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Air pollution

  1. Air Pollution By- Anup Muni Bajracharya
  2. Air Pollution • Defination • Undesirable, unwanted changes in the physical, chemical and biological characteristics of air that have adverse effects on biotic community like Human, plants and animals. • “the presence of one or several substances in the external atmosphere, introduced by man to such an extent as to effect health and welfare of human system and the life in the atmosphere.”
  3. Types of Air Pollutants • There are two types of air pollutants: Primary Pollutants • The pollutants that directly cause air pollution are known as primary pollutants. Sulphur-dioxide emitted from factories is a primary pollutant. Secondary Pollutants • The pollutants formed by the intermingling and reaction of primary pollutants are known as secondary pollutants. Smog, formed by the intermingling of smoke and fog, is a secondary pollutant.
  4. Sources • Air pollution mainly caused by human activities, even though sometimes it can result from Natural phenomena such as volcanic eruptions, dust storms and wildfires • Anthropogenic air pollution sources are: • 1. Combustion of fossil fuels • 2. Emissions from industries and factories • 3. Domestic sources • 4. Agricultural activities • 5. Waste production volcanic eruptions Forest fires
  5. 1. Emissions from industries and factories Fluoride, Nitric acid, Iron-steel, Chloro- alkali, Cement, Mineral acid plant and industries are most common sources of air pollutants. These emits a variety of pollutants in the atmosphere specially oxides of carbon, nitrogen, and sulphur. The metallurgical industry: high- temperature processing of ores emit aerosols rich in trace elements (Cd, Cu, Ni, Pb, V, and Zn). •Other industrial processes: high- temperature processing and manufacturing ( Cr, Cu, Ni, Pb, and Zn) •Transport: road traffic (Cd, Cu, Fe, Ni, Pb, and Zn), erosion of brake pads (Cu, and Sb), erosion of train rails (Cu) •Waste treatment: incineration of household waste (As, Cr, Cu, Ni, Pb, Sb, Se, V, and Zn)
  6. 2. Automobiles/Vehicles Gasoline used in automobiles as fuel produces carbon- monooxide, hydrocarbons, lead compounds, carbon particles and some carbonyl compounds in the atmosphere. They are the major source of air pollution.
  7. Automobile Pollutants • i. Hydrocarbons: • A class of burned or partially burned fuel, hydrocarbons are toxins and are a major contributor to smog, which can be a major problem in urban areas. • ii. Carbon monoxide (CO): • A product of incomplete combustion, carbon monoxide reduces the blood’s ability to carry oxygen. • iii. Nitrogen oxides (NOx): • Generated when nitrogen in the air reacts with oxygen at the high temperature and pressure inside the engine. • iv. Particulate matter: • Soot or smoke made up of particles in the micrometre size range: • v. Sulfur oxide (SOx): • A general term for oxides of sulphur, which are emitted from motor vehicles burning fuel containing a high concentration of sulphur.
  8. 3. Domestic sources- Combustion of fuels Domestic combustion of fuels result in the emissions of CO2, CO, and NO fueled by wood, agricultural residues, and dung. 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.
  9. 4. Agricultural activities A range of pollutant gases, and especially nitrogen compounds (NO2, NO, NH3, N2O) are emitted to the atmosphere from agricultural activities, including fertilizer use, farm machinery and livestock waste Burning of crop residues Fertiliser releases ammonia which mixes with the pollution from traffic, gas burning and industry
  10. 5. Waste treatment-burning/incineration • Open waste burning gave the following emissions to the atmosphere: • Carbon monoxide (CO) • PM (soot and ash) • Aldehydes • Polycyclic Aromatic Hydrocarbons (PAH)
  11. Others… • Thermal power plants thermal power plants of are main source of dust, carbon oxide, aldehydes, carbon, hydrocarbon, ash etc. are the common emission of power plants. • 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. • Other sources solid wastes, radio-active natural sources, viable particles, odour pollutants etc.
  12. Effects of Air Pollution • The hazardous effects of air pollution on the environment include: • Diseases • Global warming • Ozone depletion • Acid rain
  13. Diseases • Diseases caused by air pollutants kill and hospitalize millions of people every year. • Estimates by the World Health Organization imply that one out of every eight deaths in the world is due to conditions associated with air pollution. • New research has established stronger links between both outdoor and indoor air pollution and the development of respiratory and cardiovascular diseases. • The most common diseases caused by air pollution include • ischemic heart disease/coronary heart disease, • stroke, • chronic obstructive pulmonary disease (COPD), • lung cancer and • acute lower respiratory infections in children.
  14. Ischemic heart disease, or coronary heart disease, is linked with the buildup of calcium or other materials like fat within the coronary artery. This leads to blockages which prevent blood from reaching the heart and other areas of the body. COPD refers to not a single disease, but multiple diseases which make it difficult to breathe. These diseases include bronchitis and emphysema, and both conditions can be caused by damage to the lungs from air pollutants. Diseases
  15. Lung cancer is the uncontrolled division of cells within the lungs, and it is associated with air pollutants, especially particulate matter pollution, and secondhand smoke. “Particulate air pollution has been linked with strokes, which occur when the blood supply to the brain is cut-off. Strokes can easily lead to brain damage or death. Children are especially vulnerable to developing acute lower respiratory tract infections because their bodies and lungs are still developing, and emissions of soot and other pollutants hit them harder than adults. Diseases
  16. Global warming Global warming is a phenomenon of climate change characterized by a general increase in average temperatures of the Earth, which modifies the weather balances and ecosystems for a long time. It is directly linked to the increase of greenhouse gases in our atmosphere, worsening the greenhouse effect
  17. Green house effect Global warming occurs when carbon dioxide (CO2) and other air pollutants collect in the atmosphere and absorb sunlight and solar radiation that have bounced off the earth’s surface. Normally this radiation would escape into space, but these pollutants, which can last for years to centuries in the atmosphere, trap the heat and cause the planet to get hotter. These heat-trapping pollutants— specifically carbon dioxide, methane, nitrous oxide, water vapor, and synthetic fluorinated gases—are known as greenhouse gases, and their impact is called the greenhouse effect.
  18. Effects of Global Warming • Disappearing glaciers, early snowmelt, and severe droughts will cause more dramatic water shortages and continue to increase the risk of wildfires. • Rising sea levels will lead to even more coastal flooding A.B A.B
  19. Acid rain A.B
  20. Dead or dying trees are a common sight in areas effected by acid rain. Acid rain leaches aluminum from the soil. That aluminum may be harmful to plants as well as animals. Acid rain also removes minerals and nutrients from the soil that trees need to grow. Acid Rain Damages Buildings and Objects damaging effect on buildings, statues, monuments, and cars. can cause paint to peel and stone statues to begin to appear old and worn down, which reduces their value and beauty. Acid Rain Damages Lakes and Streams-pH low Acid Rain Can Cause Health Problems in People-asthma,bronchitis Effects of Acid rain
  21. Ozone depletion
  22. How CFCs destroys Ozone
  23. Effects of ozone depletion A.B
  24. Preventive measures • Prevention methods can either come from government (laws) or by individual action. • Public awareness programs should be launched. • The alternative source of energy like solar energy, wind energy, electric energy etc. should be used in place of fossil fuels like coal, wood, oil etc. • In industries the air filtration technique should be used. • Legislative actions by government. • Population growth rate should be controlled. • Plantation should be done. • The use of cheap fuel with higher sulphur content should be avoided. • Use of public vehicles or eco-friendly vehicles.