If your Aura of Ruin is capable of breaking apart biological materials, including flesh and organs, then it should also destroy bacteria. As such, food would cease to rot. Disease would also cease to function, as it relies on Bacteria, Virusses, or Rogue Cells.

A poison is a little harder. It's effectively a complex chemical with specific effects on the human anatomy. Breaking it apart would be much like breaking apart water, or sugar. Unless Hale causes materials to seperate into their base materials, his Aura of Ruin shouldn't have any significant effect on poisons.

This raises a number of questions. Can Hale kill people with his mere presence?