1590
A Mann - Whitney U test revealed significant difference in beta - HCH levels ( U = 1237 . 00 , W = 4087 . 00 , z = - 6 . 296 , p = 0 . 000 , r = - 0 . 71 ) , dieldrin levels ( U = 1449 . 00 , W = 4299 . 00 , z = - 5 . 809 , p = 0 . 000 , r = - 0 . 68 ) and pp ' - DDE levels ( U = 2062 . 00 , W = 4912 . 00 , z = - 2 . 698 , p = 0 . 007 , r = - 0 . 59 ) between AD patients and controls .
 Chemical: beta - HCH; Chemical: dieldrin; Chemical: pp ' - DDE
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: beta - HCH; Chemical: dieldrin; Chemical: pp ' - DDE