19044
In the present study , we have used salmon embryos whose continuous exposure to waterborne PFOA or PFOS at 100 mu g / L started as freshly fertilized eggs , and lasted for a total of 52 days .
 Chemical: PFOA; Chemical: PFOS
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: PFOA; Chemical: PFOS