10-08-2012, 11:22 AM
respected sir
Im a student kindly help to make ppts on various general topics like basic science, social problems. i want material worth presentable in the class of 10th
Thank you
gaurav
10-08-2012, 11:22 AM
respected sir Im a student kindly help to make ppts on various general topics like basic science, social problems. i want material worth presentable in the class of 10th Thank you gaurav
21-06-2013, 04:25 PM
environment pollution
environment pollution.pdf (Size: 33.35 KB / Downloads: 26) Introduction Pollution is contamination by a chemical or other agent that renders part of the environment unfit for intended or desired use. These uses also and very importantly include all wildlife and ecological requirements to sustain life in all its natural forms. Pollution damages the Earth's land, water and air. It results in contamination of the earth’s environment with materials that interfere with human health, the quality of life, and the natural functioning of ecosystems (living organisms and their physical surroundings). It deserves emphasis that the environment also refers to the place where you live. Natural processes have released toxic chemicals into the environment throughout the history of the earth. Currently, the pollution generated by human activities presents the most serious problem. Air pollution An air pollutant is known as a substance in the air that can cause harm to humans and the environment. Pollutants can be in the form of solid particles, liquid droplets, or gases. In addition, they may be natural or man-made. Particulates of both natural and human origin also cause pollution. Smoke both natural from fires and human activities cause from industries and other sources are major and cause much damage. The chemicals that are most trouble-some in air pollution are formed in the atmosphere by gases. The pollutant introduced into the atmosphere in the largest quantities by human activity is carbon monoxide. Industrial or gray smog is considered the most serious type of air pollution. Smoke and oxides of that are released by burning coal and oil containing minor amounts of sulfur is the cause. Cause Air Pollution - Each year industrially developed countries generate billions of tons of pollutants. Many pollutants come from directly identifiable sources; for example, comes from electric power plants burning coal or oil. Principal stationary pollution sources include chemical plants, coal-fired power plants, oil refineries, petrochemical plants, nuclear waste disposal activity, incinerators, PVC factories, metals production factories, plastics factories, and other heavy industry. The increasing number of vehicles has also lead to an increase in Air Pollution, due to the harmful gases like Carbon Monoxide emitted from these vehicles. Effect Throughout the world the damage cause by air pollution is enormous. In money alone it represents a loss of billions of dollars each year. Many flower and vegetable crops suffer ill effects from air pollution caused by exhaust gases. Trees have been killed by pollution. Cattle have been poisoned. Air pollution causes rubber tires on automobiles to crack and become porous. Pollutants in the air make it hard for people to breathe causing lung disease. When it rains the chemicals in the air cause acid rain hurting the animals and plants Pollution Control There are various air pollution control technologies and land use planning strategies available to reduce air pollution. At its most basic level land use planning is likely to involve zoning and transport infrastructure planning. In most developed countries, land use planning is an important part of social policy, ensuring that land is used efficiently for the benefit of the wider economy and population as well as to protect the environment. Efforts to reduce pollution from mobile sources includes primary regulation (many developing countries have permissive regulations), expanding regulation to new sources (such as cruise and transport ships, farm equipment, and small gas-powered equipment increased fuel efficiency conversion to cleaner fuels. Water pollution It covers 71% of the earth's surface and makes up 65 % of our bodies. Everyone wants clean water-- to drink, for recreation, and just to enjoy looking at. If water becomes polluted, it’s lost its value to us economically and aesthetically, and can become a threat to our health and to the survival of the fish living in it and the wildlife that depends on it. Although some kinds of water pollution can occur through natural processes, it is mostly a result of human activities. We use water daily in our homes and industries. The used water of a community is called wastewater, or sewage. If it is not treated before being discharged into waterways, serious pollution is the result. Water pollution also occurs when rain water runoff from urban and industrial areas and from agricultural land and mining operations makes its way back to receiving waters (river, lake or ocean) and into the ground. Cause The wastewater and liquids from plants and factories are linked with nearby river water, which are polluted when they release disposal from these units. People in Developing/Undeveloped countries also pollute rivers by using the water in these rivers for washing clothes, utensils, bathing and other activities. Many companies dump their toxic waste in many rivers and lakes. Ships spill oil in oceans and rivers. People throw litter in water. Pollution control To keep our used water from spoiling our water resources, we have to remove the pollutants before the water gets back into the environment. Industries located in areas where they are not connected to a sewer can discharge directly into a waterway, but will need a permit, and will probably have to have their own treatment plants. Homes in non-urban areas that are not connected to a sewer are usually required by their town to have on-site treatment systems, which consist of a buried tank connected to a set of perforated pipes, embedded in gravel, which distribute the water into the soil. Noise pollution Noise is probably the most frequently forgotten of the environmental pollutants, yet its effects can be many and far-reaching. Noise pollution is unwanted human-created sound that disrupts the environment. Millions of people on all continents are exposed to unhealthy levels of noise live in areas where the daily average noise levels exceed the safe noise level of an average of 55 decibels. What is a truly safe level of noise is controversial; levels of between 55 and 65 dB have been used for planning purposes have been called "acceptable". Cause The overarching cause of most noise worldwide is generated by transportation systems, principally motor vehicle noise, but also including aircraft noise and rail noise. Besides transportation noise, other prominent sources are office equipment, factory machinery, appliances, power tools, lighting hum and audio entertainment systems. Other sources include the noise in occupational settings or even the noise of simultaneous conversations. It also seems from a number of studies that intermittent noise is more of a problem than noise of a similar intensity which is constant. The machines used in factories make noise throughout the day, and this disturbs the peaceful atmosphere in the vicinity, as machines used without proper covering lead to sound pollution. This puts heavy mental strain on the people staying in the nearby areas. Noise is the most pervasive pollution in America. Land pollution Land pollution is where our land may be as far as being contaminated. All of the bad toxic chemicals and waste, that is left or dumped on our land, causes it to become polluted. All types of waste can be found on land. Some is left behind after human activities and some is washed ashore from boats and sewage outlets. Also, acid rain can pollute our land. Cause We are creating too much waste due to in particular to much unnecessary packaging. In addition to this, we do not adequately recycle the waste we create. Many of the resources we use in our everyday lives are disposed of quickly. Food is wrapped in paper or plastic bags, drinks are in throw-away bottles or cans, batteries are disposed of after a short life Pollution sources include chemical plants, coal-fired power plants, oil refineries, nuclear waste disposal activity, large animal farms, metals production factories, plastics factories, and other heavy industry. Landfills are also the source of many chemical substances entering the soil environment. With the rising standards of living, we are throwing away more things and there is an increase in the quantity of solid waste. |
|