12179
METHODS : We evaluated serum levels of IL - 10 in 51 employees working in oil refinery ( group A ) and in 16 office workers who resided in the same area ( group B ) .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None