Delhi's Air Quality Status Report After Diwali is 'Very Poor': 10 Points

NEW DELHI: Delhi woke up on Friday morning to a thick, toxic haze after a night of fireworks to celebrate Diwali despite ban ordered on their sales by the Supreme Court. Air pollution was 18 times the healthy limit in some places and residents complained of eyes watering and aggravated coughs as levels of PM 2.5, tiny particulate matter that reaches deep into the lungs, rose alarmingly. The national capital ranks among the world's most polluted cities.

  An index of air quality or AQI was way above 300 on Friday and some parts of Delhi such as Mandir Marg showed an air quality reading of 941, close to the maximum level of 999 beyond which no readings are available. The index measures concentrations of PM 2.5, PM 10, ozone, nitrogen dioxide and sulphur dioxide among other indicators.                                                        

        An AQI from 0-50 is considered good, 51-100 is satisfactory, 101-200 is moderate, 201-300 is poor, 301-400 is very poor, and 401 and above is severe. PM 2.5 and PM10 are micro particles suspended in the air that cause smog and haziness and make it difficult to breathe when levels are elevated. The permissible level of PM 2.5 is 60µg/m³ while PM10 is 100 µg/m³.  

     AQI of above 300 is "hazardous" the most severe level on a U.S. embassy scale of measurement. A hazardous level is an alert in which everyone may experience ill effects and are advised to stay indoors.