Food security is a problem that affects not just farmers in 3rd world countries, but our own families right here in the USA. The FDA issues approximately 3,000 recalls each year, costing over 77 billion dollars in economic damage each year. Contaminated food causes more than 3,000 deaths each year.
Spoilage
Salmonella
Undeclared allergens
Unapproved drugs
Microbial contamination
http://www.fda.gov/Safety/Recalls/ArchiveRecalls/2013/default.htm?Page=2