aflatoxin: a potent carcinogen from the fungus Aspergillus; can be produced and stored for use as a bioweapon
mycotoxin: a toxin produced by a fungus
significant digit: any digit of a number that is known with certainty; any digit of a number beginning with the leftmost non-zero digit and ending with the rightmost non-zero digit (or a zero considered to be the exact value)