In every DIY store and gardening centre you will find a weed-killer called Roundup. According to an article in the current edition of the Soil Association's magazine 'Living Earth', one of Roundup's advocates declared at a recent interview that it was "safe enough to drink", that is until he was offered a cup of it to drink. At that point he said, "I'm not stupid" and refused to touch it.
Roundup contains a chemical called glyphosate, which the World Health Organisation's International Agency for Research on Cancer has declared to be "probably carcinogenic to humans". In spite of that the UK's Chemicals Regulation Directorate reports that glyphosate is one of the most commonly found residues in British food. Most cereal crops are sprayed with it just before harvest, and as a result it frequently turns up in our bread. This seems to me to be one good reason for making one's own bread at home using organically grown bread flour.
It takes less than 10 minutes of work to make a loaf using a bread-making machine such as the £45 Morphy Richards Fastbake that we use twice a week. (Second-hand ones are widely available for around £30 on Ebay.) Using 'Doves Farm' organic strong white bread flour, available from Sainsbury's or Tescos at £1.33 per kilogram, some fast acting dried yeast, a little olive oil and dried milk powder, salt and water, a very nice 2lb loaf can be made for around 55p. My brother-in-law kept asking for more when he stayed with us recently.
Home-made bread is also free from all the other preservatives and artificial materials that are used in making bread commercially, so a choice between shop bread and home-made organic bread is not exactly difficult. There's simply no contest.