Every day we read about something new that is out there in the food supply trying to kill us. The miracles of modern farming and food preservation means that mass produced substances move from market to table astonishingly fast. Even when problems are discovered it is often too late to prevent harm. If you ever get a chance to visit a food factory, whether it be a cannery, egg farm, or slaughter house, you'll see what I mean. There simply aren't enough humans available to inspect every item that is produced and packaged.
I'm not naive enough to believe that we should stop producing food this way. I'm a farm girl after all. Mass production means cheaper, and yes, more reliable goods are available for everyone. If everything was "hand reared" no one would be able to afford to buy it.
Growing your own food and preserving it has it's own risks too. The neighborhood cats, rats, dogs, birds, and even toddlers can contribute body-borne pathogens to your soil, e. coli being the tamest bug you can get. Then there is the helpful home canner who unwittingly serves botulism as the first course. It's a dangerous world.
But the good thing, in my opinion, is at least I have some measure of control over the food I ingest. I know where the cats like to spray, know how much to rot a pile of chicken manure, know how to wash my own pesticide free vegetables, know how to spot a bad jar of home canning.