> Is it absorbed into the lettuce/does it make it to the consumer? I don't know. If it did, would it be harmful at that dose? Probably not, but I don't know. Does it accumulate in the body over time, to an eventual harmful dose? Don't know. But those questions all demonstrate that it's not simply an irrational fear; there is a good number of questions to answer to go from "this could be unsafe" to "this is definitely safe".

These are all questions that have simple, well-tested, easily-Googelable answers. The fact that you don't personally know them is irrelevant, because scientists and government regulators do.