I have to disagree with this. My husband is a health policy researcher, and we've talked about this very topic. Yes, some horrible things are introduced into our food supply through modern farming practices, but the modern food supply is much safer than it was "back in the good old days" when people all grew their own food. Lots more children survive into adulthood now, for instance. Much of that is attributable to modern food safety practices.
When I worked for the EPA, I'd often talk to people who believe that the world today is so much dirtier and more polluted than it was 50 years ago, but that's simply not true. Because of the business regulations that we have, the world is actually becoming cleaner and cleaner. We hear a lot about pollution and food poisoning on the news, so it's in the forefront of our minds and it seems very dire, but if you look at the actual data, things are not as bad as many people believe and are much better than in our grandparents' time.
That's not to say there isn't room for improvement, and certainly animals being kept in crowded and unsanitary conditions is not considered "best practices." But no matter where your food comes from, your garden, your chicken coop, or the grocery store, proper food sanitation practices are necessary to keep your family safe. I grow a lot of our food here. I have a huge garden, I can and freeze foods, we have eggs and meat chickens, and beef animals. But you'd better believe that we wash produce and don't cross-contaminate with raw meat, and I only use university-proven canning recipes, never random recipes from the internet. And I check with university extension when I'm not sure about things like fermented pickles (which have recently been linked to listeria since lots more people are into fermenting things). Food safety is important no matter where the food comes from, and that holds even for organic foods. There is no better organic fertilizer than manure, and all manure is a possible contaminant.
