- The Capital’s air quality deteriorated to the ‘severe’ category on Saturday as thick smog engulfed it preventing the dispersion of pollutants.
- This is the fourth time this season that the air quality in the city has worsened to the ‘severe’ category.
National Air Quality Index
- This index is launched under Swacch Bharat Abhiyan in 2014.
- Aim is ‘one number- one colour-one description’ for the common man to judge the air quality within his vicinity
- There are six AQI categories, namely Good, Satisfactory, Moderately polluted, Poor, Very Poor, and Severe. Each of these categories is decided based on ambient concentration values of air pollutants and their likely health impacts (known as health breakpoints).
- An AQI between100 to 200 comes under the ‘moderate’ category, 201 and 300 is considered ‘poor’, 301 and 400 ‘very poor’, while that between 401 and 500 is ‘severe’.
- AQ sub-index and health breakpoints are evolved for eight pollutants (PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb)
Root Causes of smog and air pollution in Delhi
- One of the main reasons of increasing air pollution levels in Delhi is crop burning by the farmers in these states. Farmers burn rice stubbles in Punjab, Haryana and Uttar Pradesh.
- Pollution caused by the traffic menace in Delhi is another reason contributing to this air pollution and smog. The air quality index has reached ‘severe’ levels.
- As the winter season sets in, dust particles and pollutants in the air become unable to move. Due to stagnant winds, these pollutants get locked in the air and affect weather conditions, resulting in smog.
- Another reason of air-pollution is over-population in the capital. Over-population only adds up to the various types of pollution, whether it is air pollution or noise pollution.
- Industrial pollution and garbage dumps are also increasing air pollution and building-up smog in the air.