18862
Metabolic Activation of Polycyclic Aromatic Hydrocarbons and Aryl and Heterocyclic Amines by Human Cytochromes P450 2A13 and 2A6 .
 Chemical: Polycyclic Aromatic Hydrocarbons; Chemical: Aryl and Heterocyclic Amines
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Polycyclic Aromatic Hydrocarbons; Chemical: Aryl and Heterocyclic Amines