Contamination of the Soil

As a manufactured element, americium is not naturally present in rocks and soils. Contamination of the soil can occur either from deposition of americium or precursor plutonium originally discharged into the atmosphere, or from waste products discharged directly into or on the ground. Except for the reentry into... 

Adamo, P., Arienzo, M., Bianco, M. R., and Violante, P. (2002a). Heavy metal contamination of the soils devoted to stocking raw materials in the former ILVA iron-steel industrial plant of Bagnoli (south Italy). Set. Total Environ. 295, 17-34. 

Toxoplasmosis is a recurrent, potentially blinding, disease caused by the obligate intracellular parasite Toxoplasma gondii. Toxoplasmosis affects millions of people worldwide. Cats are the definitive host for the parasite but not the primary source of human infection. Environmental contamination of the soil, water, fruits and vegetables, and infection in other animals cause most human infections. Human infection may be either congenital or acquired, and acquired disease appears to be the most prevalent. 

The landfilling of paint containers with leftover contents is another environmental issue. In most jurisdictions these are not accepted in landfill sites because of their potential for contamination of the soil, so waste paint is normally collected at a special depot, along with other household hazardous waste. The paint industry has developed techniques for collecting paint from these waste depots, testing for contamination, and reformulating the paint into a usable product. 

Large drops, with their greater kinetic energy, can cause problems as they impact on crops. Drops greater than 200 im diameter (Brunskill, 1956) have the potential to cause spray runoff and contamination of the soil. With the lowering of spray volume rates, and the use of more fine nozzles, this problem has reduced in importance in recent years, but the trend towards the use of coarse sprays for drift reduction may reintroduce the problem in the near future. 

However, considering the obvious and at some places extreme arsenic contamination of the soil, the arsenic content of the plants appears to be surprisingly moderate. As a result of this study the authors concluded that a dangerous contamination of the nutrition chain by arsenic via plant uptake was not observed. 

Suitable methods for speciation analysis of phenylarsenic compounds in soil and plant samples have been developed. In spite of the considerable contamination of the soil, the arsenic content of terrestrial plants is apparently modest. 

The use of an Impermeable flexible membrane liner will allow salt gradient solar ponds to be located near the energy user, by preventing salt contamination of the soil and ground water. 

Former industrial areas can be extremely difficult to reclaim for residential or public use because of long-lasting contamination of the soil. These contaminated soils can subsequently become sources of air and water pollution. One particularly recalcitrant group of contaminants are the PAHs, which frequently become soil contaminants after spills or leaks from oil and gas storage tanks. What nanomaterial could be used for remediation of spilled PAH, and how much removal could be expected after 1 h if 0.15 g material/g soil were used ... 

Figure 5.7. Floodlands of the river Techa (Ural region) contaminated by the radionuclides as a result of emergency on the manufacturing association Mayak. The zone of the radioactive contamination of the soil on Cs composes l-5Ci/km, and on Sr composes 0.15-3.0Ci/km (Federal Forestry Agency of the Russian Federation, 2007).

These materials are also used extensively as membranes in acid-brick-lined vessels to protect the steel shell from corrosive attack. The add-brick lining, in turn, protects the elastomer from abrasion and excessive temperature. Another major use is as an impermeable lining for settling ponds and basins. These materials are employed to prevent pond contaminants from seeping into the soil and causing pollution of groundwater and contamination of the soil. 

Significant reduction in species composition, frequency and herbage production in several native plants due to the contamination of the soil with petroleum hydrocarbons [2, 14, 39]. 

We have computed the problem (UVC) for t G (0,180) minutes.The initial contamination of the soil was given by the Figure 4.1. The typical breakthrough surfaces of bacteria (mobile and sorbed) are shown at Figures 4.5, 4.6, respectively. At Figure 4.3 we can observe a peak in contaminant concentration which is very poisonous. Because it is confined to a very small area, there isn t any visible dip in the bacteria concentration at the same time, see figures 4.5 and 4.6. It will vanish later (Figure 4.4) due to the supply of bacteria. The influence of the adsorption capacity M and the adsorption rate... 

Contamination of the soil by fibrous minerals (anthophyllite, tremohte, sepiolite) is widespread, and evidence of pleural plaqueing in agricultural workers has been found in Turkey (Baris etal. 1978, 1979), Greece (Bazas etal. 1981), Bulgaria (ZOLOV et al. 1967, Burilkov 1968, Burilkov and Babadjov 1970, Burilkov and Michailova 1972), Yugoslavia, Czechoslovakia, and Austria. 

Another major use is as an impermeable liner for settling ponds or basins. These materials are employed to prevent pond contaminents from seeping into the soil and causing pollution of groundwater and contamination of the soil. 

TCDD contamination has resulted from improper waste disposal, the most notable case of which resulted from the spraying of waste oil mixed with TCDD on roads and horse arenas in Missouri in the early 1970s. Contamination of the soil in Times Beach, Missouri, resulted in the whole town being bought out and its topsoil dug up and incinerated at a cost exceeding 100 million. 

It has to be pointed out here that, in view of the varied nature of man s diet and the impossibility of tracing the food consumed in any area of the Western World to its soil source, it has become extremely difficult to establish any epidemiological connection between the incidence of any disease and the trace-element composition of uncontaminated local soil. The fact that trace-element contamination of the soil is now universal in urban areas renders such studies highly speculative, except in rural areas where most of the food consumed is locally produced. 

If we take a broad view of what is happening to the trace-element composition of the soil environment, we can see that there are two main trends affecting the rural and urban environments in very different ways. In the rural areas, the general trend is slow depletion of the essential trace-element reserves in the soil, while in urban and industrial areas, it is quite rapid contamination of the soil with both essential and non-essential trace elements. The original trace-element levels in the soil resulting from natural processes, are now only found in rural areas, and even such areas are far from free from elemental... 

Trace-element contamination of the soil is general in urban areas of every size, but in the vicinity of industrial concentrations, the levels of contamination may be exceptionally high. We appear to be in the process of producing new soil environments with metal contents quite unlike anything occurring in natural conditions. The sources of this contamination and its possible consequences are discussed in the following chapters. 

In rural areas, not only is the effect of fallout of trace elements from atmospheric pollution dramatically less, but there are relatively fewer sources of incidental contamination of the soil with particular elements. The practice of spraying the haulms of seed potatoes with solutions of arsenious oxide, in order to arrest further growth of tubers, has now, happily, been discontinued. Although this practice was widespread a few years ago, it was never justified, because dilute solutions of sulfuric acid are perfectly adequate for the purpose. 

The levels of trace elements found in the majority of sludges are so high that their use as fertiliser must inevitably lead to contamination of the soil One cannot, therefore, generalise about the suitability of sludge as a fertiliser, since each batch produced must be judged on the basis of its trace-element composition, and this may vary widely even from a single disposal plant. 

The addition of even moderate dressings of municipal compost to rural soils (say, 25 tonnes per ha) can therefore be expected to have a pronounced effect on their trace-element content. What evidence we have suggests that, with the exception of boron, once these elements are introduced into the soil, they are not readily leached out again. Since contamination of the soil with trace elements will lead to increased uptakes by plant roots, with the possibility of ill-effects on the plants or on the animals eating them, it is important to consider the consequences of the agricultural use of this material. 

While the main source of contamination of the soil with trace elements is waste disposal of one kind or another, the use of inorganic compounds of highly toxic elements as pesticides, and the development of organic pesticides containing such elements, has created new problems of environmental pollution which require separate consideration. The term, pesticide, covers the insecticides, fungicides and herbicides widely used in agriculture and it can also... 

Before one can assess the possible consequences of trace-element contamination of the soil producing known available levels as determined by soil analysis, it is necessary to have reliable data on the relationship between available levels for the elements involved and plant uptake. A knowledge of the normal ranges of available levels found in soil and normal ranges of levels... 

The ability of plants to restrict their uptake of copper, lead and mercury from contaminated soil is also limited and, since contamination of the soil with most trace elements appears to be cumulative and largely irreversible, a point will eventually be reached when contaminant levels of these elements will render land permanently unsuitable for grazing or for growth of crops. 

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