Dose Calculator

Personal Annual Radiation Dose absorbed from the environment

We live in a radioactive world, and radiation has always been around us as a part of our natural environment.

The annual background radiation is about 3 mSv, including 2.4 mSv of nature radiation and 0.6 mSv of man-made radiation. The annual background radiation may vary in different geographical environment. International Commission on Radiological Protection (ICRP) study also pointed out that the majority of people around the world are exposed to environmental radiation in the range of 1 to 10 mSv each year.

It is not uncommon for any of us to receive more than that in a given year (largely due to medical procedures such as x-ray). Consequently, to protect health and safety, the Radiation Ordinance (Cap. 303), Laws of Hong Kong, requires that doses received by worker who are employed to undertake any work involving exposure to ionising radiation are limited to 20 mSv in a year and that doses received by members of the public are limited to 1 mSv in a year.

You may input information related to your daily life and the calculator will estimate your annual effective radiation dose absorbed. (If you have no data to input to a particular field, please leave it blank.)


1. Cosmic radiation (from outer space) depends on the elevation level above

the peak,    mid level,    sea level

Cosmic radiation comes from outer space. The sun also contributes a small amount of the radiation and there are about 500,000 cosmic rays enter our body every hour. The atmosphere protects us from the cosmic radiation. Since the atmosphere gets thinner the higher up we go, the radiation dose will increase with altitude. As Hong Kong does not have high mountain range (the highest Tai Mo Shan is only 957 meters height) and most of the densely populated areas are at sea level, therefore, altitude does not have much impact on us.

2. Soil is radioactive. Environmental radiation dose released from the ground will depend on local geological composition and duration stay.

Provide the daily hour in the following location(s) which you normally stay:

Hong Kong Island Hour(s)
Kowloon Hour(s)
New Territories East Hour(s)
New Territories West Hour(s)
New Territories North Hour(s)
Lantau Island Hour(s)

Select types of building you live

wooden building
concrete and brick building

Building materials in Hong Kong are mostly concrete and brick which with release radon gas. The annual effective dose for living in these buildings is about 0.93 mSv.

Ingestion sources from food and air
(0.6 mSv)

Number of brazil nuts eaten in a month

(0.0042 mSv per 100g and normally a brazil nut weight 3.5g and will have 0.000147 Sv)

Number of bananas eaten in a month

(0.00008 mSv per 100g, normally a banana weight 200g and will have 0.00016 mSv)

Number of litres of beer drank in a month

(0.000001 mSv per liter)

Number of cigarettes smoked in a month

(0.00004 mSv per cigarette)

Number of return trips by jet plane annually:

Hong Kong to Taipei and return
Hong Kong to Bangkok and return
Hong Kong to Tokyo and return
Hong Kong to Beijing and return
Hong Kong to Sydney and return
Hong Kong to London and return
Hong Kong to Vancouver and return
Hong Kong to New York and return

Numbers of chest x-ray in a year

Numbers of CT Scan (head) in a year

Numbers of CT Scan (chest) in a year

Numbers of CT Scan (abdomen) in a year

Have porcelain crowns or false teeth

Use gas lantern mantles when camping

Wear a luminous wristwatch (LCD)

Luggage inspection (typical x-ray machine) at airports

Install a Smoke Detector

Wear a plutonium-powered cardiac pacemaker

Annual Total Dose: (0 mSv)      

Remarks: The dose calculation programme is prepared and disseminated in the interest of promoting the exchange of information. The HK SAR Government (including its officers and employees) makes no warranty, statement or representation, expressed or implied, with respect to accuracy, completeness, or usefulness of the information contained herein, and in so far permitted by law, shall not have any legal liability or responsibility (including liability for negligence) for any loss, damage, or injury (including death) which may result, whether directly or indirectly, from the supply or use of such information.