Smog, air pollution in the whole town. Its make-up changes over time. The word comes from the words “smoke” and “fog,” but it’s usually used to talk about the cloud of pollution from cars or factories that hangs over many towns.
Smog can be broken down into at least two different types: photochemical smog and sulfurous smog. A lot of sulfur dioxide are released into the air when sulfur-containing fossil fuels, like coal, are burned. This is what causes sulfurous smog, which is also known as “London smog.” For this kind of smog to get worse, it needs to be damp and have a lot of floating particles in the air. Smog-like air pollution that gets stuck higher in the sky can stay there as dark clouds, which can have effects on the weather and on people’s health.
Smog in Los Angeles
The most noticeable cases of photochemical smog, which is also called “Los Angeles smog,” are found in cities with lots of cars. It doesn’t need fog or smoke. This kind of smog comes from nitrogen oxides and methane vapors that are released by cars and other things. These gases then go through photochemical processes in the lower atmosphere. There is a very dangerous gas called ozone that is made when nitrogen oxides react with hydrocarbon vapors in sunlight. Nitrogen oxides also react with sunlight to make nitrogen dioxide. The resulting smog turns the air a light brown color, makes it harder to see, hurts plants, irritates the eyes, and makes it hard to breathe. If the amount of ozone at the surface stays above 70 parts per billion for eight hours or more, it’s considered dangerous. This happens a lot in cities that get photochemical smog.
The Big Smog in London
Normal smog filled the city of London for five days, from December 5 to December 9, 1952. It was called the “Great Smog of London.” It was caused by smog from factories and weather conditions with a lot of pressure. London almost came to a stop because of the smoke and fog, which killed thousands. The effects of it led Parliament to pass the Clean Air Act four years later. This was a major turning point in the history of environmental activism.
“London fog” has been around for a long time, long before the crisis of the early 1950s. Such thick, yellow fogs were common in London by the 19th century. They were called “pea-soupers” because they covered the whole city. But London had trouble with dirty air as early as the 1300s because people were burning coal, and the problem got worse as the city grew. In the 1600s, people complained more about smog and smoke, so King James I passed laws that limited coal burning, but they didn’t work. Things got even worse when industry grew quickly starting in the late 1700s.
A dark cloud in Asia
The Asian brown cloud is a big brown cloud that forms over eastern China and southern Asia every year from about November to May. The Asian brown cloud is caused by a lot of aerosols, like soot and dust, that are released when fossil fuels and biomass are burned in the area. For example, since 1930, it has been linked to less summer monsoon rain in India, the summer monsoon moving southward in eastern China, less farming output, and more respiratory and cardiovascular problems among the people who live there.
In the late 1990s, the first records of this event were made as part of the Indian Ocean Experiment (INDOEX). Together, satellites, planes, ships, land stations, and balloons measured air pollution in the Indian Ocean. Researchers were surprised to see a big cloud of aerosols over most of South Asia and the northern Indian Ocean from the INDOEX images. India and China are at least 6 percent less bright at the top now than they were before industrialization. This is because of the Asian brown cloud.
Smog in the Winter
The way people heat their homes with wood changes with the seasons and the weather. So, the amounts of pollution from wood smoke change. In some areas, the way homes are heated in the winter makes it more likely for wood smoke to be produced. This, along with the temperature and the landforms in the area, changes the air quality in these areas.
The weather
In the winter, the air can become full of PM, VOCs, CO, and NOx, which are all byproducts of failed burning. How bad the resulting winter smog is depending on how spread out the pollution is in the air. The more winter smog there is, the less the air can spread the pollution. Wind speed and mixing height are the main things that determine atmospheric spread.
1. The speed of the wind moves the pollution across the ground. When there is no wind, the air stays still, which lets pollution build up, causing smog.
2. The mixing height is the highest point that the toxins can get if they are spread out vertically. Most of the time, the mixing height is high enough to get the pollution high into the air. Particulates are carried to the cooler air higher up by the warm air rising.
Because of the temperature difference, the toxins stay at ground level, where they do the most damage. This kind of inversion can happen before a warm front or in a broad surface rise, for example. The layer of warm air that works as a lid traps cold air below it. The toxins in the lower layer can’t move around, so they stay gathered at ground level.
Geography
Where pollutants are concentrated is also affected by the land’s shape. For example, the “walls” of a valley make it hard for air to move through the valley. There are too many pollutants in the air to spread them out evenly, so towns in the valley will be covered in smog. This problem won’t happen in a town that is on an open plain. Smog can also form in places with a lot of rolling hills, where cold air can get stuck in the hills’ many areas and cause a temperature inversion.
Effects on Health
Smog and its parts can have serious effects on health, which rely on a lot of factors. If you breathe in smog, it can make you sick. How bad it is depending on how much you breathe in, the chemicals it contains, your age, weight, level of exercise, and health. Studies, on the other hand, show that any exposure to these pollutants is bad, but longer exposure and bigger doses clearly do the most damage.
Some affects that smoke has are:
• Itchy eyes, nose, and throat
• Lungs that don’t work as well
• Getting lung or heart problems worse
• In some cases, death
Pollutants and their health effects
This is particulate matter (PM): PM is made up of solid and liquid bits that are different sizes and types. Most of it stays in the nose and throat and doesn’t get to the lungs.[2] That being said, “respirable PM” refers to smaller particles that can get into the lungs. These tiny bits can get deep into things and hurt them. PM does the most damage to the heart and lungs, which can lead to infections, asthma, bronchitis, emphysema, black lung, and other health problems.
Ozone (O3) is a very strong allergen that is also a health risk. It can hurt your eyes, nose, throat, and lungs. It causes breathing problems like coughing and wheeze and can make lungs work less well. It takes a few days for irritated cells to be replaced, but it’s not a perfect process. Long-term effects and constant contact may cause the lungs to age.
Nitrogen oxides (NOx): NOx hurts your lungs and makes you less resistant to illness. It does this both directly and indirectly. Coughing and shortness of breath can happen after even a short time of contact. On a more indirect level, it helps make O3 and PM.
• Sulfur dioxide (SOx): SO2 can irritate the eyes, make it hard to breathe, and make it harder for the lungs to work properly. It can get deep into the lungs and turns into sulfuric acid when mixed with water, which the body can’t handle. It is also one of the main things that causes small PM to form.
• Carbon monoxide (CO): CO is a particle in the air that can hurt your health and kill you quickly in high amounts. It binds to haemoglobin in the blood, making it less able to carry oxygen. This keeps oxygen from getting to cells that need it. High CO levels are worst for people whose immune systems aren’t strong or who have had health problems in the past.
Effects on the Environment
Not only does smog affect people’s lives, it also has a big effect on the environments around us. Ozone and PM in particular are bad for you.
Plant cells can be hurt by ozone, which slows their growth and makes them take in less carbon dioxide during photosynthesis. Because of this, food outputs are lower for all kinds of crops. It can also break down manmade materials like rubber, cotton, and other things, even if they are not made of metal.
Particulate matter suffocates plants, keeping them from getting enough sunlight and stopping them from taking in carbon dioxide. This makes photosynthesis less effective. The chemicals that make up the PM may also have an effect on the plants and the dirt around them. There is smoke in the air because of particulate matter, which makes things less clear and colorful. The hazy look is also caused by the humidity of the air around it. In some places of the United States, the U.S. Environmental Protection Agency says vision drops from 144 kilometers to about 30 kilometers.
Air quality index (AQI)
The air quality index (AQI) is a way to get information about how polluted an area is. A lot of different numbers are used to show how dangerous air pollution is at any given time. The amount of different toxins, like particulate matter, ground-level ozone, carbon monoxide, and sulfur dioxide, is measured to get the AQI.In a way, they’re like weather reports in that they tell people about the situations in their area. There are, however, different ratings for each country that are based on different air quality standards. So, what is called “moderate” air pollution in one place might be thought of as “low-risk” in another. For instance, in Canada the AQI ranges from 1 to 10, while in the UK it ranges from 0 to 500. So, in the UK, an AQI of 10 would mean “low risk,” but in Canada, it would mean “very high risk.”