6388
The lead concentrations in the studied samples were found to be in the range of 15 - 61 ng Pb mL - (1) for milk and 21 - 42 ng Pb g - (1) for yoghurt samples .
 Chemical: Pb; 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; Chemical: Pb