22564
Although the study by Foster et al . provides scientifically sound data needed by the US Food and Drug Administration ( FDA ) as it evaluates the safety of these products , we should ask , " Why was it necessary that these chemicals be studied again for their cardiovascular actions in humans ? "
 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