Trace elements world soils

Years ago, the author and Dr. Amos Banin from the Hebrew University of Jerusalem, Israel started to plan such a timely book to meet the current needs of the world s arid environments. Much research on biogeochemistry of trace elements in arid soils was done by the author and Dr. Banin during the period from 1992 to 1997 when the author was at the Hebrew University. Therefore, a majority of the chapters of this book were formed at that time. Of course, many materials and first-hand data are from the previous publications by the author and Dr. Banin s laboratory. Unfortunately, due to the health problems of Dr. Banin, he was unable to get this project finished. Thus this book is a product that resulted from the collaborative efforts and coauthoring between the author and Dr. Banin. 

The book focuses on the biogeochemistry of trace elements in arid and semiarid zone soils and includes an introductory chapter on the nature and properties of arid zone soils. It presents an updated overview and a comprehensive coverage of the major aspects of trace elements and heavy metals that are of most concern in the world s arid and semi-arid soils. These include the content and distribution of trace elements in arid soils, their solution chemistry, their solid-phase chemistry, selective sequential dissolution techniques for trace elements in arid soils, the bioavailability of trace elements, and the pollution and remediation of contaminated arid soils. A comprehensive and focused case study on transfer fluxes of trace elements in Israeli arid and semi-arid soils is presented. The book concludes with a discussion of a quantitative global perspective on anthropogenic interferences in the natural trace elements distributions. The elements discussed in this book include Cd, Cu, Cr, Ni, Pb, Zn, Hg, As, Se, Co, B, Mo and others. This book is an excellent reference for students and professionals in the environmental, ecological, agricultural and geological sciences. 

Table 2.1. Concentrations of trace elements in the earth s crust, rocks, and world soils ... 

Zinc is the 24th most abundant element in the earth s crust. The Zn concentration in the lithosphere is 50-70 mg/kg (Vinogradoc, 1959 Adriano, 2001). Basic igneous rocks contain higher Zn (70-130 mg/kg) than metamorphic and sedimentary rocks (80 mg/kg). Carbonate and limestones contain low Zn (16-20 mg/kg) (Aubert and Pinta, 1977). The total Zn concentration in the soils of the world ranges from 10 to 300 mg/kg (Swaine, 1955), with average concentrations from 50 to 100 mg/kg (Aubert and Pinta, 1977). Arid and semi-arid soils vary from trace levels (subdesert soils) to 900 mg/kg (saline alkali soils) (Aubert and Pinta, 1977). The average Zn concentration in the arid and semi-arid soils of the U.S. (62.9 mg/kg) is... 

Bioavailable trace elements in world arid and semi-arid soils vary widely, depending upon the nature of the parent materials, soil pH, CaC03 and clay content, and soil texture. The contents of bioavailable trace elements in arid and semi-arid soils of selected countries are presented in Table 7.6. The data are recalculated from Sillanpaa (1982) and cited from Liu (1996), Han and Banin (1997, 1999) and many others. 

Table 9.4. Trace element contents of the lithosphere and world soils (mg/kg) (Data from Han et al. 2002a, with kind permission of Springer Science and Business Media)...

Global extent of arid and semi-arid soils (km2) based on the Soil Taxonomy system) (after Monger et al., 2004). Concentrations of trace elements in the earth s crust, rocks and world soils3. 

A. Kawasaki, H. Oda, T. Hirata. Determination of rice provenance using strontium isotope ratio and levels of selected trace elements of rice, Trans. World Congr. Soil Sci., (2002), 2019/1-2019/9. 

Three-quarters of the metal minerals are processed and mostly consumed in the relatively small highly industrialized countries which contain one-quarter of the world s population. The aerial concentration of processing and consumption causes environmental problems, and the risk of contaminating soils, rivers and air with toxic trace elements is high in industrialized countries. Beside the firing of coal and oil, processing of ores and the technical use of several metals is a major source of such contamination. 

Tab. 5.5 Mean and maximum values (mg kg" ) of the background ranges reported for trace elements in different soil kinds on the world scale. Adopted from Kabata-Pendias and Pendias (2001) and Tobias et al. (1997)...

In the parent rock, only Co, Zn, V and particularly Cr and Ni are important trace elements (up to several thousand ppm for the latter two). The other trace elements are below the detection limit of most instruments (bottom of Fig. lOD, Appendix A.3). The soil profile described on Fig. lOD is only 10-cm-thick and lies on peridotites. The soil is acid (pH between 5.7 and 5.9), but the soil percolation and spring waters are alkaline (pH 1.6-1.9). This is a general tendency in soils developed on peridotitic rocks. In a comparable situation on serpentinites, but in a colder climate, Juchler (1988) describes percolation waters whose pH increased from 6.1 in the 0-horizon to 7.2 in the BC-horizon and 8.1 in local springs. Such alkaline waters, buffered by various hydrous Mg-carbonates are typical for ground waters from Mg-rich rocks all over the world (Pfeifer, 1977). 

Description. Iodine, a nonmetallic trace element, is required by humans for the synthesis of thyroid hormones, triiodothyronine (Tj) and thyroxine (T4). Iodine deficiency is an important health problem throughout much of the world. Most of the Earth s iodine is found in its oceans. In general, the older an exposed soil surface, the more likely the iodine has been leached away by erosion. Mountainous regions, such as the Himalayas, the Andes, and the Alps, and flooded river valleys, such as the Ganges, are among the most severely iodine-deficient areas in the world. ° ... 

In areas which have been subjected to intensive glaciation, such as Scotland, the soils are often derived from mixtures of different types of rock and the nature of the parent material may vary, even within farm fields. In such circumstances, prediction of soil trace-element content may be very difficult. A further complication is that the total content of any trace element in the soil normally gives little indication of the availability of that element to plants, and Mitchell and co-workers have published several papers dealing with the factors affecting availability [6,84,85]. On the other hand, there are extensive regions in the world, for example, in central Australia, in the mid-west of the USA and in the steppes in the Soviet Union, where the soil is almost uniformly derived over wide areas from the same kind of parent material and where neither the total nor the available levels of trace elements vary very much. 

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. 

The serious problem of arsenie pollution in soils and subsurfaee waters due to mineral dissolution, use of arsenical pesticides, disposal of fly ash, and mine drainage is well known all over the world. Even homogeneous phase speciation of arsenic species in aqueous solutions is very complicated, because this trace element exists in different redox and multistep aeid-base dissociation equilibrium states. A wide range of adsorbents and several methods, such as spectroscopic techniques (FTIR, Raman, X-ray absorption speetra [XAS] extended X-ray absorption fine structure [EXAFS]), elecfrophoresis, in addition to adsorption measurements were used to study the sorption of arsenite and arsenate. Several noteworthy applications of SCMs for evaluation of experimental results are known. One of them is an exeellent example for... 

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