I think just about everyone in the natural/alternative and/or Paleo communities is familiar with the issue mentioned by Nance, as well as the various synthetic -ides used on all non-organic produce. Probably the most fundamental alteration of our nutrient sources in the name of hygiene or sanitation is the chlorination (i.e. poisoning) of virtually all urban and suburban water.
However, the sanitation procedure that has received the least attention and thus the least resistance IMO is the widespread irradiation of numerous types of food, at least in the U.S. I was completely unaware of the importance of this issue until I read this article on Dr. Mercola's website: http://articles.mercola.com/sites/articles/archive/2011/11/05/why-are-your-spices--seasonings-exposed-to-half-a-billion-chest-xrays-worth-of-radiation.aspx?e_cid=20111105_DNL_art_3
You don't have to be paranoid about every food you buy because of this, but if you buy foods that are not local or organic, I recommend checking if they have been irradiated, as the FDA requires them to be labeled as such. See the above article for the irradiation symbol.