Air pollution is the introduction of pollutants, organic compounds, or other hazardous substances into the Earth’s atmosphere. This can take the form of surplus gases such as carbon dioxide and other vapors that are not sufficiently removed by natural cycles such as the carbon or nitrogen cycles.
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Air pollution is the contamination of air caused by the presence of substances that are detrimental to human and animal health, as well as the environment and materials.
Examples of air pollution include gases (such as ammonia, carbon monoxide, sulfur dioxide, nitrous oxides, methane, carbon dioxide, and chlorofluorocarbons), particles (organic and inorganic), and living molecules.
Air pollution is associated with numerous pollution-related illnesses, including respiratory infections, heart disease, COPD, stroke, and lung cancer.
Air Pollution Chemistry Questions with Solutions
Q1: What are the natural causes of air pollution?
Answer:
Natural sources of air pollution include forest fires and volcanoes, which pollute the air with smoke and dust.
Q2: How do automobiles pollute the air?
Answer:
Automobiles typically include internal combustion engines that run on gasoline or diesel. Several hazardous gases, including carbon dioxide, carbon monoxide, sulfur dioxide, and nitrogen dioxide, are emitted when gasoline or diesel is burned. In addition, automobile engines release minute particles. As a result, automobiles contribute to air pollution.
Q3: Write a short note on the ozone layer.
Answer:
In the atmosphere, the ozone layer serves as a protective layer. It has the greatest ozone concentration of any atmospheric layer. However, compared to other gases, ozone comprises a minor portion of the ozone layer’s air. This layer prevents damaging UV rays from the sun from entering our atmosphere. UV rays cause skin cancer in humans, as well as in animals, and are toxic to plants. Any disruption to the ozone layer can have devastating effects on living organisms.
Q4: What is the greenhouse effect? What is the impact of the greenhouse effect?
Answer:
Carbon dioxide and methane are examples of greenhouse gases that absorb solar energy and raise the temperature of the atmosphere. The term for this is the greenhouse effect. The greenhouse effect contributes to global warming.
Q5: Supersonic jets cause pollution by thinning of
(a) Sulphur dioxide layer
(b) Ozone layer
(c) Carbon dioxide layer
(d) None of these
Answer: (b) Ozone layer
Q6: Clouds are present in-
(a) stratosphere
(b) troposphere
(c) mesosphere
(d) thermosphere
Answer: (b) troposphere
Q7: Global warming is caused due to____ concentration of CO2 in the air
(a) Decreased
(b) Increased
(c) Both (a) & (b)
(d) None of these
Answer: (b) Increased
Q8: Which of the following gases can deplete the upper atmosphere’s ozone layer?
(a) Ammonia
(b) Carbon monoxide
(c) Methane
(d) Sulphur dioxide
Answer: (c) Methane
Q9: Air pollution causing photochemical oxidants production includes
(a) Carbon monoxide, sulphur dioxide
(b) Nitrous oxide, nitric acid fumes, nitric oxide
(c) Oxygen, chlorine, fuming nitric acid
(d) Ozone, peroxyacetyl nitrate, aldehydes
Answer: (d) Ozone, peroxyacetyl nitrate, aldehydes
Q10: CFCs are not recommended to be used in refrigerators because they
(a) Increase temperature
(b) Affect environment
(c) Deplete ozone
(d) Affect human body
Answer: (c) Deplete ozone
Q11: Is there an air pollution level that is safe for our health?
Answer:
Despite the fact that air pollution affects everyone’s health differently, there is no evidence of a totally acceptable amount of air pollution in large cities or countries, particularly with regard to particle matter. To assist nations in achieving healthier air quality, the WHO has established normative guideline values for all key air pollutants over which adverse health impacts are probable.
This does not imply that there are no health effects below these limits; rather, they are health-based targets that can be used to track the burden of disease caused by air pollution, inform national targets and standards, and measure the efficacy of air quality management efforts aimed at improving health.
In numerous nations, national air quality guidelines have been established. National standards may be higher or lower than the applicable WHO guideline value, depending on the country. A policy challenge is determining which specific populations at risk should be protected by the guidelines and what amount of risk is acceptable. In contrast, numerous nations are attempting to meet the WHO’s air quality criteria and intermediate targets.
Q12: Briefly describe the types of air pollution.
Answer:
There are two types of air pollution.
1. Man-made (Artificial) sources
These are mostly caused by the combustion of various types of fuel.
Smoke from power plants, industrial facilities (manufacturing enterprises), and waste furnaces, as well as incinerators and other fuel-burning heating equipment, are examples of stationary sources. In impoverished and emerging nations, the burning of traditional biomass is the leading cause of air pollution; traditional biomass includes wood, crop waste, and dung.
Movable sources comprise autos, aquatic vessels, and planes.
Controlled fire is sometimes employed in forest management, agriculture, and prairie restoration. Fire is a recognized component of both forest and grassland ecosystems, and foresters can use controlled fires as a tool. A precise fire ignites the growth of desired trees, so regenerating the forest.
Fumes from hairspray, paint, aerosol sprays, and other solvents are hazardous.
Methane is produced in landfills by waste dumps. Methane is highly combustible and can combine with air to generate an explosive and volatile mixture. Methane is also an asphyxiant that can displace oxygen in an enclosed space. If the oxygen concentration falls below 19.5% through displacement, suffocation may occur.
Military assets, including nuclear weapons, poisonous chemicals, germ warfare, and rocketry
2. natural origins
- Soil is derived from natural sources, often large tracts of land with few plants.
- Methane, released through the breakdown of food (digestion) by animals such as cattle, is a potent greenhouse gas.
- CO2 and smoke from forest fires.
- Volcanic activity releases sulfur, chlorine, and ash particles.
- Major Causes of Air Pollution Effects
- Air pollution has a devastating impact on humans and the environment. The ingredients may be solids, liquids, or gases. Contamination may be natural or synthetic. Primary contaminants are distinguished from secondary contaminants.
Typically, carbon dioxide emissions from vehicles and factories are the source of primary impurities. Secondary pollutants are pollutants that are not directly discharged into the atmosphere. They are produced in the atmosphere when primary pollutants combine or react. Ozone at ground level is a significant example of a secondary pollutant.
Some contaminants may be both primary and secondary, meaning that they are both directly emitted and generated from primary pollutants.
Q13: Is acid rain air pollution?
Answer:
Certain air pollutants create acid rain, a topic that attracted considerable attention in Europe and North America during the 1980s and 1990s. Sulfur dioxide (SO2) and nitrogen oxides (NOx) react with water in the atmosphere to produce sulphuric acid and nitric acid, which fall to the ground as “acid rain.”
Acid rain has an effect on the environment by causing damage to plant leaves, decreasing plant yield, and depleting the soil nutrients that plants require to survive. The acidification of groundwater and river water is harmful to fish, insects, and other species that consume them.
According to reports, buildings and monuments have been damaged by acid rain. Stronger SO2 and NOx emission limits, such as the United States Clean Air Act of 1970, the Canada–United States Air Quality Agreement of 1991, and corresponding measures in Europe, have significantly reduced acid rain in North America and Europe. While acid rain has been less of a concern in Europe and North America, the issue persists in Asia.
Q14: What is Smog, and how is it created? Also, mention the types of smog.
Answer:
Smog is a sort of air pollution that impairs visibility. Smog is a portmanteau of the words smoke and fog and refers to opacified and odorous smoky fog. The term was created in the twentieth century.
This sort of air pollution is comprised of nitrogen oxides, sulfur oxides, ozone, smoke, and other particles. Smog created by humans is caused by coal combustion emissions, automobile emissions, industrial emissions, forest and agricultural fires, and photochemical reactions of these emissions. The reaction of pollutants from automobiles, factories, and industries with sunlight and the environment cause smog.
There are two types of smog:
- Classical smog – This is the most common type of smog seen in humid environments. Smoke, fog, and sulfur dioxide make up the mixture. This smog is also known as reducing smog since it helps to reduce pollution in the atmosphere.
- Photochemical smog – This form of smog can be found in both dry and sunny parts of the globe. Automobiles and factories release smoke, including hydrocarbons and nitrogen dioxide, which, when exposed to sunlight, form the main component of photochemical smog. This smog is also known as oxidizing smog because it has a high concentration of oxidizing agents.
Effects of photochemical smog
The main components of photochemical smog are ozone, nitric oxide, and peroxyacetyl nitrate (PAN). Ozone is a powerful eye irritant that causes serious health problems. High concentrations of ozone and nitric oxide induce headaches, chest pain, dryness of the throat, and trouble breathing, among the major drawbacks of air pollution. Metals, structural materials, and painted surfaces are corroded by photochemical pollution.
Prevention of photochemical smog
To reduce photochemical smog, we should keep an eye on the usage of hydrocarbons and nitrogen dioxide at the primary level, as well as ozone and PAN at the secondary level. When used in automobiles, catalytic converters minimize hydrocarbon and nitrogen dioxide emissions. As a result, pollution levels in the atmosphere are lowered.
Q15: What are the major air pollutants produced by humans? What are their effects?
Answer:
The major air pollutants produced by humans are as follows:
- Sulfur oxides (SOx)
- Nitrogen oxides (NOx)
- Carbon monoxide (CO)
- Carbon dioxide (CO2)
- Ammonia (NH3)
- Particulates
- Free radicals
- Metals
- Odors
- Radioactive compounds
- Chlorofluorocarbons (CFCs)
- Volatile organic compounds (VOCs)
When harmful particles are directly discharged into the atmosphere, they are classified as primary pollutants; secondary pollutants are the result of reactions that occur after the emission. The following are examples of secondary pollutants:
- Smog
- Peroxyacetyl nitrate
- Ground-level ozone (O3)
Indoor air pollution has been connected to radon, VOCs, lead paint, combustion particles, carbon monoxide, and asbestos, all of which have been associated with bad health. Air pollution causes respiratory problems, heart disease, and lung cancer, which are detrimental to one’s health.
Indoor and outdoor air pollution are responsible for around 3.3 million deaths worldwide, with children in developing nations being particularly prone to illness or disease.
