Table of Contents
- What is Air Pollution?
- Types of air pollution
- What Causes air pollution?
- Human-made (anthropogenic) sources of air pollution
- Natural sources of air pollution
- What are the effects of air pollution?
- Solutions for air pollution
- Air pollution facts
What is Air Pollution?
The Clean Air Act in the U.S which was established in 1970 authorizes the U.S Environmental protection Agency (EPA) to regulate the emissions of these hazardous air pollutants in order to safeguard public health. According to WHO, almost all the population worldwide breathes air that exceeds the WHO guidelines limits containing high levels of pollutants. Each year, nearly seven million deaths around the world are caused by air pollution. The data shows that low-income and middle-income countries suffer the highest exposure and as a result WHO is supporting countries to address air pollution.
Nevertheless, there are six major air pollutants that their concentrations in the atmosphere are useful as indicators of overall air quality. In regard to this, The US Environmental protection Agency (EPA) has designated these pollutants as “criteria” pollutants. These criteria air pollutants are found all over the U.S and as earlier said the EPA is required by the Clean Air Act to set National Ambient Air Quality Standards (NAAQS) for them.
However, regardless of the progress made in the last 30 years, there are still millions of people that live in counties with monitored concentration data that shows unhealthy air for one or more of the six EPA criteria air pollutants. These six EPA criteria air pollutants include:
- Ground-level ozone
- Particulate matter
- Carbon monoxide
- Sulfur dioxide
- Nitrogen dioxide
This air pollutant is formed by a complex reaction of nitrogen dioxide and hydrocarbons in the presence of sunlight. Ozone is a major component of photochemical smog and is said to be a criteria pollutant in the lowermost layer of the atmosphere (troposphere). However, in the upper atmosphere, ozone occurs naturally to block harmful ultraviolet rays from the sun.
It is an essential component of the ozone layer in the stratosphere and is involved in the photochemical and chemical reactions that drive many of the processes that take place in the atmosphere day and night. However, ozone at abnormally high concentrations becomes a pollutant and constituent of smog due to human activities that involve the combustion of fossil fuels.
In cities where sunshine is ample and highway traffic is heavy e.g Los Angeles, photochemical smog tends to be common. This is because nitrogen dioxide and hydrocarbons that form ozone are emitted in significant quantities by motor vehicles.
This particulate matter is an example of air pollutants and can be called fine particulate, particulate matter (PM), atmospheric particulate matter, or fine particles. They are very small fragments of liquid droplets or solid material suspended in gas or air.
Particulates are characterized based on their size or phase (solid or liquid) instead of chemical composition. For instance, airborne solids with a diameter less than 1μm are referred to as fumes while solid particulates with diameters between 1-100 μm are referred to as dust particles. Anthropogenic sources of particulate emissions include fossil-fuel power plants, manufacturing processes, gasoline-powered vehicles, and fossil-fuel residential heating systems. However, there are some natural sources of particulates which are volcanoes, dust storms, sea spray, forest fires, living vegetation, and grassland fires.
Particulates solids with a diameter less than 10 μm are the particulates of most concern because they can be inhaled deep into the lungs. They get trapped in the lower respiratory system of humans once they are inhaled deep. Hence, an increase in the level of fine particles in the air is associated with health hazards like altered lung function, heart disease, and lung cancer.
This gas is colorless and toxic. It is generated from incomplete combustion of fuel (natural gas, wood, or coal) and is the most abundant of the criteria pollutants. The sources of carbon monoxide (CO) include industrial processes, residential heating systems, and gasoline-powered highway vehicles (primary source).
Carbon monoxide can replace oxygen in the bloodstream and this is why exposure to it can be acutely harmful. High exposure time and concentration can lead to asphyxiation (the process of being deprived of oxygen, which can result in unconsciousness, suffocation, or death). CO forms a kind of smog in the atmosphere that has been linked to several lung diseases.
Toxic metals like mercury, lead and their compounds are examples of air pollutants. Oil refining, smelting, and other industrial activities are the main sources of airborne lead particulate. In the past, gasoline contained tetraethyl, a lead-based antiknock additive. Hence, when this gasoline is combusted, it releases lead particulates and was a major source.
There is, however, a complete ban on the use of lead in gasoline in many countries. Hence, there was a more than 90% decrease in the lead concentration in outdoor air in the United States. This was after the use of leaded gasoline was restricted in the mid-1970s and completely banned later on in 1996. Lead particulates, when inhaled in form of dust and fumes, can be harmful especially to children. In children, slightly elevated levels of lead in the blood can cause seizures, learning disabilities, and even death.
This gas is colorless and has a choking odor. Petroleum and coal usually contain sulfur compounds and that is why the gas is formed when coal or oil that has sulfur as an impurity is combusted.
Most of the sulfur dioxide (SO2) emitted is generated from power generating plants, volcanoes and very little comes from mobile sources. Sulfur dioxide can cause throat and eye irritation and when inhaled can harm the lung tissue.
This gas is also a component of acid rain. In the air, it reacts with oxygen and water vapor to form a mist of sulfuric acid that falls to the ground as acid rain (acid deposition).
This gas (NO2) is a pungent irritating gas that reacts in the atmosphere to form nitric acid which contributes to acid rain. Nitrogen dioxide is the most concern of all the several forms of nitrogen oxides. High-temperature combustion produces oxides of nitrogen and causes molecular nitrogen in the air to react with oxygen.
Coal-burning power plants are therefore the primary source of NO2, followed by gasoline engines and other mobile sources. In addition, nitrogen oxides are also produced by electric discharge during thunderstorms. This gas causes pulmonary edema (a condition due to excess fluid in the lungs) and contributes to the formation of photochemical smog.
Types of air pollution
- Smog pollution
- Soot pollution
- Hazardous air pollution
- Pollution from greenhouse gases
- Pollen and mold pollution
This type of air pollution reduces visibility and the term “smog” was used in the 1900s to describe the combination of smoke and fog. Pollution as a result of smog occurs when the emissions from fossil fuels combustion react with sunlight. Smog is sometimes referred to as ground-level ozone. The sources of smog are anthropogenic and come from the combustion of fossil fuels like natural gas, coal, or gas.
It is very common in industrial areas and is seen in cities today. It is familiar in big cities with traffic and a lot of industries. Also, cities that are surrounded by mountains and located in basins may have smog problems. This is because the smog cannot be carried away by the wind and is trapped in the valley. Partly because of this kind of landscape, cities like Los Angeles, California, and Mexico City, Mexico have high smog levels.
Smog is harmful especially to children, elderly people, and people that exercise or work outdoor. It can damage the lungs as well as cause throat and eye irritation. The effect is worst on people with allergies or asthma. Hence, it can trigger asthma attacks and intensify symptoms of allergy. Smog is not only unhealthy to animals and humans, plants can be killed too. Aside from the adverse effect caused by smog, it reduces the aesthetic value of the environment as it makes the sky ugly by looking brown or gray.
In response to the high levels of smog, several countries including the U.S have created laws to help reduce smog. Some of these laws involve restrictions on the type of chemicals, industries can emit into the atmosphere as well as when they can release them. Some communities even have days (burn days) set aside for residents to burn their yard waste. These restrictions and limits help to reduce the amount of smog in the atmosphere. However, there are two types of smog which include photochemical and sulfurous smog.
Types of smog
- Photochemical smog
- Sulfurous smog
Currently, the majority of the smog seen is photochemical smog. This type of smog is also known as Los Angeles smog and is produced when sunlight reacts in the atmosphere with at least one volatile organic compound (VOC) and nitrogen oxides. Ground-level ozone and airborne particles are formed when sunlight reacts with these chemical compounds resulting in smog. The major sources of nitrogen oxides are coal power plants, car exhaust, and factory emissions. Whereas, the sources of VOCs include paints, gasoline, and several cleaning solvents.
Photochemical smog is common in urban areas with massive numbers of automobiles. Once automobiles release hydrocarbon vapors and nitrogen oxides, these chemical compounds get acted upon by sunlight (photochemical reaction) in the lower atmosphere. As a result of the reaction of NOx and hydrocarbon vapors, ozone a highly toxic gas is produced. Also, some nitrogen oxides are produced from the reaction of nitrogen oxide and sunlight.
The resulting photochemical smog gives the atmosphere a light brownish coloration and reduces visibility. It causes damage to plants and eye irritation and respiratory distress in humans. Surface-level ozone concentrations are unhealthy once they exceed 70 parts per billion for 8 hours or more. This is fairly common in urban areas that are susceptible to photochemical smog.
This type of smog is also referred to as London smog. London for years has been synonymous with sulfurous smog. This is why the name London smog was coined at the turn of the 20th century to describe the city’s characteristic smog.
Sulfurous smog is formed due to a high level of sulfur oxides concentration in the atmosphere. The major source of sulfur oxides in the air is the burning of sulfur-bearing fossil fuels, especially coal. A high concentration of suspended particulate matter and the amount of dampness in the air aggravate sulfurous smog.
This type of air pollution is also referred to as particulate matter pollution because it consists of tiny particles of soil, chemicals, smoke, allergens, or dust. These particles are carried in the air in form of either solid or gas which can penetrate the lungs and bloodstream. Hence, the tiniest airborne particle in soot can worsen bronchitis, cause heart attack, and can even be fatal. This air pollutant comes from various sources and is a result of some kind of pyrolysis. Soot sources are anthropogenic and come from the combustion of fossil fuels like natural gas, coal, or gas. Other sources of soot include:
- Internal-combustion engines
- Boilers (power-plant boilers, hog-fuel boilers, ship boilers, and central steam-heat boilers)
- Waste incineration
- Local field burning and smoking of plant matter
- House fires and fireplaces
- Forest fires
- Use of oil lamps or candles
- Quartz/halogen bulbs with settled dust
- Exhaust emissions from vehicles
- Defective furnaces
The soot pollution as a result of diesel exhaust is responsible for more than one-quarter of the total hazardous air pollution. In low concentrations, soot can darken surfaces or make particles agglomerates appear black. The discoloration of walls, ceilings, and floors is caused by soot. However, soot formation is based mainly on the fuel composition. Based on fuel components, in the rank ordering of sooting tendency, Napthalenes rank more than benzenes and aliphatics while benzenes rank more than aliphatics. However, in aliphatics (alkanes, alkynes, and alkenes), the flame type determines the order of sooting tendencies.
Soot from diesel exhaust (DE) has been linked with acute vascular dysfunction and increased thrombus formation. Particulate matter with a diameter of less than 10μm especially fine particles (PM2.5) and ultra-fine particles (PM0.1) is associated with diseases such as chronic lung disease, influenza, asthma, lung cancer, and increased rate of mortality. In fact, long-term exposure to urban soot pollution can increase the risk of coronary artery disease.
According to a study (Harvard’s T. H. Chan School of Public Health) in 2020, it was shown that areas with more soot pollution had high COVID-19 mortality rate than areas with less soot pollution. This means there is a correlation between the deadliness of the covid-19 virus and long-term exposure to particulate matter.
It was discovered in 2019 by the Union of Concerned Scientists that soot exposure was 34% higher for Asian Americans on an average than for other Americans. The exposure rate for black people was 24% higher and 23% higher for Latinos. This report is obviously because highways and polluting facilities have been historically sited in or close to low-income neighborhoods or black communities. Hence, people in such communities tend to experience the negative effects of this pollution.
Pollution from Hazardous air pollutants
There are some hazardous substances that pose severe health risks and ecological problems when released into the atmosphere. Sometimes, even in small amounts, these hazardous air pollutants can be fatal. Common hazardous air pollutants types include lead, mercury, benzene, dioxins, etc, and about 200 of these types of air pollutants are regulated by law. These pollutants are usually released during incinerating, coal/gas combustion, or are found in gasoline such as benzene.
Benzene is a carcinogen and causes skin, eye, and lung irritation in short term as well as blood disorders in long term. Dioxins are present in small amounts in the air and short-term exposure can affect the liver whereas, long-term exposure can harm the nervous, immune, reproductive, and endocrine systems.
Heavy metals like mercury and lead in the atmosphere can cause air pollution. Mercury can attack the central nervous system when inhaled. Lead, on the other hand, in large amounts tends to damage the kidneys and brains of children. A child’s IQ and ability to learn can be affected even by minimal exposure to lead.
Polycyclic aromatic hydrocarbons (PAHs) are another group of hazardous air pollutants. They are by-products of wildfire smoke and traffic exhaust. They are cancerous and tend to cause lung irritation, liver issues, eye irritation, and blood issues when in large amounts. A study conducted showed that the children of the pregnant mothers that were exposed to PAHs exhibited slower brain-processing speeds and more conspicuous symptoms of ADHD (attention deficit hyperactivity disorder).
Pollution from greenhouse gases
Air pollution results from the presence of greenhouse gases in the atmosphere. Greenhouse gases are a type of gaseous air pollutants that trap the earth’s heat in the atmosphere which leads to warmer temperatures. As the planet warms up, climate change (see causes of climate change) takes place which results in rising sea levels, heat-related deaths, more extreme weather, and an increase in the transmission of infectious disease.
Greenhouse gases include fluorinated gases which are synthetic and other gases like carbon dioxide, methane, nitrous oxide, and water vapor that occur naturally. Methane is released from natural and industrial sources and carbon dioxide is released during the combustion of fossil fuels. A larger amount of carbon dioxide is emitted compared to methane but methane is significantly more potent and destructive.
The hydrofluorocarbons (HFCs) are said to be far more powerful than carbon dioxide in their ability to trap heat. As a result, more than 140 countries in October 2016 reached an agreement to reduce the use of HFCs which are found in refrigerators and air conditioners.
Pollen and mold pollution
The mold and allergens from trees, grass, and weeds that are carried in the air can cause a type of air pollution. They are usually hazardous to health when aggravated by climate change. Pollen and mold in the air can be considered a type of air pollution even though they are not regulated and are less directly connected to anthropogenic activities.
In a school, business, or home, mold can grow when there is water damage and can produce allergenic airborne pollutants. Some molds can even produce toxins that are hazardous for humans to inhale. Moreso, mold exposure can bring about an allergic response or asthma attacks.
Due to climate change, pollen allergies are worsening. It is seen in lab and field studies that pollen-producing plants like ragweed tend to grow larger and produce more pollen when there is an increase in the carbon dioxide that they grow in. Also, climate change extends the pollen production season. Some studies are even beginning to suggest that ragweed pollen might become a more potent allergen. This means that if this is true, more people will suffer fevers, runny noses, itchy eyes, and other symptoms.
What Causes air pollution?
- The burning of fossil fuels is one of the major causes of air pollution as it emits air pollutants like sulfur dioxide into the environment.
- Incomplete combustion of petroleum in vehicles like cars, trucks, trains, planes, etc releases air pollutants like particulate matter, nitrogen oxides, lead, carbon monoxide, and organic compounds.
- Agricultural activities that involve the use of pesticides, insecticides, and fertilizers including burning are one of the causes of air pollution. Ammonia is one of the frequent gases released into the atmosphere from agricultural-related activities.
- The waste in landfills contributes to air pollution as methane, a greenhouse gas is generated from this buried waste.
- Factories and industries exhaust release a large number of organic compounds, chemicals, hydrocarbons, and carbon monoxide into the atmosphere.
- Mining activities are another cause of air pollution because, during the process of mining, dust and chemicals are released into the air.
- The usage of some man-made products such as painting supplies, household cleaning products, etc emits toxic chemicals into the air.
- Natural events such as forest fires, dust storms, volcanoes, radioactive decay, and vegetation are also causes of air pollution
- Human-made (anthropogenic) sources
- Natural sources
The sources of air pollution are the various location, activities, or factors that are responsible for the presence of pollutants in the atmosphere. These various activities or emissions are the major cause of air pollution and come from several sources, grouped into two:- anthropogenic and natural sources.
Anthropogenic sources are based on human activities and are mostly related to the burning of different sorts of fuels. Whereas, the natural source is based on natural occurrences. These natural sources can be significant sometimes but do not normally create as many air pollution problems as anthropogenic sources.
Human-made (anthropogenic) sources of air pollution
- Stationary sources
- Military source
- Agricultural emissions
- Forestry management
- Man-made products
- Mining operations
- Mobile sources
These are areas where waste is deposited or buried. The waste deposited in landfills generates methane into the atmosphere. Even though methane is not toxic, it is highly flammable and can form explosive mixtures with air. In an enclosed space, methane as an asphyxiate can displace oxygen. Once, the oxygen concentration is lower than 19.5% by displacement, suffocation or asphyxia can take place.
Also, a lot of unscientific dismantling such as burning wires, chemical leaching, etc is involved in E-waste (Electronic waste which is discarded electrical or electronic devices). Moreso, a major source of air pollution in developing and poor countries is the burning of traditional biomass which includes wood, dung, and crop waste.
This involves the smokestacks of manufacturing industries, waste incinerators, furnaces, and power plants. Other types of fuel-burning heating devices are sources of air pollution as well. These stationary sources emit large amounts of pollution from a single location which is referred to as point sources of pollution.
The burning of fossil fuels such as petroleum, and coal for energy emits air pollutants like sulfur dioxide into the environment. A large number of organic compounds, chemicals, hydrocarbons, and carbon monoxide are released from the exhaust of factories and industries into the atmosphere. Hence, depleting the air quality.
A 2014 study of air pollution in china showed that China’s construction sector and manufacturing sectors for machinery, devices, and equipment were responsible for more than 50% of the emission of air pollutants.
Weapons used by the military such as toxic gases, nuclear weapons, rocketry, and germ warfare are also a cause of air pollution because they emit pollutants into the atmosphere when in use.
Emissions occur during the use of pesticides, insecticides, and fertilizers in agricultural activities. The harmful chemicals released into the air can also cause water pollution. Ammonia happens to be one of the frequent gases released into the atmosphere from agricultural-related activities. This gas is very hazardous in the atmosphere.
Also, as farmers set their old crops and fields on fire, harmful gases are released into the atmosphere. This burning practice is usually done by farmers to keep the field clean for the next round of sowing. Farmlands that are fertilized may be a source of nitrogen oxides which is one of the criteria air pollutants. Hence, agricultural emissions contribute immensely to the pollution of the environment.
This is also a source of air pollution as chemicals, dust, and controlled burn practices are implemented in this field. Foresters use controlled fire as a tool since fire is a natural part of the forest and grassland ecology. In forest management, the controlled or prescribed burning technique is used. This technique is also used in farming, greenhouse gas abatement, or prairie restoration. The controlled burning renews the forest as it usually stimulates the germination of some desirable forest trees.
There are fumes that emit from manmade products that pollute the air. These fumes can be air pollutants and their sources are products like paints, aerosol sprays, hair spray, varnish, household cleaning products, and other solvents. The toxic chemicals emitted in the air by some of these man-made products cause air pollution.
According to WHO, the combined effects of household and outdoor air pollution cause about 7 000 000 premature deaths every year. Moreso, in the 2010s, emissions from such man-made product sources were responsible for almost half of pollution from volatile organic compounds in the Los Angeles basin.
During the process of mining, minerals that are below the earth are extracted using large equipment which releases chemicals and dust into the air. Thereby causing air pollution which is one of the reasons why there is deterioration in the health conditions of most of the workers as well as the neighboring residents.
This source accounts for more than half of all the air pollution. According to the Environmental Protection Agency, the automobile is the primary mobile source of air pollution. Other mobile sources include buses, trucks, aircraft, trains, marine vessels, etc. Humans rely on these sources because they are our daily means of transportation modes.
However, the overuse of these mobile sources is harming and polluting the atmosphere. There are billions of vehicles running on the road that burn petroleum for energy release. Unfortunately, the incomplete combustion of petroleum in vehicles releases air pollutants like particulate matter, nitrogen oxides, lead, carbon monoxide, and organic compounds.
Natural sources of air pollution
- Radioactive decay
- Food digestion in ruminant animal
- Forest fire/wildfires
The radioactive decay that takes place within the crust of the earth emits a colorless, odorless, and naturally occurring gas known as radon gas. This radioactive noble gas is formed from the decay of radium and is said to be a health hazard. The radon gas from this natural source can accumulate in building, most especially in confined spaces. It is said that after cigarette smoking, this gas is considered to be the second most frequent cause of lung cancer.
Dust from large land areas with little or no vegetation can naturally pollute the atmosphere. Dust, as well as combustion, causes Suspended particulate matter (SPM) to float in the air which is a form of air pollution.
Food digestion in ruminant animals
Food digestion is a natural phenomenon but can also be one of the natural sources of air pollution. As food is digested by animals such as cattle, methane is emitted into the atmosphere. Cattle, sheep, deer, buffalo, elk, camels, giraffes, goats, etc as ruminant animals, have a specialized digestive system that enables them to digest and break down food that cannot be easily digested by nonruminants like humans.
These animals have four stomach compartments where one of the compartments (rumen) allows them to store partially digested food and let the food ferment. They later regurgitate the food and complete the digestive process. The greenhouse gas, methane as well as other by-product is produced as the food (grass and other vegetation) ferments in the rumen. The cattle eventually expel the methane gas as they belch. Hence, as ruminant animals digest their food, they naturally contribute to the amount of methane gas in the atmosphere.
During a volcanic activity, sulfur, ash particulates, and chlorine are produced and released into the atmosphere.
Wildfire contributes as a source of air pollution as smoke and carbon monoxide are emitted into the environment during the process of burning. It is said that the smoke from the uncontrolled combustion of biomass can make up almost 75% of all air pollution by concentration.
In some regions, vegetation on warmer days releases environmentally significant amounts of volatile organic compounds (VOCs). Examples of such vegetation that release VOCs in abundance include willow, poplar, oak, and black gum.
The volatile organic compounds emitted by the vegetation react with primary air pollutants (Sulfur dioxide and nitrogen oxides) and human-made organic carbon compounds. This reaction leads to the production of the seasonal haze of secondary pollutants. This production of VOCs from vegetation leads to ozone levels that are up to eight times higher than the low-impact tree species.
What are the effects of air pollution?
- It causes respiratory and heart diseases
- Air pollution cause cancer and other diseases
- Children’s health is threatened
- Air pollution causes global warming
- It results in climate change
- Eutrophication in water bodies
- Affects wildlife and plants
- Air pollution results in acid rain
- Polluted air damages the ozone layer
- Facilitate the Spread of Epidemics
Respiratory and heart diseases
One of the effects of air pollution is that it causes heart and respiratory diseases in humans. Health conditions such as chronic bronchitis, asthma, emphysema, strokes, and heart attacks can be associated with air pollution. About 3.8 million premature deaths are recorded each year as a result of exposure to smoke from cooking fires in mostly low and middle-income countries. Burning fuels releases a lot of health-damaging pollutants such as methane, particulate matter, methane, carbon monoxide, polyaromatic hydrocarbons, and volatile organic compounds.
Cancer and other diseases
There are so many studies that prove that there is a direct relationship between adverse health impacts and exposure to particulate matter. Smaller-diameter particles such as PM2.5 or lesser can penetrate tissues and organs causing diseases like lung cancer. Many air pollutants are carcinogenic and cause leukemia. Some cause lung irritation, eye irritation, blood issues, and liver issues.
For instance, benzene is a carcinogen and causes skin, eye, and lung irritation in short term as well as blood disorders in long term. Also, short-term exposure to dioxins can affect the liver while, long-term exposure can harm the nervous, immune, reproductive, and endocrine systems. Heavy metals like mercury can even attack the central nervous system when inhaled.
Threatens children’s health
The effect of air pollution is conspicuous on the health of our children. Air pollution causes child health problems, either through the pregnant mother or directly to the child. During pregnancy, exposure to high air pollution levels can lead to miscarriages, autism, premature birth, spectrum disorder, and asthma in young children.
Air pollutants tend to damage early brain development in children. A study showed that pregnant mothers being exposed to PAH (Poly-nuclear Aromatic Hydrocarbons) can lead to slower brain-processing speeds and ADHD (attention deficit hyperactivity disorder) in their children. Also, children that are exposed to air pollutants are at a greater risk of short-term respiratory infections, pneumonia, and pulmonary diseases. Large amounts of heavy metals like lead tend to damage the kidneys and brains of children. A child’s IQ and ability to learn can be affected even by minimal exposure to lead.
One effect of air pollution on the ecosystem is global warming. Greenhouse gases such as carbon dioxide which are air pollutants are responsible for trapping the earth’s heat in the atmosphere and causing global warming. Global warming in turn results in an increase in temperature and sea levels. Ice from cooler regions, glaciers, and icebergs tend to melt faster due to the warming of the earth.
One of the major air pollution effects on the environment is climate change. Due to the pollution of air, there is a change in the climatic conditions of the earth. When air pollutants like tropospheric ozone, aerosols, black carbon, and methane find their way to the atmosphere, they affect the amount of incoming sunlight. Aerosols, for instance, affect the climate, and as tiny as they are, they dissipate sunlight by dispersing a quarter of the sun’s rays back to space.
Over the last 30 years, aerosols have cooled the temperature of the earth. The climate change caused by air pollution also leads to a change in the season of pollination which adversely affects the ecological balance of the earth. See parameters of climate change on a global scale and effects of climate change on food security.
Eutrophication in water bodies
The polluted air that eventually settles onto water bodies can cause eutrophication. Eutrophication is a condition that occurs when there is nutrient pollution of the water which results in an algae bloom. It usually occurs due to a high amount of nitrogen. This means that emitting toxic air pollutants that contain nitrogen can settle on the sea surface and stimulate the growth of algae that cause oxygen depletion in the water. This, in turn, affects fishes, aquatic plants, and animals.
Therefore, eutrophication, as well as water pollution, can be another effect of air pollution on the environment. Once, our sources of water are contaminated, there is a lot of disadvantaged repercussion to this because humans and other organisms need water for survival.
Affects Wildlife and plants
Wildlife and plants also experience some devastating effects that air pollution causes. Take dolphins for example that suffer from black lung disease as a result of smog pollution. Apart from the health effect it causes on animals, wildlife species are instinctively forced to migrate to a new habitat due to the toxic chemical present in the atmosphere. Also, the toxic pollutants that settle on the surface of the water and can harm aquatic animals or other animals that feed on the water.
Plants are not excluded from the harmful air pollution effects. An air pollutant can enter through the plant’s stomata which it uses for transpiration and destroy the chlorophyll of the plant. As these pollutants destroy the chlorophyll, photosynthesis is affected.
Also, the cuticle (waxy coating of the leaves) of the plant is usually affected by air pollutants. The function of the cuticle is to prevent excessive water loss and damage from pests, diseases, frost, and drought. As a result of air pollution which damages the leaf structure, conditions such as abscission, necrosis, epinasty, or chlorosis take place in the plant.
One of the air pollution effects on the environment is acid rain. As fossil fuel is burned, gases like nitrogen oxides and sulfur oxides get released into the atmosphere. During precipitation, these air pollutants can get dissolved in water drops and acidify the water which later falls as acid rain. Acid rain can cause severe damage to plants, animals, and even humans.
Damages the ozone layer
One prominent effect of air pollution is that it damages the ozone layer. Ozone is a major component of photochemical smog and is said to be a criteria pollutant in the lowermost layer of the atmosphere (troposphere). However, in the upper atmosphere, ozone occurs naturally to block harmful ultraviolet rays from the sun.
The ozone layer in the earth’s stratosphere is what protects us from the harmful ultraviolet (UV) rays of the sun. In the stratosphere, ozone is usually involved in the photochemical and chemical reactions that drive many of the processes that take place in the atmosphere. However, due to the presence of air pollutants like chlorofluorocarbons, hydrochlorofluorocarbons in the atmosphere, ozone at abnormally high concentrations becomes a pollutant and constituent of smog.
Therefore, due to air pollution that involves the combustion of fossil fuels, the ozone layer is depleting. The depletion of the ozone layer will allow the harmful rays to be emitted on earth which can cause skin and eye problems. Also, UV rays will affect crops as well.
Spread of Epidemics
The spread of epidemics occurs more frequently nowadays due to climate change resulting from air pollution. Changes in climatic conditions affect the incidence and prevalence of imported infections in a country. The climatic and weather condition of a place strongly affects the timing, duration, and intensity of outbreaks. For example, viral diseases and mosquito-transmitted parasitic diseases are highly climate-sensitive (See effects of climate change and malaria). Warming due to climate change can shorten the pathogen incubation period as well shift the geographic map of the vector. Water warming due to climate change causes a high incidence of waterborne infections.
Furthermore, due to climate change following air pollution, pollen allergies are worsening. It is seen in lab and field studies that pollen-producing plants like ragweed tend to grow larger and produce more pollen when there is an increase in the carbon dioxide that they grow in. Also, climate change extends the pollen production season. Some studies are even beginning to suggest that ragweed pollen might become a more potent allergen. This means that if this is true, more people will suffer fevers, runny noses, itchy eyes, and other symptoms.
According to a study (Harvard’s T. H. Chan School of Public Health) in 2020, it was shown that areas with more soot pollution had high COVID-19 mortality rate than areas with less soot pollution. This means there is a correlation between the deadliness of the covid-19 virus and long-term exposure to the air pollutants, particulate matter.
Solutions for air pollution
- Since vehicles are one of the major sources of pollution, people should make good choices about transportation by using public transportation, carpool, taking a walk, and riding a bike.
- Electric cars or Cars that cover better miles per gallon of gas should be used more.
- One major solution for air pollution is afforestation. More trees should be planted and deforestation should be reduced.
- Fuel substitution is one of the solutions to air pollution. For instance, petrol and diesel have been replaced by CNG (Compressed Natural Gas) in many parts of India.
- Another solution to air pollution is the usage of clean energy sources like wind, geothermal and solar. This should be encouraged and implemented e.g in some countries, governments are providing grants to consumers that are interested in installing solar panels for their homes.
- Household use of fireplaces and wood stoves for heating their homes should be discouraged. Gas logs should be used instead of wood.
- Factories and industries should make use of pollution control devices that help filter the emissions before it is released into the environment.
- Certain raw materials that react to produce air pollutants can be substituted with less polluting materials in factories and industries.
- Industries should use low sulfur coal as well as maintain their existing pieces of equipment in order to minimize the emissions.
- People should use less of or totally avoid products with chemicals such as paints or perfumes.
- Usage of products with low chemicals and organic properties should be implemented more.
- It is advisable to make use of environmentally safe paints or cleaning products if possible.
- Households should purchase filters for their chimney.
- Avoid setting bonfires in the open as well as burning yard waste.
- Conserve energy to reduce the amount of fossil fuel burned to generate electricity. Switch off your light and electrical appliances when not in use.
- The usage of energy-efficient devices like CFL lights will consume less electricity and help curb air pollution.
- The concept of reducing, reuse, and recycling is one of the air pollution solutions currently implemented in some places. This will help reduce the production of new products that results in the emission of gases due to the burning of fuel for energy.
Good air quality is important for the earth’s climate and ecosystem. Hence, measures that will profer solution to air pollution should be put in place and implemented. Policies that will reduce the pollution of air will offer a win-win strategy for both our health and climate.
Solutions for air pollution can be implemented both at the household level and at industrial levels. Hence, there are several attempts being made everywhere around the globe both on personal, industrial, and governmental levels to curtail the intensity at which air pollution is rising and return our environment to its natural state.
Air pollution facts
- Every year, 4.2 million deaths occur due to outdoor air pollution exposure, according to WHO.
- About 3.8 million deaths result every year from household exposure to smoke from dirty cookstoves and fuels.
- Globally, 9 out of 10 people live in places where air quality exceeds WHO guideline limits.
- Diesel exhaust and particulate matter (PM) causes outdoor pollution and cancer. They are in the same class as tobacco.
- Plants can help filter pollution.
- Following high blood pressure, dietary risks, and smoking, air pollution is the fourth-largest threat to human health.
- According to WHO, almost all the deaths (94%) linked to air pollution happens in low- and middle-income countries. The biggest regional danger spots are parts of Africa, Eastern Europe, India, China, and the Middle East.
- The pollutants emitted into the air are far more harmful compared to the pollutants that contaminate land and water.
- Air pollution isn’t just a recent occurrence. History has it that the great smog of London killed 8000 people in 1952.
- 80% of lung disease is a result of air pollution caused by emissions from buses, cars, trucks, and other vehicles.
- According to the report given by the Environment Protection Agency (EPA) in 2014, Methane accounts for about 11% of the greenhouse gas emission while Carbon dioxide accounts for a total of 81% of the greenhouse gas emissions.
Jamar holds an M.D. from Yale University as well as a B.S. in Biology from Brandeis University. He currently conducts research in the field of Microbiology with a specialized focus on bacteria. Outside of work Jamar enjoys spending time with his family and writing about his field of study to help students and other industry professionals better understand its effects on the world.