Once we think of air pollution now we think of cities such as Beijing,india,nepal and other african countries. I spent a week in capital of India and that I could never understand the sun.The degree of air pollution might not be this worse visually in each polluted city. With the evolution of the electric, automation and robot item the degree of contamination has increased exponentially if not by tens of thousands fold than it was in our grandfather era.
In this picture you can see before and after a rain, which has knocked a lot of these chemicals from the atmosphere. And these compounds have adverse health effects.We see that in Western Europe especially London, in 1952, they had the fantastic smog. It was hard to see, but tens of thousands of individuals died.The harmful nano particles in atmosphere not only contains harmful germs but also the byproduct of their technological wastes. And that resulted in legislation. We had the exact issues in Nepal and the problem is worsening daily. So what is air pollution? It's not just chemicals in the air but chemicals that have awful health effects. And since we're breathing it in it's likely to affect our lungs, our heart and may result in increased cancer risks. Where are these compounds coming out of? Well they may be produced naturally. And so we have forest fires and volcanoes that may create these pollutants. But also we've stationary sources, it is possible to consider these as industrial, such as factories,mobile, robot industries, electronics material mill.
And then we've got mobile sources. That would be like automobiles and buses. And so if they're effecting us negatively we call these pollutants.There are various sorts of pollutants I have listed here. Beginning with volatile organic compounds or VOCs. This could be like formaldehyde, gas, anything that's natural and can diffuse into the environment. We've got carbon dioxide, this odorless gas. We've got NOx that's going to be nitric oxide and carbon dioxide. We then have sulfur dioxide generated through the combustion of coal. We then have particulate matter. These are likely to be suspended solids. And then eventually we have compounds like lead. All of these are primary pollutants. That means they are created by the source themselves. But they could combine with other compounds in the air and produce secondary pollutants. So such as NOx can produce nitric oxide. And sulfur dioxide can produce sulfuric acid. And these combined can create acid rain or more commonly acid residue which has enormous impacts on life.
One of those pollutants that we're likely most familiar with is ozone which may be produced through sunlight. And we want nitrogen dioxide to create that. And when we can combine a good deal of these then we have smog. It's most likely the most famous sort of air pollution that you're knowledgeable about. And it's made worse by things like temperature inversions. So you might think how can we control the air pollution around us? Well regulation with the help of local laws is one way to go. The clean air act in the USA managed to reduce pollutants and save lives. And so technology can scrub those pollutants from the air before it's released. We here in nepal we aren't still sure of appropriate technology. Various NOn governmental organization are contributing Nepal a enormous lumpsum of cash but the execution and budgeting is feeble.
Where's the air pollution coming from and What are the resources?
The resources can be stationary, similar to this factory. They might be mobile like each of these cars stuck in traffic. Or it may be natural like a giant forest fire can increase the amount of air pollution. But regardless, how do they affect us? It's through our cardiovascular system. It's just like smoking. You may think of it that way if you would like simple analogus example. It may result in lung disease, cardiovascular disease and increased risks of cancer. And so where can we see these health effects most? It is where we have industrialization. So clearly it will be in places like China, but look over here on Nepal. We've got a enormous quantity of industrialization not established as european ntions but still growing to meet nations demand rather than a great deal of regulations.
We've VOCs, which are volatile organic chemicals. An example could be this gas that's evaporating into the environment. Formaldehyde,If you smell a pine tree, these are VOCs or organic chemicals which are coming off and may result in things like smog. We've got carbon monoxide that's produced naturally through photochemical sources. But it may also be generated through combustion. All these sources produce carbon dioxide. We then have NOx that's going to be nitric oxide and then carbon dioxide. It's this brown gas which contributes to that colour that you see in smog. We then have sulfur dioxide. You've probably smelled that in the event that you've ever been about a coal plant. And you can see here that in the US it will be limited to the East shore generally as we're likely to have more industrialization there. And then we've got particulate matter. These are likely to be little solids. This is from the EPA, which means you may imagine sand as an instance of a particulate. But it's not small enough. And so that is your hair. It's going to be on the order of 50-70 microns. And so we're discussing matters which are smaller than that. Little sediments that as you breathe it in the hairs in your nose and respiratory track don't trap it. It goes into your lungs, and just like smoking, it's stuck there and may result in other kinds of diseases. And then we've got chemicals like lead. We used to add direct to our gas. And there are enormous neurological impacts of lead. Now again these key pollutants can produce secondary pollutants. And thus the nitrogen and the sulfur may cause nitric acid and sulfuric acid. And these contribute to acid rain. It can dissolve statues in this way, but what's more it changes the pH in the entire food web and may impact living systems. And then we've got ozone.
Ozone we've talked about before, if we examine the stratospherethe ozone that's produced naturally is blocking damaging UV rays. But if we proceed down close to the ground it generates a tropospheric ozone, we predict that bad ozone. It's one of the big items that contributes to smog, photochemical smog.You are considering there's a temperature inversion. And thus the heat is inverted. When we have, in this environment, the sun is heating the ground. And so we're going to get the air close to the earth warmer. And so if we look at this gradient it's likely to go from heat at low elevation to cool and cooler atmosphere as we move up. And this gradient will move a good deal of those pollutants up and away from that town or where they're produced. But sometimes due to wind or currents or simply the geography of town you can get what's called an inversion. And so instead what we have is a layer of cooler air near the ground. And so it's inverted. And so as we move up it becomes warmer. And then it becomes cooler after that. So what you're doing is you're trapping those pollutants near the surface of the planet. They can't move up and the can't move away. And then we begin to have chemical reactions happening.
What actually causes Photochemical smog
Photochemical smog is caused by these three things, NOx, VOCs and sunlight. And so if we look at that , nitrogen dioxideand when you have sun what happen is that will break a free oxygen atom away. Now that free oxygen atom can combine with atmospheric oxygen and it can create this ozone. And so what's smog? It's essentially these NOx chemicals and then this ozone. But naturally what is going to happen is that these will move back to nitrogen dioxide and routine tropospheric oxygen. And so again, to make smog we must haven't only NOx and sunlight but we must have these volatile organic compounds also. And so how does this work? We break apart that nitrogen dioxide . So we're generating this nitric oxide. And that will unite with these volatile organic compounds in the air itself. So now what happens is that we create this ozone but it's not spontaneously going to return again. And so how the smog is formed? We must have seen the volatile organic compounds (they change from solid to gas without being in liquid form). We have the nitrogen dioxide as one component. And we must have sunlight. And so places like Los Angeles where all of them come together have a enormous amount of smog.
How can we stop Smog
We stop the total amount of nitrogen dioxide and we avoid the total amount of volatile organic compounds in the air. Now how can we remove air pollution? We do this through legislation. So we have limitations on the quantity of pollutants. And thus the clean air act is most likely the most famous one in 1970. And what they did is they set strict criteria on such pollutants over here. And so in industry you're limited on how a number of these pollutants you may put in the atmosphere. But how can we do that? Technologically we could utilize a catalytic converter. This is basically grabbing onto that carbon dioxide and carbon monoxide that's produced in combustion. We can then use mechanical filters or electrostatic filters such as this. They'll generate a gradient and it grabs on to a few of these pollutants. We can wash the atmosphere. And we could use wet scrubbers also. Whilst the air goes in, the contaminated air goes in, we've got a mist eliminator so there's water and that water will catch on lots of those chemicals. They'll move down into this packaging material and the clean air will go out the other side.
Last words
Air pollution can lead to lung disease, cardiovascular disease and then increased cancer risks. Those chemicals could come naturally or may come stationary or mobile sources. We can control that through the clean air act and regulation and technology. If we consider the pollutants themselves,it's VOx, carbon dioxide, NOx. That produces nitric oxide. We've got sulfur dioxide, particulate matter and things like lead. These acids may result in acid deposition. And the combination of these produces smog that's exacerbated by temperature inversions. And so that's air pollution. It's deadly if we don't regulate it. And I hope that was useful. Please comment about air pollution in your area and let us know was this article useful for you.
