After few days of 'good' air quality in the national capital, the pollution level has gone up due to local factors, officials said Sunday. The Air Quality Index (AQI) was recorded at 159, over four times more than last Tuesday, according to the Centre's System of Air Quality and Weather Forecasting and Research Institute (SAFAR). An AQI in the range of 0-50 is considered 'good', 51-100 'satisfactory', 101-200 'moderate', 201-300 'poor', 301-400 'very poor' and 401-500 'severe'. A Central Pollution Control Board (CPCB) official said the rise in pollution level is due to local factors especially the vehicular pollution. "After the monsoon subsided, the local reasons resulted in increase of pollution in the city," the official said. According to the data from the CPCB, the PM10 level (presence of particles with diameter less than 10 mm) was recorded as 'moderate' at 171 in Delhi-NCR and 167 in Delhi. The PM2.5 level (presence of particles with diameter less than 2.5 mm) was 81 in Delhi-NCR and 85 in Delhi. The Supreme Court appointed body Environment Pollution Control Authority (EPCA) has called for a meeting next week to explore possible solutions to control local factors responsible for the rise in pollution. According to the SAFAR, the pollution level is expected to further increase in the next two days, specially the PM10 level. Monsoon rain had improved the air quality in the last two months. Since July, the air quality remained 'satisfactory' and even witnessed three days of 'good' category.