UNIT 1.pptx
- 2. 1. INTRODUCTION 2. METEOROLOGY 3. CONTROL OF PARTICULATE CONTAMINANTS 4. CONTROL OF GASEOUS CONTAMINANTS 5. INDOOR AIR QUALITY MANAGEMENT
- 3. Unit – 1 INTRODUCTION Structure and composition of atmosphere - Definition, scope and scales of air pollution - Sources and classification of air pollutants and their effect on human health, vegetation, animals, property, aesthetic value and visibility - Ambient air quality and emission standards - Ambient and stack sampling and analysis of particulate and gaseous pollutants.
- 4. Earth’s atmosphere Layer of gases surrounding a planet Provides essential oxygen Provides medium for sound Shields solar radiation
- 5. Atmosphere It is a mixture of gases that forms a layer of about 500 km thick around the earth. Composition of Air – 78% Nitrogen, 21% oxygen, 1% carbon dioxide, water, other gases
- 7. Structure of the atmosphere (Zones) Troposphere Stratosphere Mesosphere Thermosphere (Ionosphere) Exosphere
- 8. Troposphere It is the lowermost layer of the atmosphere. Troposphere contains dust particles and water vapour. Surface layer - 30,000 ft Heated from below Bottom 10 – 15 km (Troposphere) are most important part in terms of weather and other aspects of Biogeochemical cycle Convection - weather, clouds form from rising air which cools by pressure drop, and clouds dissipate as air falls and heats.
- 9. Stratosphere Heated by ozone absorbing UV light UV breaks apart ozone into O2 + atomic oxygen - get energy release and heating. Higher altitudes efficiently absorbs UV at 200 and 350 nm. Lower altitudes less efficiently absorbs UV at 44 and 80 nm Temperature inversion - no convection, no weather. 7 – 30 miles
- 10. Mesosphere Mass of atmosphere 0.1% Density is too low for ozone chemistry to heat Get normal trend we saw in troposphere– lower T with increasese altitude. 30-50 miles
- 11. Ionosphere (Thermosphere) Density - low Space Shuttle orbits here, with little drag T can be very high; 4,000F. But no significant heat because density low. Heated by ionization by UV from the sun, and the solar wind.
- 15. Air Pollution Air pollution is defined as the introduction of chemical, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to natural environment/built environment to atmosphere. Tends to be injurious to human, odor, smoke, gas, mist, dust, animal or plant life, or property, or which unreasonably interferes with the comfortable enjoyment of life or property or conduct of business. A pollutant can be solid (large or sub-molecular), liquid or gas .
- 17. Types of air pollution Personal air exposure (dust, fumes and gases – smoking) Occupational air exposure (aerosols, vapors, and gases – in working environment) Community air exposure ( meteorological factors, & wide variety of adverse social economical and health effects)
- 18. Scope and scales of air pollution Air pollution problems may occur on three scales: i. Micro scale (covering less than cm to size of a house or slightly larger – few meters to 100s of meter) ii. Meso – scale (few hectares up to the size of city or country – local to regional) iii. Macro scale (problems extend from countries to states, nations and in the broadest sense, globe (regional to continental scale)
- 21. Sources of Air Pollution Air Pollution may originate from a natural or anthropogenic source or from both sources. E.g. of natural source – an erupting volcano, accidental fire, etc., Types of Sources Mobile sources – such as cars, buses, planes, trucks, and trains Stationary sources – such as power plants, oil refineries, industrial facilities, and factories Area sources – such as agricultural areas, cities, and wood burning fireplaces Natural sources – such as wind-blown dust, wildfires, and volcanoes
- 24. Effect of air pollution on human health Air pollution : one of the greatest “ENVIRONMENTAL EVIL”. The air we breathe has not only LIFE SUPPORTING properties but also LIFE DAMAGING properties. An average man breathes 22,000 times a day and takes in 16 kg of air each day. All the impurities in the inhaled air do not necessarily cause harm. Some may be harmful when present in air – small concentration and others only if they are present in high concentration.
- 25. Factors affecting human health Nature of pollutants Concentration of the pollutants Duration of exposure State of health of the receptor Age group of the receptor
- 26. Target organ systems of air pollution
- 27. Effects of air pollution in human health Acute effects Chronic effects Acute effects: are usually immediate and often reversible when exposure to the pollutant ends. Some acute health effects includes eye irritation, headaches and nausea. Chronic effects: are usually not immediate and tend not to be reversible when exposure to the pollutant ends. Some chronic effects include decreased lung capacity and lung cancer resulting from long-term exposure to toxic air pollutants.
- 31. Effects of Air Pollution Reduced lung functioning Irritation of eyes, nose, mouth and throat Asthma attacks Respiratory symptoms such as coughing and wheezing Increased respiratory disease such as bronchitis Reduced energy levels Headaches and dizziness Disruption of endocrine, reproductive and immune systems Neuro behavioural disorders Cardiovascular problems Cancer Premature death
- 32. Effect of Air Pollution on Vegetation Air pollutants affect plants worldwide. These effects may be severe or subtle. Various sir pollutants have been identified as phytotoxic agents. Effects of ozone (O3) for more than 30 years. Acidic precipitation for almost 20 years.
- 33. Effects on Vegetation Injury vs Damage Injury: An observable alteration in the plant when exposed to air pollution Damage: An economic or aesthetic loss due to interference with the use of a plant
- 35. Pollutant deposition to plants Pollutants can to deposited to plants as Gases Wet precipitation Particulate matter Gaseous pollutants may be taken up by plants via Stomata or Cuticle The effects of pollutants can be observed at various levels of biological organs like: Subcellular Cellular Plant organ Whole plant Plant population community
- 36. Effects of Air Pollutants On Plants Under field conditions detection of physiological changes in plants and identification of their causes is difficult. Therefore visible symptoms of injury are most commonly used for detecting air pollution damage. However, changes in physiological of plants may occur before visible, morphological damage takes place.
- 37. Injury Injury - Generally, pollution injury first appears as leaf injury. Spots between the veins, leaf margin discoloration, and tip burns are common.
- 38. Two ways of pollutant entrance to plant Direct way: Through stomates which open and close to allow air through the interior parts. Indirect way: Through the root system. Pollutants deposit in soil and water and these pollutants were taken by the roots of the plant.
- 39. Common symptoms of damage on plants due to air pollution Yellowing of leaf Burning Stunted growth Premature leaf drop Early drop of blossoms Reduced yield or quality
- 43. Effects on materials Effects on metals Rusting Chemical attack on surface Corrosion due to moisture, temperature and pollutants Alteration of electrical properties
- 44. Effects on stone Discoloration Blackening Gypsum formation Cracking
- 45. Effect of air pollution GLOBAL WARMING Global warming is largely caused by increasing CO2 and other heat trapping gases (e.g. methane) in the atmosphere. Large amount of heat trapped on Earth; Earth becomes hotter. It results in rise in sea levels, flooding of low-lying lands, melting of polar ice caps and changes in global climate. Measures to reduce global warming-use of fossil fuels (to reduce CO2 emission) Use tidal, wind and hydroelectric energy to generate electricity -use of solar energy.
- 46. Sources and classification of air pollutants and their effect on animals, property, aesthetic value and visibility
- 49. Ambient air quality and emission standards Ambient air quality criteria, or standards, are concentrations of pollutants in the air, and typically refer to outdoor air. The criteria are specified for a variety of reasons including for the protection of human health, buildings, crops, vegetation, ecosystems, as well as for planning and other purposes. Ambient air pollution is a broader term used to describe air pollution in outdoor environments. Poor ambient air quality occurs when pollutants reach high enough concentrations to affect human health and/or the environment.
- 51. Ambient and stack sampling and analysis of particulate and gaseous pollutants Ambient air quality measurement: Where the pollutant levels in the ambient atmosphere are measured. Stack sampling: It deals with the pollutants emitted from a source such as smoke stack and is known as stack sampling. Process of collecting and verifying emissions from industrial sources.