Background Radiation Limits

average annual background radiation UK

2.2mSv

annual effective dose limit for public

1mSv

annual effective dose limit radiation worker

20mSv

Exposure to radiation depends on

absorbed dose

type of radiation

body organs/tissue exposed

stopping ionising radiation

whenever radiation passes through a medium some of the energy is absorbed

stopping alpha radiation

range in air - 20cm

absorbed by - paper sheet

absorbing beta radiation

range in air - few metres

absorbed by - 2/3cm aluminium

absorbing gamma radiation

range in air - /

absorbed by 2/3cm lead