8130
For the combined toxic effects of PAHs and heavy metals , cell growth and antioxidant responses varied with exposure time and contaminants and differed between free and immobilized cells .
 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: PAHs 
Answer:
 Chemical: PAHs