wendyvarro: Notes and queries: Are we all eating irradiated food? What went on underneath the arches? What's the population of heaven?

Are we all eating irradiated food? What went on underneath the arches? What's the population of heaven?

What happened to irradiated food? Are we all eating it without knowing?

A nuclear reactor blows up and everybody panics. The answer to this is almost certainly yes. But irradiating food does not make it radioactive. For this it must contain radioactive elements; the danger is far greater from eating food contaminated with such elements. Radioactive caesium 137, for instance, mimics potassium and thus can be taken up in plants that are later eaten and the radioactivity concentrated by grazing animals.

There has always been a natural level of radioactivity in certain soils ? those on a granite substrate for instance ? but the caesium 137 fallout from Chernobyl is still relatively high in some areas. Just as dangerous, and thought to be the cause of 21,000 lung cancer deaths annually in the US, is the radon gas that accumulates in confined spaces in houses. Tents, anyone?

Terence Hollingworth, Blagnac, France

Here in Germany, I remember reading about a full trainload of radioactive Turkish hazelnuts, found several years after Chernobyl on some far track of a Bundeswehr depot.

More seriously, I guess most low-contaminated food has been mixed up and processed in large-scale industrial food plants in order to keep below (rather high) tolerance levels. And don't forget the nuclear particles in the soil ? they simply follow the natural decay cycle of radioactive material. So, every now and then, you can find warnings about mushrooms collected in the local forests, or about game shot there. So the answer to the question is yes.

Roland Wittig, Freiberg, Germany

What was in the arches of inner-city railway bridges before they filled up with lock-up garages, bars and restaurants?

When London's first railway, the London and Greenwich was planned, the promoters envisaged using most of the 878 arches for dwellings and show houses were constructed at Deptford. Doubtless estate agents, or their equivalents of the time, tried their best to sell with euphemisms such as "handy for trains".

However, the public showed little enthusiasm and after the opening in 1836 most arches were let to commercial undertakings. As a forerunner of today's wine bars there was a public house reached from Rotherhithe New Road called the Halfway House. I don't know if it remains, but as the viaduct was successively widened, railway historian Edwin Course surmised it must be one of the longest pubs in England.

There was also a chapel in one arch, but unused arches created problems ? they were used for refuges and purposes described in contemporary accounts as "immoral", and provided convenient places to conceal bodies of newborn babies. The railway company then sealed off the arches in heavily populated districts.

In the 1970s and 80s, arches under the London Tilbury and Southend, and the Great Eastern, lines in Tower Hamlets were used for small engineering firms and car repairs, among other uses. Many arches were used for taxi maintenance.

When the London to Greenwich 150th anniversary was celebrated in 1986, the former British Rail Property Board promoted the use of arches for start-up businesses. I assume they were successful. As an example of linear commercial development railway arches have proved highly successful, and spared railway operators from the problems of endless level crossings.

Roger Backhouse, Ilford

What is the population of heaven?

Deluded?

David Stokes, Munich, Germany

Nobody is quite sure. But the census forms are even now winging their way back.

David Christmas, Shipston-on-Stour, Warwicks

I received an email last week saying that my message was undeliverable ? but I had sent the email in April 2006! Where has it been for the past five years? How many miles has it covered in cyberspace?

Since cyberspace works in light speed, your mail must have travelled about five light years, and this would have been enough to reach our closest neighbour-stars, Alpha Centauri A and B, if it wasn't trapped in our terrestrial internet-wires.

Li Post, Germany