Air Quality Analysis – July 2023

Air Pollution is a big issue in India especially in the Northern part. However, even though the issue is highlighted in the media and lot of steps are announced by the government to curtail air pollution, situation on the ground remain unchanged to a large extent. With the onset of monsoon, the problem takes a back seat as the air quality improves due to favourable weather conditions and the governments start claiming that the improvement is due to their efforts. Driving on a two-wheeler or cycling on roads in Delhi is dangerous even in monsoon period with large amount of road and construction dust which can cause severe impacts. This issue needs to be taken seriously and permanent solutions found so that air quality improves all year round.

Below is a brief representation of data captured by portable devices installed in multiple locations in Korba and Delhi. The analysis has been done for two reporting periods – 1 July to 31 July 2023 and Jan 2022 to July 2023.

Section 1 – Data Analysis for period Jan 2022 to July 2023

Table and Graph above show the Average Monthly AQI in different Cities. The graph and data clearly showcase the winter months when AQI comes under dangerous levels and summer and monsoon months when the air quality is Satisfactory. It is clear that AQI increases with the onset of winter and has started decreasing as summer progresses. With the onset of monsoon, there should be further improvement. This improvement in Air quality is primarily because of favourable weather conditions and not because of any mitigation aspects taken by the industries or government agencies.

• During this period, Delhi recorded the worst AQI in the month of January 2023. Out of 19 months, for 13-months AQI in Delhi was above 100 while Korba had AQI above 100 for 15 months.
• July 2023 Air quality has improved over the previous month figures for Korba while it marginally increased for Delhi.
• Air quality is poorer in Delhi as compared to Korba in July 2023
• The overall data for Korba shows that Korba Air is more polluted than Delhi for longer durations in the year.
• With favourable weather conditions July 2023 AQI has decreased in Korba while it has increased in Delhi as compared to July 2022
• The different colour bands in the graph respond to the AQI categories as stated in the NAAQs (More later in the document)

The above table shows the Monthly Average Heat Index for different cities.

Particulate Matter – Paniculate matter or PM is the amount of dust particles in the air. These particles can be of different types i.e. organic, metallic etc. There are different sizes for these particles. Particles of size 10 micron are called PM 10. Those between size of 2.5 and 10 micron are called PM 2.5. those between 1 and 2.5 micron are labelled as PM1. The smaller the size of the particles, the easier for it to enter the air stream of the body and cause more impact. NAAQS and WHO (Word Health Organisation) have both set limits for amount of such particles in the air for PM 2.5 and PM 10. Below are the limits set. The Indian standard values are much higher than the WHO ADQ standard and need to be revised downwards. There are no standards yet for PM 1 which is considerably more harmful.

Below is the table showing Monthly Average PM 2.5 values in different cities. In none of the months did any of the cities meet the higher Indian standard with Delhi touching the standard only in August 2022. In both Delhi and Korba, the values were more than 4 times the values in some of the months. Only during the monsoon period were the values closer to the standard but were still above. In Delhi count of PM 2.5 particles have increased while they have decreased in Korba in comparison with July 2022.  

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