Qualité de l’air à Ajmer

Is the air quality in Ajmer heavily polluted?

Ajmer is a city located in the Indian state of Rajasthan, in the northern region of the country. It is known as one of the eldest cities within the state, and has a great level of importance historically speaking, as well as being selected as both a heritage city and future smart city by the Indian government’s smart city mission.

Looking at the levels of US AQI on record in Ajmer, it can be seen that in May of 2021, a reading of 50 was taken in the early hours of the day. This indicates a ‘good’ level of air quality as per the air quality ratings bracket, and whilst this represents a period of time in which the air would be free from large clouds of smoke, haze and hazardous particulate matter, it is not truly indicative of the pollution levels typically present within Ajmer.

Looking back at past readings of US AQI taken over both April and May, one can see that the readings were considerably higher, showing that although they can sink down to more appreciable levels during certain times of the day, they can also shoot back up rapidly. Other higher readings on record include numbers such as 116, 118 and 125, all of which sat in the ‘unhealthy for sensitive groups bracket’, and even higher readings of 153, 156 and 170, all of which were within the ‘unhealthy’ air quality ratings bracket.

In terms of its yearly average, Ajmer came in with a PM2.5 reading of 39.8 μg/m³ over the course of 2020, placing it in 78^th place out of all cities ranked in India, as well as 199^th place out of all cities ranked worldwide.

What causes poor air quality conditions within Ajmer?

The main sources of polluted air within Ajmer are ones that typically have some form of combustion taking place. This can take place within vehicle engines, factory boilers as well as the burning of raw organic materials in low income districts and rural areas. These clouds of smoke generated by the fires in people’s houses can drift many miles over to nearby cities and permeate the atmosphere there, causing the PM2.5 count to shoot up rapidly. These fires are usually fed by materials such as dried animal dung, charcoal and firewood, all of which can release a myriad of chemical compounds and harmful particulate matter when combusted.

Other prominent forms of air pollution include ones such as meteorological sources, with dust or sand clouds generated often causing the particulate matter count to shoot up. In closing, vehicle exhaust fumes, factory emissions, construction sites, the burning of raw materials as well as the open burning of trash and refuse can all come together to see the compounded levels of air pollution on record in Ajmer.

When is Ajmer at its most polluted?

Observing the air quality data collected over 2020, one can see that the first three months of the year, as well as the last three months, were all the ones with the highest levels of air pollution present. January through to March presented with PM2.5 readings of 40.7 μg/m³, 47.6 μg/m³ and 41.9 μg/m³, all of which sat within the ‘unhealthy for sensitive groups’ bracket.

October through to December presented with readings of 53.8 μg/m³, 49.7 μg/m³ and 47.7 μg/m³. This demonstrated that October was the most polluted month of the year with its reading of 53.8 μg/m³, being only a few units away from moving up to the next air pollution ratings bracket, that of the ‘unhealthy’ one, which requires a much higher PM2.5 reading of anywhere between 55.5 to 150.4 μg/m³ for classification.

When is Ajmer at its least polluted?

The months in which Ajmer has its lowest level of air pollution are typically seen in the middle portion of the year, and this is once again demonstrated by the PM2.5 levels on record in 2020. The months of April through to September all had the lowest readings of pollution, with five months coming in with a moderate reading, with the exception of May which still sat within the unhealthy for sensitive groups bracket. Attaining a moderate ranking of air quality requires a reading anywhere between 12.1 to 35.4 μg/m³ to be classed as such.

The readings between April and September were 30.2 μg/m³, 41.6 μg/m³, 34.6 μg/m³, 30.1 μg/m³, 27.4 μg/m³ and 32.5 μg/m³ respectively, so with the exception of May as mentioned, all came in below 35.4 μg/m³. The cleanest and most pollution free (relatively speaking) month of the year was August with its reading of 27.4 μg/m³, a common occurrence in many cities throughout India, which is essentially to have a good reading of air quality in both August and September before the pollution levels start to climb rapidly again.

What are some of the air pollutants found in Ajmer?

Besides the chemical compounds used to calculate the overall level of US AQI, there are many other pollutants found within the atmosphere in Ajmer, sometimes changing drastically depending on the area, due to the variety of different materials undergoing combustion (for example certain factories will release a multitude of different chemical compounds as a byproduct of their manufacturing process, plastic production plants will leak burnt plastic fumes as well as microplastics, and metal processing plants can leave behind heavy or toxic metals in the surrounding environment).

Other pollutants that would have some prevalence would be ones such as black carbon, which is the main component of soot, and a potent carcinogen when inhaled. As well as this, it can go down to incredibly small sizes, belonging to the ultrafine material collective and being counted in the PM2.5 bracket. Other pollutants include volatile organic compounds (VOCs), which along with black carbon, find their release from the incomplete or poor quality combustion of fossil fuels, as well as organic materials such as wood, dead plant fibers and charcoal.

Some examples of VOCs commonly found are ones such as xylene, toluene, methylene chloride and formaldehyde, all of which have highly dangerous effects on one’s health, as well as maintaining a gaseous state even at lower temperatures. Other pollutants include particulate matter such as finely ground gravel and silica, sand particles and other ultrafine materials that are created within the city, or blown in via strong winds from rural areas or nearby cities. Some further one’s worth mentioning are the heavy metals such as mercury, lead and cadmium, as well as dioxins, furans, and polycyclic aromatic hydrocarbons.