As Mr Blair is so concerned about our health I would like to point out the importance of decent housing.

10% of privately rented accomodation in the UK is unfit for human habitation

I've seen private accomodation in London that is beyond belief.

One million children in the UK live in housing that is overcrowded or unhealthy

Shelter's leaflet

Temporary accomodation

My local council has to pay on average £240 a week for a double room in a B&B, some of these B&B are definitely substandard (I knew a lady who through no real fault of her own had to live for a while in one of those places and within a week her hands were covered in scabies, she was also terrified as she could not lock her door properly).
Everybody knows that many of these places are not acceptable and still so much of the taxpayers money is used to pay for this poor short term solution that benefits no one besides the owners of these places.

Bad housing does affect people's health and their view of themselves, I think the social cost is huge and as usual some people are making money on other's people misery.
But that's obviously ok.