18156
For most of the BFRs , the correlations between their concentrations in plants and those in the vapor phase , atmospheric particles , leaf surface particles , and the environmental variables ( temperature , wind speed , and relative humidity ) at this site were in contrast to the results the authors observed at an electronic waste site previously , indicating that ambient air level plays a vital role in the relationships .
 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