That's a great point. In the USA the FDA mandates what is acceptable in moderation, individually. There is a maximum dose of a known poison that is considered "ok". The powers at be allow food companies to Micro Poison the public.
A good example is in 2012 big-ag started spraying wheat and oat with glyphosate to improve yield. Glyphosate is, by any available metric, a biohazard. Glyphosate is "ok" in small quantities (-- which by the way it has been measured in consumer food products to be orders of magnitude higher than allowed 100% of the time --). But my point is that each serving of bread will contain the maximum allowable dose. So if you eat 2 servings - you got 2x the dose. That's how the USA calculates it.
A good example is in 2012 big-ag started spraying wheat and oat with glyphosate to improve yield. Glyphosate is, by any available metric, a biohazard. Glyphosate is "ok" in small quantities (-- which by the way it has been measured in consumer food products to be orders of magnitude higher than allowed 100% of the time --). But my point is that each serving of bread will contain the maximum allowable dose. So if you eat 2 servings - you got 2x the dose. That's how the USA calculates it.