New Delhi, Oct 28 (PTI) The Sub-Committee on Graded Response Action Plan (GRAP) on Thursday directed authorities in Delhi-NCR to stop the use of diesel generator sets and increase the frequency of bus and metro services as air quality in the region remained "poor" for the second consecutive day.According to the Ministry of Earth Sciences air quality forecast agency SAFAR, the share of stubble burning in Delhi"s PM2.5 pollution rose to 19 percent on Thursday, the highest this season so far.The air quality in the capital is likely to slip into the "very poor" zone by Friday, it said.On Thursday, Delhi recorded a 24-hour average air quality index (AQI) of 268, Faridabad 274, Ghaziabad 290, Greater Noida 275, Gurgaon 182 and Noida 267.At a review meeting of the sub-committee, Dr. V K Soni from the India Meteorological Department informed that North-Westerly winds will continue until the morning of November 1 and may push the air quality to the "very poor" category.The minimum temperature is likely to drop to 14-15 degrees Celsius with increased moisture, which is unfavourable for dispersion of pollutants, he said.Considering this, the sub-committee asked authorities in Delhi-NCR to implement measures under the "very poor" category in addition to steps listed under "poor" to "moderate" AQI category under GRAP."Mechanical/vacuum-based sweeping of roads to be carried out daily. Ensure water sprinkling along with use of dust suppressants on roads to arrest road dust especially at hotspots, heavy traffic corridors, vulnerable areas (before peak hours) and proper disposal of dust collected in designated sites/landfills," the order issued by the sub-committee read.Regular inspection for strict enforcement of dust control measures must be ensured at construction sites and uninterrupted power supply be provided to discourage the use of generator sets, it said."Stop use of diesel generator sets [except for emergency purposes, enhance parking fee by 3-4 times and increase bus and metro services by augmenting contract buses and increasing frequency," it said.The sub-committee also directed states to ensure that hotels and open eateries do not use coal or firewood.The Graded Response Action Plan -- a set of anti-pollution measures followed in Delhi and its vicinity according to the severity of the situation – comes into force in mid-October when air pollution levels in the region start worsening.Notified by the Ministry of Environment and Forests in 2017, the measures under GRAP include increasing bus and metro services, hiking parking fees and stopping use of diesel generator sets when the air quality turns "very poor".When the situation turns "severe", GRAP recommends closure of brick kilns, stone crushers and hot mix plants, sprinkling of water, frequent mechanised cleaning of roads and maximising power generation from natural gas.The measures to be followed in the "emergency" situation include stopping entry of trucks in Delhi, ban on construction activities and introduction of the odd-even car rationing scheme. PTI GVS TDS TDS