17635
We further explored the interaction between PAH - DNA adducts and placental PAHs with respect to NTD risk .
 Chemical: PAH; Chemical: PAHs
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: PAH, PAHs 
Answer:
 Chemical: PAH; Chemical: PAHs