grime vs pollutant

grime

noun
  • Dirt, grease, soot, etc. that is ingrained and difficult to remove. 

  • A genre of urban music that emerged in London, England, in the early 2000s, primarily a development of UK garage, dancehall, and hip hop. 

verb
  • To begrime; to cake with dirt. 

pollutant

noun
  • A foreign substance that makes something dirty, or impure, especially waste from human activities. 

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