1.1. Air Quality Parameters: Sustainability

So, you have seen those screening parameters. So we go to air. The air so in air, we have only 2 things. So, there is a term called Aerosol. So, normally when we say air, so air is a mixture, air is really the aerosol because aerosol is dispersion. The term aerosol is dispersion of a solid or a liquid in a gas basically; but in our gas here we are interested in is air, okay, in air.

Aerosols are tiny solid or liquid particles that are dispersed in the air. When we refer to air, we are essentially talking about a mixture that contains both these particles (like dust or droplets) and gases. This means that the air we breathe isn't just pure gas; it's actually a combination of different materials suspended in the atmosphere.

Think of aerosols like the mist from a spray bottle. When you spray water, the liquid forms tiny droplets that float in the air. Just like these droplets, aerosols like dust and smoke are floating in the air we breathe every day.

So, here there are 2 components here. One is a solid particulate matter, PM plus whatever is there here, this is really a gas. So there are 2 phases so this is aerosol. When they say aerosol, the reason they say aerosol is when you sample air or when you breathe, your breathing the aerosol, you are not breathing this you are not breathing one of the other okay, you are breathing both.

Air consists of two primary components: solid particles known as particulate matter (PM) and gases. When we breathe, we take in a mix of both these components, which means that our lungs are exposed to a combination of tiny solids and various gases present in the atmosphere. This highlights how connected we are to our environment through the air we inhale.

Imagine you're walking through a busy street. The air is filled with dust, bits of leaves, and gases from car exhaust. Just like you can't separate the sounds of cars from the busy street, in the same way, you can't separate the particles from the gases when you breathe in.

So, but here in atmosphere, the common ambient air, we call it as vapor or gas because and at this condition it naturally exists in the vapor phase, in the gas phase, but vapors can coexist as liquid and gas okay, water for example...there is water vapor.

In the context of air quality, it's essential to differentiate between vapor and gas. Vapors can condense into liquid forms under certain conditions, while gases usually remain in their gaseous state. For example, when water evaporates, it becomes water vapor in the air. Understanding this distinction helps in recognizing how different substances behave in our atmosphere.

Consider a pot of boiling water. As the water heats up, you see steam rising. This steam is water vapor. Once the steam cools down, it makes droplets of water on your kitchen counter. In this way, vapor can turn into liquid, showing how these phases interact.

So when we say the air is polluted, we need some handle on that. We cannot just say air is polluted...the biggest contributor to air pollution is ‘combustion’ that’s the biggest activity where there is something that is converted and an exhaust is released.

Determining whether air is polluted requires understanding specific pollutants, with combustion being a primary source of air pollution. Combustion refers to the process of burning fuels, which releases various pollutants, including nitrogen oxides (NOx), sulfur dioxide (SO2), and particulate matter. Recognizing these sources is crucial for implementing measures to improve air quality.

Think of a campfire. When you burn wood, it creates smoke, releasing pollutants into the air. This is similar to how cars, factories, and other combustion processes release harmful substances, indicating that air can easily become polluted if not managed properly.

There are large number of pollutants that are possible that can be present in the environment...criteria pollutants started, so this I will give you a little bit of history on it.

Monitoring air quality involves keeping track of specific pollutants known as criteria pollutants, which include common substances like carbon monoxide and sulfur dioxide. These are prioritized because they have significant impacts on health and the environment. Historical changes in regulations highlight the importance of continuous monitoring to adapt to emerging pollutants.

Imagine a health check-up where doctors check your blood pressure, cholesterol, and glucose levels - these are your ‘criteria’ for evaluating health. Similarly, regulatory bodies establish criteria pollutants to assess air quality and ensure that it remains within safe limits for human health.

This is the crux of what we call as the, in the discussion what we call as sustainability...should not an isolation, you have sustainability where you have an economic model and we have the environmental the environment, and we have society, all these three have to merge.

Sustainability in air quality management revolves around balancing economic, social, and environmental factors. It emphasizes that regulations must not hinder economic activities and must also consider social needs. Sustainable solutions look for ways to minimize pollution while allowing economic growth and maintaining public health.

Consider a city that wants to introduce stricter pollution controls on factories. If these regulations are too harsh, factories might shut down, leading to job losses. The sustainable approach would involve finding a middle ground that allows factories to operate while minimizing emissions, supporting both the economy and community health.

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