23654
Subjects consisted of 131 workers in three groups : 40 cases with DA confirmed by a positive specific inhalation challenge ( SIC ) ( DA + ) , 41 exposed workers with lower respiratory symptoms and negative SIC ( DA - ) , and 50 asymptomatic exposed workers ( AWs ) .
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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:
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