Scientists have been studying the effects of radiation on the body for over 100 years, so we know quite a bit about how radiation interacts with living tissue. This video takes a closer look at how the amount of radiation our bodies receive, otherwise known as the dose, can affect the cells in our bodies. Other videos focused on possible health effects of radiation emergencies can be found here: http://emergency.cdc.gov/radiation/protectiveactions.asp Comments on this video are allowed in accordance with our comment policy: http://www.cdc.gov/SocialMedia/Tools/CommentPolicy.html This video can also be viewed at http://www.cdc.gov/wcms/videos/low-res/NCEH/2015/biological_effects_of_radiation_922304.mp4