A good example is the cancer causing aflatoxin on peanuts. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/cpg-sec-570375-aflatoxins-p

A good example is the cancer causing aflatoxin on peanuts. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/cpg-sec-570375-aflatoxins-peanuts-and-peanut-products https://www.fda.gov/regulatory-information/search-fda-guidan... You could be enjoying some all natural peanuts and be exposing yourself to a highly carcinogenic byproduct of a fungus that grows on them. Hell, people were doing that for millennia until some scientists actually discovered it.