Historical clue formulations

• Noxious atmosphere — 2026-02-01
• Oppressive atmosphere — 2020-01-09
• Foul atmosphere — 2018-05-30
• Foreboding atmosphere — 2017-04-02
• Unpleasant atmosphere — 2015-08-12
• Corrupting atmosphere — 2012-09-23
• Noxious atmosphere — 2010-06-06
• Corrupting influence — 2009-01-10
• Poisonous atmosphere — 2008-05-26
• Bad atmosphere — 2008-04-01
• Noxious emanation — 2003-11-05
• Bad atmosphere — 2001-08-31
• Disagreeable air — 2000-06-06
• Air around a fen — 1999-05-26
• Bad atmosphere — 1998-10-10
• Poisonous atmosphere — 1997-04-08
• Noxious gas — 1996-10-22
• Effluvium — 1994-04-29