26504
Pilot study on levels of perfluorooctane sulfonic acid ( PFOS ) and perfluorooctanoic acid ( PFOA ) in selected foodstuffs and human milk from Italy .
 perfluorooctane sulfonic acid, PFOS, perfluorooctanoic acid, PFOA
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 perfluorooctane sulfonic acid, PFOS, perfluorooctanoic acid, PFOA