Chapter no 4 environmental pollution
- 1. CHAPTER NO . 4
- 2. • SUBTOPIC: • 1. CONCEPT OF POLLUTION • 2. TYPES OF POLLUTION A. AIR POLLUTION CAUSES, EFFECTS AND CONTROL MEASURES B. WATER POLLUTION CAUSES, EFFECTS AND CONTROL MEASURES C. SOIL POLLUTION CAUSES, EFFECTS AND CONTROL MEASURES
- 4. Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of chemical substances or energy, such as noise, heat or light. Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. • Pollutants A pollutant is a waste material that pollutes air, water, or soil. Three factors determine the severity of a pollutant: its chemical nature, the concentration, the area affected and the persistence.
- 5. What’s Environmental Pollution? Environmental pollution in any an undesirable change in physical,chemical, or biological characteristics of any component of the environment
- 11. Meaning of Air Pollution • Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and mold spores may be suspended as particles. Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's also called smog. Some air pollutants are poisonous.
- 14. Causes of Air Pollution • Any process that produces substances that are small and light enough to be carried in air, or are gases themselves, can contribute to air pollution. These sources can be natural or man-made and occur all at once or slowly over time. Sources can be localized, such as industrial complexes, or come from multiple producers, such as cars. They can be indoor or outdoor, and even if pollutants are present, this does not mean that they are dangerous to health, as long as they do not exceed safe limits set by organizations such as the U.S. Environmental Protection Agency.
- 15. • Combustion from Industry Almost all of the common air pollutants can be produced by industrial processes. Some of these are produced by combustion of fossil fuels that drive the industrial process, resulting in particulates, ozone and nitrogen oxides. • Transportation Emissions Common forms of transportation like cars, planes and ships generally use combustion to harness energy from fossil fuels. The combustion process releases pollutants into the air, such as particles and carbon monoxide, and also releases substances that quickly form into nitrogen oxides and ozone, which are important air pollutants.
- 16. • Agriculture Side-Effects Farmers use machinery driven by fossil fuels to plow fields and harvest produce, and the animals that are raised in bulk for food also produce their own type of air pollution. Methane is a gas that contributes to the greenhouse effect that allows global warming; it arises from intestinal gas released by livestock. • Home Heating Keeping homes warm is commonly the job of fossil fuels such as oil, gas and coal. Their combustion means that heating is an important source of air pollutants like sulfur dioxide. If electricity is used to heat the house, the energy plants that produced it may also have been driven by fossil fuels.
- 17. • Home Cooking The energy used in cooking may have come from energy plants, in which case the potential for air pollution has arisen earlier. Alternatively, such as in developing countries, home cooking requires direct burning of wood or coals, which produces the particulate pollution at the point of use. • Volcano Eruptions Sometimes people think of air pollution as entirely man- made. In fact, natural processes release lots of substances into the air that are classed as pollution. Sulfur dioxide is a major modern air pollutant, and according to National Geographic, volcanoes can release enough sulfur dioxide into the air to influence global cooling.
- 18. • Forest Fires Forest fires release pollutants into the air in the same way as fireplaces burning wood produce pollution. They produce fine smoke particles, which, according to the EPA, are small enough to be able to get into the lungs and damage the lungs and the heart. • Tobacco Smoke In the developing world, homes may have visible smoke coming from the fire that is used to cook and heat the home. In the developed world, tobacco smoke is commonly the only visible type of air pollution inside the house. Both types of indoor smoke are linked to respiratory diseases.
- 19. • Metal Smelting Specific industries produce particular air pollutant profiles, and the major source of metal pollution like lead is metal smelting, although niche uses of lead, such as in the manufacture of certain aviation fuels, also contribute. • Aerosols and CFCs Chlorofluorocarbons (CFCs) in aerosols were a major cause of ozone layer destruction, and their production was banned in the United States in 1995. Despite such bans worldwide, the U.S. National Library of Medicine says CFCs can last for a century in the atmosphere, where they continue to do damage. The ozone layer helps shield the planet from dangerous ultraviolet rays.
- 20. • Burning of Fossil Fuels The combustion of fossil fuels emits a large amount of sulphur dioxide. Carbon monoxide released by incomplete combustion of fossil fuels also results in air pollution. • Automobiles The gases emitted from vehicles such as jeeps, trucks, cars, buses, etc. pollute the environment. These are the major sources of greenhouse gases and also result in diseases among individuals.
- 21. • Mining Activities In the mining process, the minerals below the earth are extracted using large pieces of equipment. The dust and chemicals released during the process not only pollute the air, but also deteriorate the health of the workers and people living in the nearby areas. • Domestic Sources The household cleaning products and paints contain toxic chemicals that are released in the air. The smell from the newly painted walls is the smell of the chemicals present in the paints. It not only pollutes the air but also affects breathing.
- 23. Effects of Air Pollution • The hazardous effects of air pollution on the environment include: • Diseases Air pollution has resulted in several respiratory disorders and heart diseases among humans. The cases of lung cancer have increased in the last few decades. Children living near polluted areas are more prone to pneumonia and asthma. Many people die every year due to the direct or indirect effects of air pollution. • Global Warming Due to the emission of greenhouse gases, there is an imbalance in the gaseous composition of the air. This has led to an increase in the temperature of the earth. This increase in earth’s temperature is known as global warming. This has resulted in the melting of glaciers and an increase in sea levels. Many areas are submerged underwater. • Acid Rain The burning of fossil fuels releases harmful gases such as nitrogen oxides and sulphur oxides in the air. The water droplets combine with these pollutants, become acidic, and fall as acid rain which damages human, animal and plant life.
- 24. • Ozone Layer Depletion The release of chlorofluorocarbons, halons, and hydro chlorofluorocarbons in the atmosphere is the major cause of depletion of the ozone layer. The depleting ozone layer does not prevent the harmful ultraviolet rays coming from the sun and causes skin diseases and eye problems among individuals. • Effect on Animals The air pollutants suspend on the water bodies and affect the aquatic life. Pollution also compels the animals to leave their habitat and shift to a new place. This renders them stray and has also led to the extinction of a large number of animal species.
- 25. • Accelerated Global Warming. This is a green energy discussion, so let’s tackle this one first. Earlier on, you learned about the Ozone layer and its role in protecting our planet. Air pollution directly accelerates the rate at which global warming happens by depleting the Ozone layer. Global warming refers to the increased temperatures Earth continues to experience. These higher temperatures lead to the melting of the polar ice caps and icebergs, which elevates sea levels and creates concern for the human race. • Human Respiratory and Heart Concerns. Air pollution is known to cause irritation in the eyes, lungs, nose, and throat. It creates respiratory problems and exacerbates existing conditions such as asthma and emphysema. When continually exposed to air pollution, humans become at higher risk for cardiovascular disease. Air filled with toxins can have a number of adverse effects on the arteries, and have even been a contributor to heart attacks.
- 26. • Wildlife Endangerment. Most diseases and conditions that humans are susceptible to, animals are as well. Air pollution creates many of the same issues that humans face. Heavily polluted areas force inhabitants to seek new homes, which can negatively impact the ecosystem. Toxic chemicals, which we’ll discuss in the next bullet, also deposit over surfaces of water that can lead to the endangerment of marine life animals.
- 27. Air Pollution Control Following are the measures one should adopt, to control air pollution: 1.Avoid Using Vehicles People should avoid using vehicles for shorter distances. Rather, they should prefer public modes of transport to travel from one place to another. This not only prevents pollution, but also conserves energy. 2.Energy Conservation A large number of fossil fuels are burnt to generate electricity. Therefore, do not forget to switch off the electrical appliances when not in use. Thus, you can save the environment at the individual level. Use of energy- efficient devices such CFLs also controls pollution to a greater level.
- 28. 3. Use of Clean Energy Resources The use of solar, wind and geothermal energies reduce air pollution at a larger level. Various countries, including India, have implemented the use of these resources as a step towards a cleaner environment.
- 29. Other air pollution control measures include: 1. By minimizing and reducing the use of fire and fire products. 2. Since industrial emissions are one of the major causes of air pollution, the pollutants can be controlled or treated at the source itself to reduce its effects. For example, if the reactions of a certain raw material yield a pollutant, then the raw materials can be substituted with other less polluting materials. 3. Fuel substitution is another way of controlling air pollution. In many parts of India, petrol and diesel are being replaced by CNG – Compressed Natural Gas fueled vehicles. These are mostly adopted by vehicles that aren’t fully operating with ideal emission engines. 4. Although there are many practices in India, which focus on repairing the quality of air, most of them are either forgotten or not being enforced properly. There are still a lot of vehicles on roads which haven’t been tested for vehicle emissions.
- 30. 5. Another way of controlling air pollution caused by industries is to modify and maintain existing pieces of equipment so that the emission of pollutants is minimized. 6. Sometimes controlling pollutants at the source is not possible. In that case, we can have process control equipment to control the pollution. 7. A very effective way of controlling air pollution is by diluting the air pollutants. 8. The last and the best way of reducing the ill effects of air pollution is tree plantation. Plants and trees reduce a large number of pollutants in the air. Ideally, planting trees in areas of high pollution levels will be extremely effective.