For example, two years ago, a major recall was issued for millions of pounds of ground beef used in school lunch programs, which serve millions of struggling families. More recently there was a similar, smaller recall of ground beef found to be tainted with e.coli. A study by the USDA's ERS shows that consumption of ground beef is directly related to income level; people of higher incomes tend to consume more food safe whole cuts of beef.
Even vegetables are a higher risk if you're poor: A study by Drexel University showed that produce tended to have a significantly higher proportion of contaminants in higher-poverty areas. In large part, this is due to the retailers: large grocery-store chains have systems in place to support food safety, while smaller corner stores often purchase from questionable suppliers and then do not have the facilities to properly refrigerate their produce.
While officials look at the problems in our food system, we can act quickly by educating those in difficult circumstances about food safety and how to choose safe foods. For instance, providing simple signage on the basic principles of cross-contamination, the temperature danger zone, and proper sanitation in grocery stores could go a long way towards helping lower-income families stay healthy. Educators can look on The Partnership for Food Safety Education's website for curricula on food safety for grades K-12 - while associated largely with the giant agribusinesses - their education information page is excellent.
(*I particularly enjoyed this post, also by Marion Nestle, offering an Agribizspeak-to-English translation of an ad by the "American Egg Farmer.")