In addition to the many environmental and culinary reasons why more and more people are growing their own food or buying locally at farmer's markets is food safety. When we know who grew our dinner, or at least when we know that a person in our neighborhood grew it, we have more trust that that person is looking out for our health and welfare.
There's an interesting article on Treehugger today about the growing popularity of farmer's markets (there are 5,000 of them!) in Japan. The author's point rings so true to me: "People are apparently buying [products for sale at farmer's markets] because they feel safer eating products made by farmers who aren't afraid to be identified."
Food safety is surely on all our minds following the news in the last couple of weeks about peanut butter and peanut "paste" products being recalled because of salmonella taint. For a full list of the peanut products that have been recalled, visit this FDA website.