One part per trillion is 1 postage stamp in the area of the city of Dallas 1 inch in 16 million miles (more than 600 times around the earth) 1 second in 320 centuries 1 flea on 360 million elephants 1 grain of sugar in an Olympic sized pool 1 bad apple in 2 billion barrels Mistretta USFS R-8One part per trillion is • 1 postage stamp in the area of the city of Dallas • 1 inch in 16 million miles (more than 600 times around the earth) • 1 second in 320 centuries • 1 flea on 360 million elephants • 1 grain of sugar in an Olympic sized pool • 1 bad apple in 2 billion barrels Mistretta USFS R-8