Doctors call for radon-proof homes to cut cancer deaths

Doctors are calling for a change in the way houses are built to protect against radon gas, which causes 1,000 deaths a year in the UK. Described as the "worst environmental pollutant", radon is colourless and inert, and seeps up from the ground exposing people who breathe it to radiation, which can cause lung cancer.

Doctors are calling for a change in the way houses are built to protect against radon gas, which causes 1,000 deaths a year in the UK. Described as the "worst environmental pollutant", radon is colourless and inert, and seeps up from the ground exposing people who breathe it to radiation, which can cause lung cancer.

For £100, a "radon-proof" damp course can seal the foundations of new homes and help prevent the gas collecting.

Worldwide, radon causes a million deaths every decade and the change could save half of those lives, specialists said.

The largest and most rigorous study of radon, published yesterday, has shown that the gas causes 20,000 deaths from lung cancer in the European Union each year, about 1,000 of which are in the UK.

The research combines the results from 13 studies and shows that smokers are at greatest risk. When radon is inhaled it attaches itself to cells lining the lungs and is especially harmful to smokers, whose cells are already partly damaged.

At the high level of 400 becquerels, radon increases the risk of lung cancer by about two-thirds. On average, four non-smokers in 1,000 will get lung cancer before the age of 75 but that rises to seven in 1,000 among those exposed to 400 becquerels of radon. Among smokers, 100 in 1,000 will get lung cancer before 75, rising to 160 among those exposed to 400 becquerels. The risk for smokers is 25 times higher.

In Britain, most concern about radon has been focused on areas where its levels are highest, such as Devon and Cornwall, where it is difficult to sell a house without a certificate showing the radon level.

The National Radiological Protection Board says where the level is 200 becquerels or more, work should be carried out to seal the underfloor area and install a fan to disperse the gas, at a cost of £1,000.

The new study, published in the online edition of the British Medical Journal, shows that at 200 becquerels the risk of lung cancer is increased by one-third. Professor Sarah Darby of Oxford University, who led the study, said most deaths associated with radon were in houses with lower levels of exposure, because there were more of them. She said: "We found there is a detectable risk even in homes with levels below 200 becquerels per cubic metre. We estimate that about 90 per cent of radon-induced lung cancers occurred in homes with levels of radon below 200 becquerels per cubic metre.

"Over the next few decades one of the most cost-effective ways of reducing the number of lung cancer deaths caused by radon may be for builders to incorporate low-cost radon-proof membranes into the foundations of all new homes, even in areas that are not designated as being particularly radon-affected."

Professor Sir Richard Peto of the university, added: "Radon gas is probably the worst environmental pollutant. Now we have direct evidence of what the dangers are. If only it were blue and people could see it they would take it seriously, but unfortunately it isn't. The main way radon kills is by killing smokers. If they had not smoked in the first place they would not be killed. Even so, changing the building regulations would save a lot of them."

The National Radiological Protection Board said it would review its advice in light of the findings. About 100,000 British homes have radon levels of 200 becquerels, and between 500,000 and 600,000 have levels of 100 becquerels.