For anyone wanting more details on stainless steel and teflon there's a short video on this from nutrition facts (so references the relevant research):

https://nutritionfacts.org/video/stainless-steel-or-cast-iro...

Part of a series of three which includes aluminium:

http://nutritionfacts.org/video/are-aluminum-pots-bottles-an...

and Melamine dishes and Polymide utensils:

http://nutritionfacts.org/video/are-melamine-dishes-and-poly...

Referencing what others have said, it also mentions the Dupont cover up over Teflon, so personally I'm always sceptical of whatever the current advice is, because how long will it be before something surfaces to contadict it etc.???