4072
The mean concentrations of cadmium and lead in animals aged <= 3 years ( n = 80 ; 1 . 40 +/- 1 . 05 ng / ml and 7 . 91 +/- 3 . 60 ng / ml , respectively ) were lower than in animals aged > 3 years ( n = 58 ; 2 . 69 +/- 1 . 67 ng / ml and 11 . 8 +/- 5 . 71 ng / ml , respectively ) .
 Chemical: cadmium
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: cadmium