I imagine that in a competitive market where the participants are educated that the farmers would publish tests alongside their crop and the educated consumer would understand that they should be buying direct from farmers and be processing the turmeric themselves
it's not about education, but rather attention.
how much of your finite attention do you want to spend on extra things? most people already operate under extreme attention-scarcity.
This is why governments exist and what you're proposing is absurd. Do you want to compile a list of every possible threat you are exposed to daily and amend your comment? Sounds like you need to educate yourself on the role of government before you parrot more "competitive market" nonsense.