Delhi's air quality remains in the 'very poor' category amidst a cold wave and dense fog, with several monitoring stations recording hazardous levels. The average AQI reached 346, with 27 out of 38 stations reporting 'very poor' conditions. Transport emissions, industrial activity, and residential sources are identified as primary contributors to the pollution. Air quality is expected to persist in the 'very poor' range until January 13 due to cold and calm weather.