BBC NEWS Americas Africa Europe Middle East South Asia Asia Pacific
BBCi NEWS   SPORT   WEATHER   WORLD SERVICE   A-Z INDEX     

BBC News World Edition
 You are in: Health: Medical notes  
News Front Page
Africa
Americas
Asia-Pacific
Europe
Middle East
South Asia
UK
Business
Entertainment
Science/Nature
Technology
Health
Medical notes
-------------
Talking Point
-------------
Country Profiles
In Depth
-------------
Programmes
-------------
BBC Sport
BBC Weather
SERVICES
-------------
EDITIONS
Monday, 28 June, 1999, 14:35 GMT 15:35 UK
Radon
Pie chart of radiation exposures
Most of your exposure to radiation comes from radon
Our bodies are constantly exposed to radiation from a variety of natural sources. This natural background radiation is in the food we eat, it is in the soil, and reaches us from the stars via cosmic rays.

But the single biggest source of radiation in our lives is radon gas, which seeps into people's homes from radioactive rocks buried deep underground.

A man test for radon
A test will establish the concentration of radon in the home
For most UK residents, radon will account for a half of their total annual radiation dosage.

Even so, this represents very little risk: the dosage is well within the safety limits set by the International Committee on Radiological Protection. But in some parts of the country radon levels are raised because of the local geological conditions.

It has been estimated that 50,000 people in Cornwall, Northamptonshire, Derbyshire and Scotland have higher than average concentrations of radon in their homes.

Lung cancer

Radon is seen as a silent threat: you cannot see, hear, feel or taste it. It is formed when atoms of uranium-238 decay. Radon will also decay, and, if it is inhaled, will emit alpha particles that can damage the internal lung surfaces.

A man closes a vent
Special vents can be built for radon
The alpha radiation dislodges the electrons that hold DNA together. This can trigger a series of chemical changes in the body that lead to cancer. Although the human cells are very good at repairing this damage, they cannot cope with high doses of radiation.

The radon concentration in the average UK home is about 20 becquerels per cubic metre. Action to deal with the problem is recommended when the concentration reaches 200 becquerels per cubic metre.

The most effective way to deal with radon is to fit an air pump to a property to vent the gas into the atmosphere. The pumps costs a few hundred pounds and are covered by local council grant schemes.

The dangers of radon became very apparent after World War Two when large uranium mines were opened around the world to feed the nuclear industry. Miners became exposed to high levels of radon and suffered increased rates of lung cancer.

In the big mines in the USA, the lung complaints caused by radon were referred to as "mountain sickness".

See also:

Internet links:


The BBC is not responsible for the content of external internet sites

Top Medical notes stories now:

Links to more Medical notes stories are at the foot of the page.


E-mail this story to a friend

Links to more Medical notes stories

© BBC ^^ Back to top

News Front Page | Africa | Americas | Asia-Pacific | Europe | Middle East |
South Asia | UK | Business | Entertainment | Science/Nature |
Technology | Health | Talking Point | Country Profiles | In Depth |
Programmes