18361
Nickel ( Ni ) is a common pollutant found in aquatic environments and may be harmful at elevated concentrations .
 Chemical: Nickel; Chemical: Ni
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: Nickel; Chemical: Ni