Locals warned not to use water for baths as authorities urgently check for radioactive or toxic substances.
The Russian president's trip on Wednesday coincided with a marked improvement in levels of pollution, they claim.
Yet nickel capital Norilsk - the city with the highest industrial emissions - does not feature in the top ten.
Krasnoyarsk's skies have been black since the start of the New Year, with locals complaining of 'chemical smell', lack of oxygen.
Krasnoyarsk and Novosibirsk suffering smoke pollution and infernos rage in forests after hot, dry weather.
Residents complain of 'severe carbon monoxide poisoning' as satellite images show blanket of smoke across eastern Siberia.
Waste threatens 11,000 people in Pervomaisk after 'violation of safety rules’.
Does a spooky event in New England 238 years ago hold the clue to the eerie blackness that descended one week ago in Siberia?