20122
The mechanisms that can account for the remarkable mammary carcinogenicity of the environmental pollutant 6 - nitrochrysene ( 6 - NC ) in the rat remain elusive .
 6 - nitrochrysene, 6 - NC
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 6 - nitrochrysene, 6 - NC