Land Pollution PDF

Land Pollution What is land pollution? It's the introduction into the environment of substances that don't normally belong there, which, in great enough concentrations, can have harmful effects on plants, animals, and humans. We can define land pollution either narrowly or...

Land Pollution What is land pollution? It's the introduction into the environment of substances that don't normally belong there, which, in great enough concentrations, can have harmful effects on plants, animals, and humans. We can define land pollution either narrowly or broadly. Narrowly defined, it's another term for soil contamination (for example, by factory chemicals or sewage and other wastewater). What is land pollution?  It more widely to include garbage and industrial waste, agricultural pesticides and fertilizers, impacts from mining and other forms of industry.  The unwanted consequences of urbanization, and the systematic destruction of soil through over-intensive agriculture; we'll take land pollution to mean any kind of long-term land damage, destruction, degradation, or loss. Causes of land pollution  There are many different ways of permanently changing the land, from soil contamination (poisoning by chemicals or waste) to general urbanization (the systematic creation of cities and other human settlements from green field, virgin land).  Some, such as huge landfills or quarries, are very obvious; others, such as atmospheric deposition (where land becomes contaminated when air pollution falls onto it). Waste Disposal  Humans produce vast quantities of waste—in factories and offices, in our homes and schools, and in such unlikely places as hospitals.  Even the most sophisticated waste processing plants, which use plasma torches (electrically controlled "flames" at temperatures of thousands of degrees) to turn waste into gas, produce solid waste products that have to be disposed of somehow.  There's simply no getting away from waste: our ultimate fate as humans is to die and become waste products that have to be burned or buried! Examples of land Pollution 5 Examples of land Pollution 6 7 Examples of land Pollution 8 Mining  Although there are many responsible mining companies, and environmental laws now tightly restrict mining in some countries, mines remain among the most obvious scars on (and under) the landscape.  Surface mining (sometimes called quarrying or opencast mining) requires the removal of topsoil (the fertile layer of soil and organic matter that is particularly valuable for agriculture) to get at the valuable rocks below. Even if the destruction of topsoil is the worst that happens. Mining  Most metals, for example, occur in rocky mixtures called ores, from which the valuable elements have to be extracted by chemical, electrical, or other processes.  That leaves behind waste products and the chemicals used to process them, which historically were simply dumped back on the land.  Since all the waste was left in one place, the concentration of pollution often became dangerously high.  When mines were completely worked out, all that was left behind was contaminated land that couldn't be used for any other purpose.  Urbanization  One of the problems of urbanization is that, by concentrating people, it concentrates their waste products at the same time.  So, for example, crudely disposing of sewage from a big city automatically creates water or land pollution, where the same number of people and the same volume of sewage might not create a problem if it were created in 10 smaller cities or 100 small towns.  Concentration is always a key factor when we talk about pollution. Agricultural chemicals  The reality is that seven billion hungry people consume a vast amount of food.  Feeding the world on such a scale is only possible because agriculture now works in an industrial way, with giant machines such as tractors and combine harvesters doing the work that hundreds of people would have done in the past, and chemicals such as fertilizers and pesticides increasing the amount of food that can be grown on each piece of land. Agricultural chemicals  Unfortunately, most pesticides are by definition poisons, and many remain in the soil or accumulate there for years.  One infamous and now widely banned pesticide, DDT, is not ordinarily biodegradable so it has remained in the environment ever since it was first used in the mid-20th century.  DDT is just one of many organic (carbon-based) chemicals that remain in the environment for years or decades, known as persistent organic pollutants. Effects of land pollution  The simplest effect of land pollution is that it takes land out of circulation.  The more land we use up, the less we have remaining.  That might not sound a problem where there's plenty of land in rural areas, but it's certainly a concern where productive agricultural land is concerned, especially as the world's population continues to increase.  The biggest problem comes when contaminated land is returned to use. Effects of land pollution  However, we do know what effect individual pollutants have.  We know, for example, that lead is a toxic heavy metal that has all kinds of unpleasant effects on human health; it's been implicated in developmental deficits (such as reductions in intelligence) in children.  We know that some chemicals are carcinogenic (cancer- causing) while others cause congenital defects such as heart disease. 15  Solutions  What kind of solutions? Ideally, we'd look at every aspect of land pollution in turn and try to find a way of either stopping it or reducing it. With problems like waste disposal, solutions are relatively simple.  We know that recycling that can dramatically reduce the need for sending waste to landfills.  Ideally, we don't just need to stop polluting land: we also need to clean up the many contaminated sites that already exist.  Solutions  Many former nuclear sites have already been cleaned up as much as possible.  Where sites can't be completely restored, it's possible to "recycle" them and benefit the environment in other ways; for example, a number of contaminated sites and former mines in the United States have now become wind farms or sites for large areas of solar panels.  All these things offer hope for a better future—a future where we value the environment more, damage the land less—and realize, finally, that Earth itself is a limited and precious resource.