699
This is a cross - sectional study in NHANES 1999 - 2000 participants who were at least 18 years old , including 911 non - Hispanic whites ( NHW ) , 398 non - Hispanic blacks ( NHB ) , and 595 Mexican - Americans ( MA ) .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None