Visibility dropped sharply as dense fog and toxic air gripped Delhi, with AQI nearing 500. GRAP-IV curbs were enforced as flights, traffic and court hearings were affectedVisibility dropped sharply as dense fog and toxic air gripped Delhi, with AQI nearing 500. GRAP-IV curbs were enforced as flights, traffic and court hearings were affected Latest News [ SOBAN NEWS: International and National ]