16330
Approaches employed in the present study can be extended to other environments to characterize Hg contamination in aquatic systems and Hg exposure risks in top predators .
 Chemical: Hg; Chemical: Hg
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: Hg, Hg 
Answer:
 Chemical: Hg; Chemical: Hg