Ground soil pollution, causes

TABLE 1 SOME CAUSES OF GROUND SOIL POLLUTION IN USA... 

Before about 1950, landfill effects were ignored. When attention was first directed to the problem 20 or 30 years ago it was thought that in most places landfills caused little damage. Today it is known most landfills have had a dreadfully effect on soil and water quality. Rain percolates down through the decaying layers and carries toxic materials into the water table. This can cause serious ground water pollution when the waste consists of only domestic trash. When industrial trash, with a broad spectrum of materials, is included along with the domestic waste the problem becomes worse. 

Figure 16.15 shows that four rods (electrodes) are drilled in the polluted area. An electric current is passed between the electrodes, melting the soil between them. Melting starts near the ground surface and moves downward. As the soil melts, the electrodes sink further into the ground, causing deeper soil to melt. When the power is turned off, the melted soil cools and vitrifies, which means it... 

Both settle-able and suspended atmospheric particles have deleterious effects upon the environment. The scttlc-able partidcs can affect health if assimilated and also can cause adverse effects on materials, crops, and vegetation. Further, such partides settle out in streams and upon land where soluble substances, sometimes including hazardous materials, are dissolved out of the particles and thus become pollutants of soils and surface and ground waters. Suspended atmospheric particulate matter has undesirable effects on visibility and, if continuous and of sufficient concentration, possible modifying effects on the climate. Importantly, it is particles within a size range from 2 to 5 micrometers and smaller that are considered most harmful to health because particles of this size tend to penetrate the body s defense mechanisms and reach most deeply into the lungs. 

Indirect Sources Air, water, and soil can become polluted from a variety of indirect sources. Motor vehicles and factory smokestacks release gases that can indirectly cause many different types of pollution. The acidic gases that are produced (sulfur dioxide and nitrogen oxides) dissolve and contribute to the formation of acid rain. The concentrations of ions in ground water are affected by how acidic the water is. 

Synthetic dyes are extensively used in many up-to-date industrial processes and research, mainly in the preparation of textile, food, and leather products, as well as in cosmetics and medicine. The widespread application of synthetic dyes has resulted in serious environmental pollution Their occurrence in ground water and waste-water and the accumulation in sediment, soil, and various biological tissues has often been observed and reported. Dyes and intermediates can cause abnormal reproductive function in males and show marked toxic effects toward bacteria. The rate of biodegradation of the majority of synthetic dyes is very low, enhancing the toxicological hazard and environmental impact. 

Nitrate is a naturally occurring compound that is formed in the soil when nitrogen and oxygen combine. Small amounts of nitrate are normal, but excess amounts can pollute supplies of ground and surface water. For most people, consuming small amounts of nitrate is not harmful. However, it can cause health problems... 

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