12245
Oxidative and nitrosative stress and apoptosis in oral mucosa cells after ex vivo exposure to lead and benzo [ a ] pyrene .
 Chemical: benzo [ a ] pyrene
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