Rocks, Soils, and Water

Rocks and Soils Potassium is a major element of the lithosphere with an average level of 24.1-25.9 g kg (Falbe and Regitz 

though the potassium content in the main rocks varies greatly. In crystalline. 

Water Potassium concentrations in surface water vary from 0.98 mg L (Amazon) to 2.65 mg (Gonga). The reported world average is 1.48mgL k Potassium concentrations in ground water are commonly low, partly because of the high degree of stability of potassium-bearing alumina silicate minerals. Some of the potassium, however, is also removed from water by the conversion of clays, for example of montmorillonite into illite and chlorite. In these clays, potassium is incorporated into 

In the ocean, the concentration of potassium, though substantial (390 mg L ), is far lower than that of sodium (10500 mg L ). Sodium tends to remain in solution rather persistently once it has been liberated from a silicate mineral structure, whereas potassium is liberated with greater difficulty from silicate minerals and exhibits a stronger tendency to be reincorporated into solid weathering products, especially certain day minerals. Consequently, in most natural waters, the concentration of sodium generally exceeds that of potassium (Nativ 1992). 

The concentration of the essential macro element potassium in plants is varied by the amount of plant-available potassium in the soil, plant age, species, and plant parts. 

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Rocks, Soils, and Water The iodine content of most rocks varies, from 0.01-0.50 mg kg in ultramafic rocks (dunite, peridotites, pyroxenites) to 2-6 mg kg with the greatest amounts being found in shales that are rich in organic matter. Mafic rocks (basalt) store 0.08-0.50 mg I kg granite and gneisses 0.2-0.5 mg kg sandstones 0.5-... 

U-235 and U-238 occur naturally in nearly all rock, soil, and water. U-238 is the most abundant form in the environment. U-235 can be concentrated in a process called enrichment, making it suitable for use in nuclear reactors or weapons. 

Uranium is a naturally-occurring element found at low levels in virtually all rock, soil, and water. Significant concentrations of uranium occur in some substances such as phosphate rock deposits, and minerals such as uraninite in uranium-rich ores. Because uranium has such a long radioactive half-life (4.47x109 years for U-238), the total amount of it on earth stays almost the same. 

Radon is a radioactive gas formed by the natural decay of uranium in rock, soil, and water. 

Identification and quantification of mineral and chemical forms of arsenic in rocks, soils, and sediments that constitute the natural forms of arsenic entering water and the food chain... 

The increased solute-loading in terrestrial waters is due to dissolution of minerals in rock, soil and overburden materials as rainwater infiltrates them. Groundwater experiences the largest degree of water-rock interaction and consequently has the highest average... 

Iodine is essential in the mammalian diet to produce the thyroid hormone thyroxine deficiency in humans causes goitre. Collectively, deficiencies of iodine, iron, zinc and vitamin A in humans are thought to be at least as widespread and debilitating as calorie deficiencies (Welch and Graham, 1999). The main source of iodine in soils is oceanic salts rather than parent rock, and so deficiency is most widespread in areas remote from the sea (Fuge, 1996). In principle deficiency is easily corrected with dairy supplements. However in practice this is not always feasible. Addition of iodate to irrigation water has successfully corrected widespread iodine deficiency in parts of China where the usual methods of supplementation had failed (Cao et al., 1994 Jiang et al 1997). However there is not much information on the behaviour of iodine in soil and water systems. 

The fibrous forms of amphiboles, and serpentines, in addition to occurring in aggregates amenable to mining, are widespread as minor constiments of many rocks. The fibers are also widely distributed throughout the soils and waters of the world. These occurrences, together with the many long-term uses for asbestos society has devised, ensure that the ubiquitous presence of asbestos in our environment. 

The return of sulfates from the soil and water medium to the atmosphere is connected with rock weathering and spray above a rough water surface Cn = d2 RATE S04L, Hu = 0 RATE S04U, where RATE(ip, A, t) is the wind speed over the surface, m/s, and d2 and 0 are empirical coefficients. 

The water-rock/soil and organic matter-minerals (including soil organic matter-clay), interactions can also be studied by infrared spectroscopy (Chapter 2, Section 2.1.2). 

The ratio of to would be expected to be unity as long as the uranium stays locked inside undisturbed crustal rock in secular equilibrium with its progeny, but measurements show that the ratio is typically different than unity (EPA 1994). This disequilibrium occurs when the rock is disturbed by chemical or physical changes involving water. In the environment, a portion of the separates from the by what is theorized to be a physical process (alpha recoil ejection of the Th decay product from surfaces of soil particles) or a combination of physical and chemical processes (a transformation at the soil particle surface fractures the surface allowing access for water to dissolve the more soluble Th product) (NCRP 1984a). These processes can change the uranium isotope ratios in air, soil, and water. 

Medical geochemistry (also referred to as environmental geochemistry and health Smith and Huyck (1999), Appleton et al. (1996)) can be considered as a diverse subdiscipline of medical geology that deals with human and animal health in the context of the Earth s geochemical cycle (Figure 1). Many medical geochemistry studies have focused on how chemical elements in rocks, soils, and sediments are transmitted via water or... 

Some types of nickel or silver ore deposits. Soils and waters affected by smelter emissions, mining wastes and by-products. Some rocks such as black shales, ultramaflc rocks. 

Soils and waters affected by emissions from smelters, power plants. Soils and waters affected by mining wastes and by-products. Some playa lake sediments. Soils and dusts derived from naturally As-enriched rocks and sediments. Waters that have leached As from As-rich rocks, soils, and sediments. Pesticides, other industrial chemicals. By-products or wastes from chemical manufacturing or other industrial processes. 

Enriched in relatively insoluble form in silicates in pegmatites also enriched in some coals and alkalic rocks and their associated mineral deposits. Soils and waters affected by emissions from coal-fired power plants. 

A variety of rocks, soils, sediments, dusts. Tores, and other solids are enriched in uranium (U) and thorium, which can decay to radon, radium, and other daughter products. Ground waters that have traveled through U-rich rocks, soils, and sediments. 

With very few exceptions, surface and near surface waters contain an excess of Rn (Table I l-III) compared to Ra (Table 11-lV) and U (Table 11-VI). This Rn must come from Ra in solids such as rocks, soils and sediments. The solubility product of Ra salts is seldom reached in natural waters, because invariably it is adsorbed onto sulphates and carbonates at the surfaces of rocks and minerals. In the zone of oxidation it is also coprecipitated by hydrous oxides of Fe and Mn. Only in the vicinity of strong sources of very saline waters do Ra concentrations rise to 10 or even 10 g/L. 

Escape of radon and its daughters from soils into the atmosphere is highly dependent on meteorological conditions and the types of soils in the particular area. Release from rock, soils, and other materials is not well understood. Radon and its daughters are readily adsorbed on various surfaces and surface waters are known to contain some amount of radon. In the atmosphere, one part of radon is thought to be present in 1 x 10 parts of air but these concentrations vary daily and seasonally. 

Concentration (C ) in flow from any areal section is a function of input from source rocks and soils, and water discharge ... 

Because of this, it is highly important to understand the environmental behavior of Pu and Am. This symposium was organized in order to ascertain the current state of our knowledge about the behavior of these isotopes in rocks, soils, ground water, and biosystems. 

The rubidium content of water is subjected to the same rules as rubidium transfer from rocks to the soil and from soils into plants. On average, water from granite, gneiss and phyllite contains 14-18 pgL while that from Pleistocene and Holocene formations (diluvial sands) and Muschelkalk proved to be particularly poor in rubidium (3.1-3.5 pgL Y The rubidium contents in different soils and waters are mainly determined by the rubidium concentrations in the source material for soil formation. Anthropogenic influences on the rubidium content in the soil and water are hardly probable (Anke and Angelow 1995). 

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