2452
Examining the contamination levels showed that this grey seal population seems more highly exposed to Pb than other phocid populations ( 2 . 2 mg / kg dw of grey seal hair ) .
 Chemical: Pb
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: Pb