2447
The changes in tissue concentrations of 11 elements ( Ca , Cd , Cr , Cu , Fe , Hg , Ni , Pb , Se , V , and Zn ) were investigated in a longitudinal study during the lactation period and during the post - weaning fast period .
 Chemical: Ca; Chemical: Cd; Chemical: Cr; Chemical: Cu; Chemical: Fe; Chemical: Hg; Chemical: Ni; Chemical: Pb; Chemical: Se; Chemical: V; Chemical: Zn
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: Ca; Chemical: Cd; Chemical: Cr; Chemical: Cu; Chemical: Fe; Chemical: Hg; Chemical: Ni; Chemical: Pb; Chemical: Se; Chemical: V; Chemical: Zn