5936
Wistar rats were randomly categorized into 8 groups ( n = 6 ) : 1 control group , 3 groups exposed to fine particulate matters ( PM ( 2 . 5 ) ) alone at 3 doses ( 0 . 2 , 0 . 8 , or 3 . 2 mg / rat ) , 1 group to ozone ( 0 . 81 ppm ) alone and 3 groups to ozone plus PM ( 2 . 5 ) at 3 doses ( 0 . 2 , 0 . 8 , or 3 . 2 mg / rat ) .
 Chemical: ozone; Chemical: ozone
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: ozone; Chemical: ozone