experts"

Category: Radiation Effects — Effects on Tissues and Organs

The following question was answered by an expert in the appropriate field:

How do alpha, beta, and gamma rays and neutrons interact with living tissue?

Alpha and beta particles, neutrons, and gamma and x rays are ionizing radiations. That is, they interact with matter (all matter, including living tissues) by ionizing its atoms. An ion is an atom that has become charged by either gaining or losing an electron. For example, alpha particles are positively charged and attract negatively-charged electrons from orbit around atomic nuclei, leaving the atoms with positive charges. Beta particles are negatively charged and do the same by repulsion of like charges. Neutrons and gamma and x rays are electrically neutral, but eject electrons from orbit by collision. The ionized atoms, if contained in biologically vital molecules such as DNA, result in damage that may be permanent or may be repaired by normal mechanisms. If the cell can survive without the damaged molecule, then the result may be no detectable tissue damage. However, the ionized molecule, such as water, may form a free radical and attack important molecules. S. Julian Gibbs, DDS, PhD

Answer posted on 7 December 2001. The information and material posted on this Web site is intended as general reference information only. Specific facts and circumstances may alter the concepts and applications of materials and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice specific to whatever facts and circumstances are presented in any given situation. Answers are correct at the time they are posted on the Web site. Be advised that over time, some requirements could change, new data could be made available, or Internet links could change. For answers that have been posted for several months or longer, please check the current status of the posted information prior to using the responses for specific applications.