New Delhi, Oct 22 : The air quality in the national Capital dipped to 'very poor' quality as the overall Air Quality Index (AQI) of the city reached 302 on Sunday morning, according to data from the System of Air Quality and Weather Forecasting And Research (SAFAR). The AQI at Dhirpur entered into a severe category with PM 2.5 at 337, under a very poor category. Experts said that the air quality may remain in a very poor category on Monday. The AQI between zero and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe'. In Pusa, the AQI recorded PM 2.5 at 232 'poor category'. At Lodhi Road, the Air Quality Index with PM 2.5 concentration was at 232 under the poor category and the PM 10 stood at 161 also under the moderate category. At IIT Delhi station the PM 2.5 was at 283, poor category while the PM 10 reached 165, in moderatecategory. The Air Quality Index at the city's Mathura Road was under poor category with PM 2.5 at 215 with PM 10 concentration at 206. According to the forecast from the SAFAR, the air quality of the city will deteriorate further under the very poor category with PM 2.5 reaching 311 and the PM 10 concentration at 210 under poor category' on Monday. The Air Quality Index of Delhi's neighbouring cities of Noida stood at 273 and the PM 10 concentration at 268 both under poor category, while Gurugram's AQI was reported at 186 and the PM 10 concentration at 162 under moderate category. Meanwhile, Graded Response Action Plan (GRAP)- stage-II has been invoked in Delhi and its peripherals as air quality dipped into 'very poor' category, owing to unfavourable meteorological and climate conditions, said the Commission for Air Quality Management (CAQM) on Saturday. A senior official said that the CAQM Sub-Committee for operationalisation of GRAP accordingly took stock of air quality scenarios and air quality forecasts for Delhi made available by IMD/ IITM at the meeting held on Saturday. The Sub-Committee decides to invoke 11-point action plan as per Stage-II of GRAP in the entire NCR in view of Delhi's average AQI likely to reach the projected levels of Stage-II of GRAP on October 23 and October 24 as per the dynamic model and weather/ meteorological forecast provided by IMD / IITM. 'All actions as envisaged under Stage-II of the revised GRAP -- 'very poor' air quality, be implemented in right earnest by all the agencies concerned in NCR with immediate effect, in addition to all Stage-I actions of GRAP already in force,' read the order. The Sub-Committee also urged citizens to adhere to the Citizen Charter under GRAP and assist in effective implementation of the GRAP measures aimed towards sustaining and improving the air quality in the region. They further urged to minimise use of personal vehicles and opt for public transport. The CAQM further said to strictly implement the schedule for regulated operations of DG sets across all sectors in the NCR, including Industrial, Commercial, Residential and offices, etc. It further said to augment CNG/ electric bus and metro services, additional fleet will be inducted and the frequency of service increased. 'Resident Welfare Associations must necessarily provide electric heaters to security staff to avoid open Bio-Mass and MSW burning during winters,' it added. /IANS