Science Friday 2021-09-03 Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email Schools And The Delta Variant, Doubts For High-Tech Air Purifiers. Sept 3, 2021, Part 1 COVID Fact Check, Ocean Circulation and Climate, Bread Culture. Sept 3, 2021, Part 2 Produced by Science Friday and WNYC Studios