23408
In addition , a doubling of hepatic copper levels was seen , and overall metal homeostasis was disturbed , resulting in decreased hepatic selenium , manganese , zinc , and iron .
 copper, selenium, manganese, zinc, iron
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 copper, selenium, manganese, zinc, iron