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In The Name Of Allah, Most Gracious, Most Merciful. Air Pollution; Sources, Effects, Prevention & Control.
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Environmental Pollutionis “The contamination of the physical and biological components of the atmospheric system to such an extent that normal environmental processes are adversely affected”. • Types of Environmental Pollution There are three major types of environmental pollution: • Air Pollution • Water Pollution • Soil Pollution (Contamination)
AIR POLLUTION • Air pollution is a release into the atmosphere of any substances, ex. chemicals or airborne particles, which are harmful both to the human and animal health as well as the health of the wider environment.
CAUSES OF AIR POLLUTION • Natural Causes • Forest Fires • Volcanic Eruptions • Vegetation Decay Processes In Soil. • Anthropogenic (Human-made) Causes • Burning of Fossil Fuels (Oil, Gas & Coal)
FUNDAMENTAL CAUSES OF AIR POLLUTION • Industrialization Industrialization set in motion the widespread use of fossil fuels which are now the main drivers of pollution. • Population Growth It causes the demand for food and other goods to go up, which is met by expanded production and use of natural resources. This then leads to higher levels of atmospheric pollution. • Globalization Globalization has in a way become a facilitator of air pollution. Big industry takes advantage of negligent environmental controls in developing nations and moves its manufacturing facilities to such “pollution havens” from where air pollution travels around the world without any obstacles.
Combustion Engine Exhaust The exhaust from vehicles contains carbon monoxide, nitrous oxide and gaseous oxide. This type of air pollution creates smog. • Petroleum Refineries Petroleum refineries release hydrocarbons and various particulates that pollute the air. • Chemicals Pesticides, insecticides, fertilizers and herbicides all cause air pollution.
Radioactive Fallout Radioactive fallout from the nuclear power plants also causes air pollution. • Indoor Air Pollution This happens when there is not enough ventilation to disburse the toxic fumes produced in homes. Sources of indoor air pollution include Biological contaminants like mold, tobacco smoke, Household products and pesticides.
AIR POLLUTANTS • Sulfur Dioxide (SO2) The main sectors producing sulfur dioxide are: • Power Generation and Refineries • Manufacturing industry • Nitrogen Oxides (NOx) The main sectors producing nitrogen dioxide (NO2) are: • Road Transport • Deforestation & Fires • Carbon Dioxide (CO2) Major sources of CO2 are Fossil Fuels Burning and Deforestation. • Chlorofluorocarbons (CFCs) Chlorofluorocarbons are greenhouse gases that contribute to global warming.
Carbon Monoxide (CO) The top sectors producing carbon monoxide are: • Biofuel Combustion • Agriculture Waste Burning • Ammonia (NH3) • Agriculture, specifically livestock farming & animals waste, is the main source of ammonia emissions.
LEGAL REGULATIONS In general, there are two types of air quality standards. • The first class of standards (such as the National Ambient Air Quality Standards) set maximum atmospheric concentrations for specific pollutants. • The second class (such as the Air Quality Index) take the form of a scale with various thresholds, which is used to communicate to the public the relative risk of outdoor activity.
AIR QUALITY INDEX (AQI) • The Air Quality Index (AQI) is a number used by government agencies to characterize the quality of the air at a given location. As the AQI increases, an increasingly large percentage of the population is likely to experience severe adverse health effects. • To compute the AQI requires an air pollutant concentration from a monitor or model. • Air quality index values are divided into ranges, and each range is assigned a descriptor and a color code.
Each air pollutant exerts their own specific adverse impacts, ranging from mild to really damaging. • We can distinguish between short-term acute effectsand long-term chronic effects of air pollution. • Air pollutants enter the body primarily through the respiratory system which thus becomes their main victim.
Effects of Air Pollution • Effects on Humans • Effects on Animals • Effects on Trees • Economic Losses • Effects of Smog • Effects of Acid Rain • Global Warming and Air Pollution
Effects on Humans • Sulphur Dioxode • Nitrogen Dioxide • Carbon monoxide • Ozone • Ammonia • Volatile Organic Compounds • Airborne Particles
Effects on Humans • Sulphur Dioxide Effects: Asthma sufferer • Irritation of eyes, nose, throat; • damage to lungs when inhaled • Acute and chronic asthma • Lung cancer
Effects on Humans • Nitrogen Dioxide Effects: • Increased incidence of respiratory illness • Increased airway resistance (due to inflammation) • Damage to lung tissue • Nitrogen dioxide affects people with existing medical conditions more severely than healthy people. Children are affected easier than adults.
Effects on Humans • Carbon Monoxide Effects: • Toxicity of the central nervous system and • heart • Headaches, dizziness, nausea and unconsciousness • Loss of vision • Decreased muscular coordination • Abdominal pain
Effects on Humans • Ozone Effects: • Burning nose and watering eyes • Coughing, wheezing and throat irritation • Rapid, shallow, painful breathing • Susceptibility to respiratory infections • Inflammation and damage to the lining of the lungs • Aggravation of asthma • Fatigue • Cancer
Effects on Humans • Ammonia Effects: • On the respiratory system : • Nose & throat irritation and burns • Swelling of the throat and airways; airways destruction • Chronic lung disease • Cough • Asthma • Inhaling large amounts of ammonia can be fatal • On the skin & eyes : • Skin burns • Skin conditions, ex. dermatitis • Burning sensation in the eyes • Ulceration & perforation of the cornea (can occur months after exposure); blindness • Cataracts & glaucoma
Effects on Humans • Effects of Volatile Organic Compounds: • Tiredness, dizziness, nausea, confusion, unconsciousness • Anemia • Bone marrow damage • Liver damage • Dysfunction of the central nervous system: • Behavioral problems • Memory loss • Disturbance of the circadian rhythm • Cardiovascular diseases • Cancer; specifically leukemia • As facilitators in ozone formation, VOCs may indirectly contribute to respiratory problems
Effects on Humans • Effects of Airborne Particles: • Stuffy noses, Sore throats , Wet cough, dry cough • Head colds • Burning eyes • Wheezing; shortness of breath • Children are of course more susceptible to particulate pollution. • Specific children’s disorders caused by airborne particles may include: • Infant death • Low birth weight • Reduced lung function
Effects on Animals • Acid rain contains much higher than normal amount of sulphuric and nitric acid i-e actually toxic to aquatic life in lakes and streams. • This poses threat to aquatic life as well as the food chain in general. It is also harmful to plants and degrades buildings and monuments.
Effects on Animals Pollution may affect animals through plants on which they feed. For example, if a certain plant is negatively affected by air pollutants, this will also affect the animals that depend on this particular plant for food. Tropospheric ozone may damage animal lung tissue.
Effects on Trees and Plants Here is how sulphur dioxide may affect trees & plants : • Cell metabolism disruption (membrane damage, respiration and photosynthetic effects) • Leaf injury and loss • Reduced growth and reproduction • Increase in susceptibility of plants to attacks by insect herbivores • Particulate air pollution effects on plants & trees may include : • Blocked stomata • Increased leaf temperature • Reduced photosynthesis • Reduced fruit set, leaf growth, pollen growth • Reduced tree growth
Effects on Trees and Plants • Acid rain (as a product of sulphur and nitrogen pollution) can kill trees, destroy the leaves of plants, can infiltrate soil by making it unsuitable for purposes of nutrition and habitation. • It is also associated with the reduction in forest and agricultural yields.
Air Pollution Effects – Economic Losses Some of these economic effects are : • Direct medical losses • Lost income from being absent from work • Decreased productivity • Travel time losses due to reduced visibility • Losses from repair of damage to buildings • Increased costs of cleaning • Losses due to damage to crops & plants
Effect Of Smog • Though "smog" is sometimes described as a combination of smoke and fog, it is actually a mixture of pollutants and ground-level ozone. • The pollutants that help make smog come mostly from vehicle emissions, factories, power plants and consumer products like paint and solvents. • Smog can cause problems such as respiratory ailments, reduced visibility, damage to vegetation, colds, and eye irritation.
Depletion of Ozone Layer • Over the years, the constant use of industrial and domestic chemical, mostly CFC's used in refrigerators and other solvents have depleted an area of this layer. • This area is found over an ice shelf in Antarctica and the ice caps are melting with the result of a rise in sea level. This depletion is causing global warming or the greenhouse effect.
Global Warming and Air Pollution • Effects of global warming :- Sea temperatures would increase, the water would enlarge and the sea levels rise. - Low-lying areas would be flooded. Some islands would disappear altogether. - Hot regions could become hotter and deserts would extend. - Some plants and animals would become extinct
Global Warming and Air Pollution Is Climate Change Making Us Sick?More floods, heat waves, insect-borne disease... Global warming affecting our health badly. Every one degree rise means 75 deaths Deaths can be caused by the body’s inability to adapt and cool itself sufficiently. However, the main causes of death and illness are cardiovascular and respiratory disease.
Air Pollution; Prevention Awareness • In many countries in the world, steps are being taken to stop the damage to our environment from air pollution. • Scientific groups study the damaging effects on plant, animal and human life. • Legislative bodies write laws to control emissions. • Educators in schools and universities teach students, beginning at very young ages, about the effects of air pollution.
Solution to Air Pollution Problem.. • The first step to solving air pollution is assessment . Researchers have investigated outdoor air pollution and have developed standards for measuring the type and amount of some serious air pollutants. • Scientists must then determine how much exposure to pollutants is harmful. • Once exposure levels have been set, steps can be undertaken to reduce exposure to air pollution. These can be accomplished by regulation of man-made pollution through legislation.
Control through Legislation • Many countries have set controls on pollution emissions for transportation vehicles and industry. • This is usually done to through a variety of coordinating agencies which monitor the air and the environment.
PEPA • Pakistan Environmental Protection Agency is an attached department of the Ministry of Environment and responsible to implement the Pakistan Environmental Protection Act, 1997 in the country. • An Act to provide for the protection, conservation, rehabilitation and improvement of environment, for the prevention and control of pollution, and promotion of sustainable development. • It has set the NEQS; to monitor and control Environment Pollution levels.
Reduction in Air Pollution • Reductions in air pollution can be achieved by a variety of methods including pollution prevention, control technologies, and control measures. • A control strategy may include a combination of different voluntary measures or mandatory controls, and may focus on one or several pollutants or sources of air pollution.
Control of Emissions • Air pollution control technologies have achieved stunning results in reducing emissions from the manufacturing and mobile source sectors by as much as 90 to 99 percent. • Mercury and Other Toxic Air Pollutants • Ozone • Particle Pollution
Mercury and Other Toxic Air Pollutants • Control of mercury emissions is based upon reduction of the emissions and pollutant releases into the atmosphere by the industries that use mercury within their processes, emit mercury or dispose of products containing mercury, such as thermometers. • Emission standards for hazardous air pollutants have been established for industries emitting toxic air emissions.
Mercury and Other Toxic Air Pollutants • Strategies for controlling mercury and other toxic air pollutants include; • Product Substitution, • Process Modification, • Work-Practice Standards, • Materials Separation; • Coal Cleaning (relevant to mercury control); • Flue Gas Treatment Technologies; and alternative strategies. • Significant sources of toxic air pollution are motor vehicles, so programs to reduce emissions from cars, trucks and buses also decrease concentrations of toxic air pollutants. These programs include; • Reformulated gasoline, • National low emission vehicle (NLEV) program, • Gasoline sulfur control requirements.
Ozone Depletion Control; NOx & VOCs • Ozone control strategies generally target nitrogen oxides (NOx) and volatile organic compounds (VOCs) • Control strategies may comprise a set of regulations that specify emission limits and control equipment like; • Reasonable Available Control Technology (RACT), • Best Available Control Technology (BACT), • Lowest Achievable Emission Rates (LAER).
Particle Pollution • Particle pollution, or particulate matter (PM) pollution control strategies reduce primary PM emitted directly by a source, or PM precursor emissions (NOx, SOx, VOC, and ammonia) that react in the atmosphere to form fine PM.
PM Contd • Control strategies could include a set of regulations that specifies emission limits. • PM control equipment or programs may address specific industrial processes, that burns diesel fuel, and sources such as dust from agricultural activities.
Effective Air Pollution Control Methods • Activated Carbon. • Bio filters; Clearing the Air. • Catalytic Oxidizers; Driving Towards Cleaner Emissions. • Acid Gas Control - SO2 ; Use of Wet or Dry Scrubbers.
Activated Carbon • It is a popular air pollution control method. One of the most common forms of carbon treatment in air pollution control is carbon adsorption. • This method sees the use of dry chemical scrubbing media such as carbon filters for the adsorption of fumes from the air.
Bio filters; Clearing the Air • Bio Filtration is a method of pollution control in which process pollutants are biologically degraded using micro-organisms. The most common application of bio filters is the micro biotic oxidation of contaminants in the air.
Catalytic Oxidizers; Driving Towards Cleaner Emissions. • Catalytic Oxidizers are placed in the exhaust system of cars to reduce emissions from the exhaust pipe. • The ideal byproducts of a car’s engine are carbon dioxide, some water and nitrogen. However in reality engines continue to release unburned hydrocarbons which damage the environment.
A BIG Problem!!! • Gas Flares: (or flare stacks) burning off unwanted substances and releasing them into the environment. • Examples of gas flare usage include chemical plants, landfills and oil rigs. Their most common purpose is to protect against unplanned over-pressuring of the plant equipment.