All gases from the ground have to be viewed seriously, although carbon dioxide is so ubiquitous it is often a red herring.
Carbon dioxide has killed people going down shafts such as at Carsington reservoir. Who is to say what constitutes a confined space? Any dwelling or other enclosure can easily become one.
The cost of preventive measures is not large if planned and carried out during construction.
Similar considerations apply to radon gas, which several parts of the country have lived with for years. If knowledge is there and costs are small, then risk should be mitigated.
It might be a good idea if more domestic floors were reverted to suspended construction, and in flood prone areas they should be on short columns or stilts.
Ventilation in buildings is the big issue. The Health and Safety at Work limits for carbon dioxide are surprisingly low.
If they mean anything, surely it is worth taking the simple steps for assisting/venting gas out of the ground and ensuring it does not migrate upwards into the building, except in the extreme cases mentioned in the article which are perplexing (clay soil, no landfill).
Cannon is quite wrong about the 1 in 80 chance of dying in any year - that is what could be called 'means hiding extremes'.
You are most at risk as an infant, then again as you grow older. In the UK the chance of dying between the age of 15 and 55 is remarkably small and for perhaps unlikely reasons - road accidents being one.
And as for misspending of national resources, this is minimal and for a good cause, especially compared with many other 'leaks' of government money - not least providing at great cost for bats in cavities which were artificially made in the first place and should have been filled up safely years ago (GE News, July).
JE Gray, Warwickshire