urban pollution - evs project

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urban pollutionDefinition: Pollution of highly populated areas mainly deriving from motor vehicles, industrial plants, combustion and heating plants, etc.

IntroductionAir quality is a significant environmental problem in urban areas of Mongolia, particularly in Ulaanbaatar. Primary sources of air pollution in Ulaanbaatar are three thermal power plants, about 200 sma ll and medium sized heating boilers, about 60,000 traditional gers and wooden houses, and over 40,000 automobiles Topography and meteorology exacerbated ambient air quality conditions in the country, and particularly in Ulaanbaatar. Mountains surround Ulaanbaatar up to 2,250 meters in height inhibited dispersion of pollutants To compound the s i t u a t ion, a s t a b l e atmosphe r i c inversion forms during the winter season. As a result, ambient pollutant concentrations often remained for days or weeks at a time to exceed Mongolian and other international ambient air quality standards. Burning of coal and woods in the households in urban cities has been identified as major sources of air pollution, which affects ambient air quality and human health.

In modern times pollution has become the biggest menace for the survival of the biological species. There are various types of pollution e.g. air, water, soil, sound and mental pollution. Earth was a beautiful landscape but man has ruthlessly exploited for his greed specially, in the last century. With rapid industrialization and random urbanization environmental pollution has become a serious problem. Over exploitation of open spaces, ever-increasing number of automobiles and demographic pressure have further aggravated the problem.

There are various ways and means to mitigate the urban environmental pollution. Plan-ting of trees and shrubs for abatement of pollution and improvement of environment is an effective way and well recognized throughout the world. Earlier, the purpose of planting trees in urban areas was purely aesthetic. The incessant increase of urban environ-mental pollution has necessitated to reconsider the whole approach of urban landscaping and its orientation in order to achieve duel effect i.e. bio-aesthetics and mitigation of pollution. Proper planning and planting scheme depending upon the magnitude and type of pollution, selection of pollution- tolerant and dust scavenging trees and shrubs should be done for bioremediation of urban environmental pollution. Pollution, the major problem in cities, is compounded by the fact that there is no exhaust for the polluted air to escape. Landscape architects can solve the pollution problems related to urban landscape by creating a microclimate. Planting along the road Roads are the important sites of the urban areas which contribute significantly in generating pollution. By planting trees on both sides pollution can be mitigated. Unfortunately, in most of the old Indian cities and towns, there is hardly any provision of sufficient space for the same. However, it is necessary to study the type of road, overhead electrical cables, spaces available on both sides, central verge, traffic triangles, round-abouts, squares and other open space available before taking up any plantation. It has been observed that trees and shrubs which are drought/frost resistant are generally tolerant to pollution. Selection of trees is another important task. Traffic Island Traffic islands at the main road intersections vary in shape and size from square, triangle to round. Whatever may be the shape, these islands should be properly planted with the dwarf trees, shrubs and ground covers recommended for planting along the road and central verge which will contribute effectively in mitigating the air pollution. Greenbelt Greenbelt is defined as the mass plantation of pollution tolerant trees and shrubs in an area for the purpose of minimizing air pollution by filtering, intercepting and absorbing pollutants in an effective manner for improvement of the environment. Every town and city must have certain area earmarked for the development of greenbelts. The effectiveness of the greenbelt depend on several factors viz. climatic conditions, design, selection of plant species and its characters and type of pollutants. The importance of greenbelt can be ascertained from the estimate of cleansing capacity of 3.7 tonnes of CO2 from atmosphere and supply of 2.5 tonnes of oxygen from one hectare of woodland

URBAN WATER POLLUTION.

ProblemUrban areas have the potential to pollute water in many ways. Runoff from streets carries oil, rubber, heavy metals, and other contaminants from automobiles. Untreated or poorly treated sewage can be low in dissolved oxygen and high in pollutants such as fecal coliform bacteria, nitrates, phosphorus, chemicals, and other bacteria. Treated sewage can still be high in nitrates. Groundwater and surface water can be contaminated from many sources such as garbage dumps, toxic waste and chemical storage and use areas, leaking fuel storage tanks, and intentional dumping of hazardous substances. Air pollution can lead to acid rain, nitrate deposition, and ammonium deposition, which can alter the water chemistry of lakes.

SolutionsSolutions involve finding sustainable ways for the urban area to reduce both its dependence on pollutants and the amount of pollutants it produces, and to properly recycle or dispose of pollutants before they contaminate soil, water, or air. See the discussion below under "Lakes that Face this Problem" for more detailed solutions that have been tried at various lakes. Preventing pollution in urban areas is often largely a public relations task. People need to be educated about proper ways to dispose of waste. Showing each other where waste goes and the problems it can create in our watersheds is an effective way to get the message across. Of course, regulations are often necessary to reduce the amount of pollutants contaminating our watersheds, and the Lake Biwa Ordinance is an example of regulatory measures (such as prohibiting synthetic detergents) making a big difference.

Pollution|Introduction |Air Pollution |Water Pollution |Land Pollution |

Introduction Pollution is the addition to the ecosystem of someting which has a detrimental effect on it. One of the most important causes of pollution is the high rate of energy usage by modern, growing populations. Different kinds of pollution are found. In this section we will discuss: 1. Air Pollution. 2. Water Pollution. 3. Land Pollution.

Air Pollution Air pollution is the accumulation in the atmosphere of substances that, in sufficient concentrations, endanger human health or produce other measured effects on living matter and other materials. Among the major sources of pollution are power and heat generation, the burning of solid wastes, industrial processes, and, especially, transportation. The six major types of pollutants are carbon monoxide, hydrocarbons, nitrogen oxides, particulates, sulfur dioxide, and photochemical oxidants.

Examples of Air Pollution

. Noise PollutionNoise pollution or unwanted sounds that are carried by the air, have an irritating and detrimental effect on humans and other animals. Careful planning of streets and biuldings in towns and better control over noisy vechiles may add to the control of noise pollution.

. Tobacco SmokeTobacco smoke is one of the major forms of pollution in buildings. It is not only the smoker who is infected, but everyone who inhales the polluted air. There is a very strong connection between smoking and lung cancer. Bronchitis is common among smokers and unborn babies of mothers who smoke also suffer from the harmful effects of smoking.

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Exhaust Gases of Vehicles Pollution from exhaust gases of vehicles is reponsible for 60% of all air pollution and in cities up to 80%. There is a large variety of harmful chemicals present in these gases, with lead being one of the most dangerous.

. Combustion of CoalThe combustion of caol without special precautions can have serious consequences. If winds do not blow away the poisonous gases, they can have fatal effects and may lead to death.

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Acid rain Acid rain is the term for pollution caused when sulfur and nitrogen dioxides combine with atmospheric moisture to produce highly acidic rain, snow, hail, or fog. The acid eats into the stone, brick and metal articles and pollutes water sources. Coal in South Africa is rich in sulphur and the power stations in the Mpumalanga Province could be reponsible for acid rain over other areas of our country. Control Measures Although individual people can help to combat air pollution in their own immediate environment, efficient control can be best achieved by legislation. Some commonly enforced control measures includey y

the establishment of more smokeless zones; control over the kinds of fuel used in cars, aeroplanes, power stations, etc.

Water Pollution Water pollution is the introduction into fresh or ocean waters of chemical, physical, or biological material that degrades the quality of the water and affects the organisms living in it. This process ranges from simple addition of dissolved or suspended solids to discharge of the most insidious and persistent toxic pollutants (such as pesticides, heavy metals, and nondegradable, bioaccumulative, chemical compounds).

Examples of Water Pollutiony

y

y

Industrial affluents Water is discharged from after having been used in production processes. This waste water may contain acids, alkalis, salts, poisons, oils and in some cases harmful bacteria. Mining and Agricultural Wastes Mines, especially gold and coal mines, are responsible for large quatities of acid water. Agricultural pesticides, fertilisers and herbicides may wash into rivers and stagnant water bodies. Sewage Disposal and Domestic Wastes Sewage as wel as domestic and farm wastes were often allowed to pollute rivers and dams.

Control Measures The following measures can be used to stop water pollution:y y

every intelligent people should be wise enough not to pollute water in any way; by research and legislation the pollution of water bodies, even though not entirely prevented, must be effectively controlled.

Land Pollution Land pollution is the degradation of the Earth's land surface through misuse of the soil by poor agricultural practices, mineral exploitation, industrial waste dumping, and indiscriminate disposal of urban wastes. It includes visible waste and litter as well as pollution of the soil itself.

Examples of Land Pollution Soil Pollution Soil pollution is mainly due to chemicals in herbicides (weed killers) and pesticides (poisons which kill insects and other invertebrate pests). Litter is waste material dumped in public places such as streets, parks, picnic areas, at bus stops and near shops. Waste Disposal The accumulation of waste threatens the health of people in residential areas. Waste decays, encourages household pests and turns urban areas into unsightly, dirty and unhealthy places to live in. Control Measures The following measures can be used to control land pollution:y y y

anti-litter campaigns can educate people against littering; organic waste can be dumped in places far from residential areas; inorganic materials such as metals, glass and plastic, but also paper, can be reclaimed and recycled.

Types and causes of urban stormwater pollution

Stormwater pollutants originate from many different sources ranging from fuel and oil from our roads, to litter dropped on our streets and sediment from building sites. There are three main types of stormwater pollution: y y y litter, for example cigarette butts, cans, food wrappers, plastic bags or paper 'natural' pollution, for example leaves, garden clippings or animal faeces chemical pollution, for example fertilisers, oil or detergents.

Below is a table of the common pollutants found in urban stormwater, their likely sources and the effect of the pollutant on our waterways.

Pollutant

Effect

Urban source

Sediment

Reduces the amount of light in the water available for plant growth and thereby reducing the supply of food for other organisms. Can clog and damage sensitive tissues such as the gills of fish. Can suffocate organisms which live on or in the bed of lakes and streams by forming thick deposits when this suspended material settles out.

y y y y y y y y

Land surface erosion Pavement and vehicle wear Building and construction sites Spillage, illegal discharge Organic matter (for example leaf litter, grass) Car washing Weathering of buildings/structures Atmospheric deposition. Organic matter Fertiliser Sewer overflows, septic tank leaks Animal faeces Detergents (car washing) Atmospheric deposition Spillage, illegal discharge.

Nutrients

An increase of nutrients in water stimulates the growth of aquatic plants. This causes excessive growth of aquatic weeds and algae that may choke lakes and streams and lead to dramatic daily fluctuations in dissolved oxygen levels.

y y y y y y y

Oxygen demanding substances

pH acidity

Oxygen is used up more y quickly than it can diffuse into the water from the atmosphere. y The resulting drop in oxygen y levels may then be sufficient to kill fish and other aquatic y organisms. If all the oxygen in the water is used up, unpleasant y odours can result. Increased acidity damages y plants and animals y y y

Organic matter decay Atmospheric deposition Sewer overflows, septic tank leaks Animal faeces Spillage, illegal discharges. Atmospheric deposition Spillage, illegal discharge Organic matter decay Erosion of roofing material. Animal faeces Sewer overflows, septic tank leaks Organic matter decay.

Micro-organisms

Contain very high numbers of y bacteria and viruses. Some of y these organisms can cause illnesses, including hepatitis y and gastroenteritis. y

Toxic organics

Can poison living organisms or y damage their life processes.

Pesticides Herbicides Spillage, illegal discharge Sewer overflows, septic tank leaks. Atmospheric deposition Vehicle wear Sewer overflows, septic tank leaks Weathering of buildings, structures Spillage, illegal discharges. Pedestrians and vehicles Waste collection systems Leaf-fall from trees Lawn clippings Spills and accidents. Asphalt pavements Spillage, illegal discharges Leaks from vehicles Car washing Organic matter.

y y yHeavy metals Poison living organisms or y damage their life processes in some other way. Persists in the y environment for a long time. y

y yGross pollutants (litter and debris) Unsightly. Animals can eat and y choke on this material.

y y y yOils, detergents and shampoos (surfactants) Highly toxic poison to fish and y other aquatic life.

y y y y

Increased water temperature

High temperatures are lethal to y fish and other aquatic organisms. Elevated water y temperatures stimulate the growth of nuisance plants and algae. This and other effects can lead to decreased levels of dissolved oxygen which can threaten other aquatic life.

Runoff from impervious surfaces Removal of riparian vegetation.

Why Do We Need Urban Air Quality Management?

On our planet, the air we breathe is one of the most important things around us. It is a vital natural resource on which all life depends. Clean air is something that we all need for good health and the wellbeing of humans, animals, and plants. Sadly, however, our atmosphere is being continuously polluted. Bad air quality affects human health as well as other environmental resources such as water, soil, and forests. Thus, air pollution also hampers development. Larger cities with highly concentrated industry, intensive transport networks and high population density are a major source of air pollution. Many cities around the world, particularly in developing countries, are experiencing rapid growth. Yet, in the absence of adequate environmental policy and action, this growth is occurring at a considerable, and often increasing, economic and social cost. More people, more industry, and more motor vehicles cause ever-worsening air pollution which poses aserious environmental threat in many cities. The World Health Organization (WHO) and other international agencies have long identified urban air pollution as a critical public health problem. Many developing countries and emerging economies, for example China, Indonesia, and Mexico, have therefore included air pollution into their list of priority issues to be tackled. The grave consequences of air pollution on public health are measured not only in terms of sickness and death, but also in terms of lost productivity and missed educational and other human development opportunities.

Thus, degradation of air quality not only hinders economic growth by imposing significant additional operating costs on business, industry, households, and public services it also means that the quality of life in these affectedcities is spiralling downwards. Likewise, air pollution accelerates deterioration of buildings and historic monuments. A reputation for bad air pollution certainly deters investments from the outside. Air pollution puts a strain on sustainable urban development, which includes economic growth, social inclusion, human well-being, and the environment.

Urban Planning and Air QualityThe role of urban planning is to manage the spatial organization of cities for efficient allocation of urban infrastructure and land use. Depending on how it is applied, urban planning can improve air quality in the long run by strategic location of polluting sources and exposed population, and encouraging a city structure that would minimize pollution emissions and build-up. Unfortunately, urban regulations in South Asia have historically contributed to misallocation of land use and growth of urban shapes that are not necessarily conducive to economic development or air quality improvement. Taking careful account of market forces and allowing demand driven solutions rather than the current administrative allocation of resources could bring considerable benefits, if closely coupled with other sector policies most notably in transport.