Antimatter

Bananas release ~1 positron every 75 minutes because of a small amount of Potassium-40, a naturally occuring isotope. As potassium-40 decays, it occasionally spits out a positron in the process. (from symmetrymagazine.org/ten-things-about-antimatter)

But the amount of energy from anhilation of single positron is so less that we don't get to see a bang.

• Humans also have Potassium-40 isotope, and thus we too emit positrons.