Delhi's air quality remained in the 'poor' category zone for the second consecutive day today. According to the System of Air Quality and Weather Forecasting and Research (SAFAR), the city's air quality index was 254 at around 10 this morning.<br />''<span style="color: #222222;"><br />''An AQI between 201 and 300 is considered 'poor', 301-400 'very poor' and 401-500 'severe'. </span><br />