biological effects of radiation

• what effect does radiation have on cell DNA


  • direct damage
  • indirect damage
• what is indirect damage 


  • occurs when radiation directly damages the DNA causing either single or double stranded breaks
  • breaks in DNA cause disruption to cell replication / duplication
• what is indirect damage


  • occurs when radiation interacts with non critical targets within the cell (usually water)
  • this then produces free radicals which attack other parts of the cell
• describe the deterministic effects of ionising radiation


  • deterministic effects only occur once a threshold of exposure has been exceeded
  • severity of effects increases as the absorbed dose increases
  • radiation doses involved are usually substantial and delivered over a short period of time
  • symptoms include: cataracts, erythema, sterility
• describe the stochastic effects of ionising radiation


  • only a probability of effect occurring (chance process)
  • risk of an effect occurring increases as absorbed dose increases
  • very difficult to detect on a widescale due to low dose exposure
  • symptoms include: cancer and hereditary effects