emission vs leakage

emission

noun
  • Something which is emitted or sent out; issue. 

  • The act of emitting; the act of sending forth or putting into circulation. 

  • A show; a program. 

leakage

noun
  • An act of leaking, or something that leaks. 

  • The situation where sound is picked up by a microphone from a source other than that which is intended. 

  • The loss of revenue generated by tourism to the economies of other countries. 

  • The amount lost due to a leak. 

  • Loss of retail stock, especially due to theft. 

  • An undesirable flow of electric current through insulation. 

How often have the words emission and leakage occurred in a corpus of books? (source: Google Ngram Viewer )