What are the harmful components of smog?
Smog can also contain other harmful components such as nitrogen oxides, volatile organic compounds, sulphur dioxide and carbon monoxide. As the colour of smog is determined by the suspended particles which compose it, smog is sometimes colourless.
What is smog and why is it harmful?
Smog is a harmful mixture of fog, dust and air pollutants such as nitrogen oxides, volatile organic compounds, etc. which combine with sunlight to form a dense layer of ground-level ozone. Ozone present high in the atmosphere is good, but when nearer to the ground, it can cause irritating health effects.
What is smog and how it is harmful for US?
Smog is air pollution that reduces visibility.The term "smog" was first used in the early 1900s to describe a mix of smoke and fog.The smoke usually came from burning coal.Smog was common in industrial areas, and remains a familiar sight in cities today. Today, most of the smog we see is photochemical smog.Photochemical smog is produced when sunlight reacts with nitrogen oxides and at least ...
What is smog and how is it caused?
Smog is a kind of air pollution, originally named for the mixture of smoke and fog in the air. Classic smog results from large amounts of coal burning in an area and is caused by a mixture of smoke and sulfur dioxide. Smog is a problem in a number of cities and continues to harm human health. What is smog and its types?
What are the two main components of smog?
Smog is made up of many chemicals including nitrogen oxides (NOx), sulphur dioxide (SOx), carbon monoxide (CO), and volatile organic compounds (VOCs), but the two main components of smog are particulate matter (PM) and ground-level ozone (O3).
What are the 3 major ingredients of photochemical smog?
The formation of photochemical smog consists of three main ingredients. Moreover, these ingredients are nitrogen oxides, hydrocarbons, and sunlight.
What are the three main causes of smog?
Nitrogen oxides come from car exhaust, coal power plants, and factory emissions. VOCs are released from gasoline, paints, and many cleaning solvents. When sunlight hits these chemicals, they form airborne particles and ground-level ozone—or smog.
What is the main chemical in photochemical smog?
The major undesirable components of photochemical smog are nitrogen dioxide (NO2), ozone (O3), PAN (peroxyacetylnitrate), and chemical compounds that contain the –CHO group (aldehydes). PAN and aldehydes can cause eye irritation and plant damage if their concentrations are sufficiently high.
What are the three types of smog?
At least two distinct types of smog are recognized: sulfurous smog and photochemical smog. Sulfurous smog, which is also called “London smog,” results from a high concentration of sulfur oxides in the air and is caused by the use of sulfur-bearing fossil fuels, particularly coal.
What are the three other names for photochemical smog?
Synonymsexhaust fumes.pollution.fog.haze.vapour.pea-souper.
How is smog formed?
Smog formation in general relies on both primary and secondary pollutants. Primary pollutants are emitted directly from a source, such as emissions of sulfur dioxide from coal combustion. Secondary pollutants, such as ozone, are formed when primary pollutants undergo chemical reactions in the atmosphere.
What is the main source of smog?
Man-made smog is derived from coal combustion emissions, vehicular emissions, industrial emissions, forest and agricultural fires and photochemical reactions of these emissions .
How many people died in the Great Smog of 1952?
The Great Smog of 1952 darkened the streets of London and killed approximately 4,000 people in the short time of four days (a further 8,000 died from its effects in the following weeks and months). Initially, a flu epidemic was blamed for the loss of life.
What is smog in Los Angeles?
"Fighting Smog in Los Angeles", Distillations Podcast, 2018 Science History Institute. Smoke fog, or smog for short, is a type of intense air pollution. The word "smog" was coined in the early 20th century, and is a contraction ( portmanteau) of the words smoke and fog to refer to smoky fog due to its opacity, and odor.
What is smog in science?
Smog. For other uses, see Smog (disambiguation). Not to be confused with Smoke. Smoke fog, or smog for short, is a type of intense air pollution. The word "smog" was coined in the early 20th century, and is a contraction ( portmanteau) of the words smoke and fog to refer to smoky fog due to its opacity, and odor.
Why is Los Angeles a smog city?
Because of their locations in low basins surrounded by mountains, Los Angeles and the San Joaquin Valley are notorious for their smog. Heavy automobile traffic, combined with the additional effects of the San Francisco Bay and Los Angeles/ Long Beach port complexes, frequently contribute to further air pollution.
How does air pollution affect asthma?
There is a lack of knowledge on the long-term effects of air pollution exposure and the origin of asthma. An experiment was carried out using intense air pollution similar to that of the 1952 Great Smog of London. The results from this experiment concluded that there is a link between early-life pollution exposure that leads to the development of asthma, proposing the ongoing effect of the Great Smog. Modern studies continue to find links between mortality and the presence of smog. One study, published in Nature magazine, found that smog episodes in the city of Jinan, a large city in eastern China, during 2011–15, were associated with a 5.87% (95% CI 0.16–11.58%) increase in the rate of overall mortality. This study highlights the effect of exposure to air pollution on the rate of mortality in China. A similar study in X'ian found an association between ambient air pollution and increased mortality associated with respiratory diseases.
How does smog form?
Smog forms when pollutants are released into the air. The pollutants are formed both naturally and by humans, however, the human-induced pollutants are of most concern due to the magnitude of pollutants produced by the burning and extraction of fossil fuels, which are known to cause extreme health effects. The location of smog formation is also of great concern, especially for human health, as a good portion of it is produced within cities where large portions of the population live.
What is the effect of PM on plants?
The chemical composition of the PM may also have an effect on the plants and their surrounding soil. Particulate matter causes the presence of haze in the air, thus reducing the clarity and colour of what can be seen. Humidity of the surrounding air also plays a role in its hazy effect.
How does particulate matter affect plants?
It can also affect synthetic materials like rubber, cotton and other materials, causing deterioration and even disintegration. Particulate matter smothers plants limiting their exposure to the sun and inhibiting their ability to take in carbon dioxide, therefore, decreas ing its photosynthesis capabilities.
What is the main contributor to the formation of small PM?
It is also one of the main contributors to the formation of small PM. Carbon monoxide (CO): CO is an air pollutant that effects health and in high concentrations is very deadly.
How is ozone created?
One of the primary constituents, ozone, is created through chemical reactions between sunlight and certain pollutants. The other primary constituent, particulate matter, can also form through chemical reactions but is introduced to the atmosphere through other means as well.
What is the damage caused by PM?
These small particles can penetrate deep and cause damage. The cardio-respiratory (heart-lung) system are damaged the most from PM, resulting in infections, asthma, bronchitis, emphysema, black lung and more.
What is smog in London?
Normal smog (often called London-type smog) is mainly a product of burning large amounts of high sulfur coal. Whereas photochemical smog is a more modern phenomena commonly produced by vehicle emissions in contact with sunlight —mostly from burning gasoline and diesel. Photochemical smog forms in warm, densely populated cities with many vehicles. ...
What is the toxic gas ozone?
The highly toxic gas ozone arises from the reaction of nitrogen oxides with hydrocarbon vapours in the presence of sunlight, and some nitrogen dioxide is produced from the reaction of nitrogen oxide with sunlight.
What is smog in Los Angeles?
This type of smog is aggravated by dampness and a high concentration of suspended particulate matter in the air. Photochemical smog , which is also known as “Los Angeles smog,” occurs most prominently in urban areas that have large numbers of automobiles. It requires neither smoke nor fog.
What are the two types of smog?
At least two distinct types of smog are recognized: sulfurous smog and photochemical smog. Sulfurous smog, which is also called “London smog,” results from a high concentration of sulfur oxides in the air and is caused by the use of sulfur-bearing fossil fuels, particularly coal.
What is smog in India?
At least two distinct types of smog are recognized: sulfurous smog and photochemical smog.
Where does smog occur?
Smog over a village in Punjab state, India.
Does smog require fog?
It requires neither smoke nor fog. This type of smog has its origin in the nitrogen oxides and hydrocarbon vapours emitted by automobiles and other sources, which then undergo photochemical reactions in the lower atmosphere. The highly toxic gas ozone arises from the reaction of nitrogen oxides with hydrocarbon vapours in the presence of sunlight, ...
What is an encyclopedia editor?
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. ...
What is the name of the pollution caused by the burning of fossil fuels?
2) Photochemical Smog. Also known as Los Angeles or Summer Smog, photochemical smog is the form of pollution that is the result of large scale emissions from the burning of fossil fuels from automobiles and large industries.
What is smog in the air?
Smog is a dense and visible form of air pollution that is caused by human activity . It consists of concentrated levels of smoke, nitrogen, sulfur oxides, and other small particles. It results from the industrial and domestic burning of fossil fuels as well as emissions from automotive transport.
What is the first element that needs to be in place for smog to form?
The first element that needs to be in place for smog to form is a temperature inversion layer . It is a layer of warmer that lies on top of colder air, preventing the air underneath it from escaping. Inversion can occur naturally or as a result of the Heat Island Effect .
What are the causes of smog?
It results from the industrial and domestic burning of fossil fuels, as well as emissions from automotive transport. Apart from smoke and emissions, smog contains secondary pollutants that also play a part in the effect on humans and the environment.
How does industrial smog affect the lungs?
It is mainly due to the amount of tar and acidity in the air that directly influence and damage the lungs.
What type of pollution was created during the Industrial Revolution?
1) Industrial Smog. Also known as London or Winter Smog, industrial smog is the type of pollution that originated during the Industrial Revolution as a result of the large-scale burning of coal in industries and households. Cities like London were severely affected by the burning of coal during the nineteenth and twentieth centuries.
How many people died in the smog in 1952?
The single worst event ever was recorded in December 1952 when the official reports showed that 4 000 people perished (It is estimated that the actual number may be as high 12 000.)
Where Can You Live to Avoid Smog?
You can check different locations for air quality when considering where to live. Cities in California lead the list due to the effects of sun and high levels of vehicular traffic.
What is the name of the day when air pollution is bad?
These have different names depending on the agency. They may be called a Smog Alert, Air Quality Alert, Ozone Action Day, Air Pollution Action Day, Spare the Air Day, or many other terms.
How to protect yourself from air pollution?
How to Protect Yourself From Air Pollutants 1 0 to 50: Green. Good air quality. 2 51 to 100: Yellow. Moderate air quality. People who are unusually sensitive to ozone may experience respiratory symptoms. 3 101 to 150: Orange. Unhealthy air quality for sensitive groups including people with lung disease or heart disease, older adults, and children. 4 151 to 200: Red. Unhealthy for everyone, with special concern for sensitive groups. 5 201 to 300: Purple. Health alert level indicating very unhealthy conditions, everyone may experience serious health effects. 6 301 to 500: Maroon. Hazardous, an emergency condition for the entire population.
What is the name of the chemical that causes smog?
One of the primary components of photochemical smog is ozone.
What to do when you see smog advisory?
When you see this advisory, those sensitive to smog should reduce their exposure, including refraining from prolonged or heavy exertion outdoors. Become familiar with what these days are called in your area and pay attention to them in weather forecasts and on weather apps. You can also check the Action Days page at the AirNow.gov website.
How is ozone formed?
Ground-level ozone is formed when vehicle emissions containing nitrogen oxides (primarily from vehicle exhaust) and volatile organic compounds (from paints, solvents, and fuel evaporation) interact in the presence of sunlight. Therefore, some of the sunniest cities are also some of the most polluted.
What are the problems with a symtom?
Problems include shortness of breath, coughing, wheezing, bronchitis, pneumonia, inflammation of pulmonary tissues, heart attacks, lung cancer, increased asthma-related symptoms, fatigue, heart palpitations, and even premature aging of the lungs and death.
Overview
Photochemical smog
Photochemical smog, often referred to as "summer smog", is the chemical reaction of sunlight, nitrogen oxides and volatile organic compounds in the atmosphere, which leaves airborne particles and ground-level ozone. Photochemical smog depends on primary pollutants as well as the formation of secondary pollutants. These primary pollutants include nitrogen oxides, particul…
Etymology
Coinage of the term "smog" is often attributed to Dr. Henry Antoine Des Voeux in his 1905 paper, "Fog and Smoke" for a meeting of the Public Health Congress. The 26 July 1905 edition of the London newspaper Daily Graphic quoted Des Voeux, "He said it required no science to see that there was something produced in great cities which was not found in the country, and that was smoky fog, or what was known as 'smog'." The following day the newspaper stated that "Dr. De…
Anthropogenic causes
Coal fire can emit significant clouds of smoke that contribute to the formation of winter smog. Coal fires can be used to heat individual buildings or to provide energy in a power-producing plant. Air pollution from this source has been reported in England since the Middle Ages. London, in particular, was notorious up through the mid-20th century for its coal-caused smogs, which were nicknamed "pea-soupers". Air pollution of this type is still a problem in areas that generate signifi…
Health effects
Smog is a serious problem in many cities and continues to harm human health. Ground-level ozone, sulfur dioxide, nitrogen dioxide and carbon monoxide are especially harmful for senior citizens, children, and people with heart and lung conditions such as emphysema, bronchitis, and asthma. It can inflame breathing passages, decrease the lungs' working capacity, cause shortness of breath, p…
Areas affected
Smog can form in almost any climate where industries or cities release large amounts of air pollution, such as smoke or gases. However, it is worse during periods of warmer, sunnier weather when the upper air is warm enough to inhibit vertical circulation. It is especially prevalent in geologic basins encircled by hills or mountains. It often stays for an extended period of time over densely popula…
Pollution index
The severity of smog is often measured using automated optical instruments such as nephelometers, as haze is associated with visibility and traffic control in ports. Haze, however, can also be an indication of poor air quality, though this is often better reflected using accurate purpose-built air indexes such as the American Air Quality Index, the Malaysian API (Air Pollution Index), and the Si…
Cultural references
• The London "pea-soupers" earned the capital the nickname of "The Smoke". Similarly, Edinburgh was known as "Auld Reekie". The smogs feature in many London novels as a motif indicating hidden danger or a mystery, perhaps most overtly in Margery Allingham's The Tiger in the Smoke (1952), but also in Dickens's Bleak House (1852) and T.S. Eliot's "The Love Song of J. Alfred Pruf…
Formation
Health Effects of Smog
- The health effects from smog and its components can be severe, and depend on many variables. Smog is harmful when inhaled, with the severity of it depending on the amount inhaled, the types of pollutants contained in it, as well as the individual's age, weight, activity level, and well-being. However studies show that anyexposure to these pollutants is harmful, with extended exposure …
Environmental Impacts
- Smog affects much more than just human lives; it also has a large impact on the surrounding physical environment. Ozone and PM in particular cause damaging effects: Ozone can damage plant cells and inhibit their growth, reducing the amount of carbon dioxide that they take in during photosynthesis. This results in reduced agricultural yields in all sorts of crops. It can also affect s…
For Further Reading