18155
Mean concentrations of BFRs were higher in pine needles ( 79 . 8 ng / g dry wt ) than in eucalyptus leaves ( 74 . 5 ng / g ) , whereas an inverse result was found for the leaf surface particles , with mean concentrations of 3490 ng / g and 5718 ng / g , respectively .
 None
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:  
Answer:
 None