16106
From 60 ecotoxicological studies , the authors extracted 112 single values to work with ( 25 values in 13 studies for nano - Ag , 17 values in 10 studies for CNTs , 7 values in 7 studies for fullerenes , 34 values in 23 studies for nano - TiO2 , and 29 values in 17 studies for nano - ZnO ) .
 Chemical: Ag; Chemical: fullerenes; Chemical: TiO2; Chemical: ZnO
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: Ag; Chemical: fullerenes; Chemical: TiO2; Chemical: ZnO