New Delhi:
The level of air pollution in Delhi is becoming dangerous every day. On Monday, the air quality in Delhi was so bad that the average AQI was recorded at 494. This was the data of Central Pollution Control Board (CPCB). This is the second worst figure since 2015. At the same time, the international app IQAir on Monday reported Delhi’s AQI to be more than 1,600. A situation of confusion arose regarding this. The question also began to arise that which of the two readings is correct? You will be surprised to know that the readings of both CPCB and IQAir regarding Air Quality Index are correct. Let us understand how:-
Delhi’s AQI was 494, but why did IQAir show it as 1600?
Actually, all countries have different standards for measuring air quality index. This may vary from country to country depending on the pollutants and their measurement scale. For example, the scale of PM 2.5 in India is 60 micrograms per cubic meter. Whereas in some countries that have adopted the standards of the World Health Organization (WHO), this scale can be 5 or 10 or 15 micrograms per cubic meter.
Delhi became a gas chamber due to pollution, AQI reached 500, know how difficult the next 5 days will be.
Similarly, India’s AQI has been capped at 500. But, this does not mean at all that there cannot be more than 500 pollutants in the air. Or AQI cannot go above 500. According to CPCB, an AQI between 0 and 50 is considered good. An AQI between 51 and 100 is considered fair. An AQI between 101 and 200 is considered moderate, while an AQI between 201 and 300 is poor. An AQI between 301 and 400 is considered severe. At the same time, AQI between 401 and 450 is considered very serious and above 450 to 500 is considered very serious.
On Monday, when the hearing on the issue of pollution was going on in the Supreme Court in Delhi, the AQI of the court room was 900. But Indian agencies were showing that AQI has reached 500.
How do international agencies measure pollution in India?
International agencies have installed sensors at some places in many areas of Delhi-NCR. But, are they installed in the right place? Is standard equipment installed? Not much information about this is publicly available.
Breathing Delhi’s air is equivalent to smoking 50 cigarettes, expert told – how to avoid poisonous air
Which reading of AQI should be followed?
However, there is no exact formula to measure pollution. In India, people trust only the data released by CPCB. CPCB has set up 40 stations to assess pollution in the Delhi-NCR area, from where pollution data is collected. Therefore, Indian citizens should consider only the AQI issued by the Central Pollution Control Board as final.
GRAP-4 implemented in Delhi
In view of the increasing pollution, the Commission for Air Quality Management (CAQM) has implemented the fourth phase of the modified Graded Response Action Plan (GRAP) in Delhi-NCR from November 18. Along with this, children, elderly, respiratory and heart patients and those suffering from chronic diseases have been advised to stay at home. Under GRAP-4, all types of construction work will remain closed. Schools up to class 12th have also been closed. Online classes are going on.
NDTV Info Story: Just look at AQI of Delhi, you will be breathless
