AQI Current Affairs - 2020

Peak Hour Pollution flattened due to COVID-19

In Indian big cities, the peak hour pollution in the morning and evening flattened due to the lock down. The lock down imposed in the country to contain the spread of COVID-19 has brought down particulate matter of sizes less than 2.5 microns greatly.

Highlights

The big metropolitans like Chennai, Bengaluru, Mumbai, Kolkata and Hyderabad had evidential reduction of pollution level according to Centre for Science and Environment. The Centre says that the pollution levels in the peak hour has gone down by 60% in several cities.

Delhi

The Delhi Air Quality Index turned to Good from Hazardous. In Delhi, the PM 2.5 concentration levels dropped down by 57%, Nitrogen Dioxide levels dropped down by 64%. According to SAFAR, vehicles contribute to 40% of total particulate pollution in Delhi.

Data from CPCB

According to the Central Pollution Control Board, around 92 cities in the country have recorded pollution level of “Good” from “Satisfactory”.

Air Quality Index

The pollution levels are said to moderate when the AQI is between 100 and 200. It is satisfactory when the AQI is between 50 and 100. The pollution levels is categorized as Good when the AQI is between 0 and 50. The other categories are poor (201-300), very poor (301-400) and severe (401-500).

ICAR report on Stubble Burning

On 4th November, 2019, the ICAR’s Creams Laboratory bulletin stated that there has been reduction of 12% in incidents of Stubble Burning as compared to the same period in 2018.

Highlights of the report

  • There were 31,402 burning events in the three states Punjab, Uttar Pradesh and Haryana as on October 1, 2019
  • The state wise reduction in stubble burning as compared to 2018 is as follows
    • Uttar Pradesh-48.2%
    • Haryana-11.7%
    • Punjab-8.7%
  • The report says that the reduction is mainly due to the launch of Central Scheme “Promotional of Agricultural Mechanization of In-Situ Management of Crop Residue in Punjab, UP and Haryana and NCT of Delhi”. The main purpose of the scheme is to subsidize machinery required.

Delhi

New Delhi is worst affected due to stubble burning in the three states. This year (2019) the Air quality Index of Delhi reached 999. This is the highest recorded AQI of Delhi in its history. According to WHO norms the AQI should be under 100.

Also, the PM 2.5 (Particulate Matter) concentration was more than 80% as against 50% of the normal course.

Western Disturbances

The Stubble burning smoke reaching Delhi is greatly influenced by the Western Disturbances. When these Cyclonic circulation are strong and persistent the smoke deposited in the city decreases.

The disturbances are capable of carrying the smoke far and spread them wide when they are strong. The weakening of these disturbances lately due to global warming is also one of the reasons for the increased stubble smoke in Delhi.