21714
Benzo [ a ] pyrene ( BaP ) is a prototype for studying carcinogenesis of polycyclic aromatic hydrocarbons ( PAHs ) .
 Chemical: Benzo [ a ] pyrene; Chemical: BaP; Chemical: polycyclic aromatic hydrocarbons; Chemical: PAHs
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: Benzo [ a ] pyrene; Chemical: BaP; Chemical: polycyclic aromatic hydrocarbons; Chemical: PAHs