New Delhi, Oct. 25 -- Delhi-NCR is facing a double environmental blow, with toxic white foam reappearing on the Yamuna River near Kalindi Kunj and air quality across the region slipping into the 'unhealthy' category, with the overall Air Quality Index (AQI) touching 168.

PM2.5 and PM10 continue to be the dominant pollutants. Monitoring stations across the city showed local variations, with readings as low as around 110 at PGDAV College, Sriniwaspuri, while several other stations recorded levels between 118 and over 180.

The deterioration had prompted the Commission for Air Quality Management (CAQM) to invoke Stage 1 of the Graded Response Action Plan (GRAP) across Delhi-NCR on October 21 to curb air pollution.

Under GRAP-1, the use of ...