Soils, Sediments and Dust

Soils in Agricultural Zones. Natural lead concentrations in soils are in the range 2-20 mg/kg with averages near 16 mg/kg, although variations can be considerable (Tsuchiya 1978). 

particularly from the use of leaded gas in vehicles, is often the more important metal of anthropogenic origin deposited in soils. It is usually retained as coordination complexes because in general, these are not soluble, the transfer of lead from soil to plants is relatively difficult, although in some cases it might be of importance. In Mexico, despite the multiple sources of lead and its importance, the presence of lead in soils has not been adequately studied, as is evident from the following sparse data. 

If the extension of the country is considered, as well as the importance and the number of the sources that might contribute to the levels of lead in soils, it will be evident that the studies described above are altogether insufficient to reach even a preliminary conclusion with regard to the state of lead pollution in soils in the agricultural and other regions of Mexico. 

Soils in Urban Zones. In an unpublished study carried out in 1979, Gonzalez and Esquivel (1979) determined the lead concentrations in soil samples obtained near some of the avenues with the heaviest traffic density in Mexico City (see Table 12). From their results, they concluded that soils near avenues to the south of Mexico City had the lowest concentrations of this element and those from the north-northwest of the city, the highest. The same authors carried out a simultaneous study on the lead concentrations in vegetation growing nearby these avenues. These data will be presented later in this review. The authors did not specify their methodology or the analytical controls they used. 

As can be seen, the levels reported were not very high, especially when the data on leaded gas consumption in the MZMC and those of lead levels in air and fallout in the city are considered. Because no other study of this type is available, either for Mexico City or for any other city in the country, these results should be considered only as indicative and are included here mainly to stress the need for more data on lead in urban soils, particularly in cities such as Torreon, Chihuahua, and Monterrey, where smelting, refining, and lead-related industries occur. 

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Besides the organic pollutants mentioned above, e-waste recycling activities are also releasing various heavy metals such as Hg, Cd, Cr, Cu, Ni, Pb, and Zn [14]. These e-waste-derived heavy metals pose extremely high risk to the environment and humans [67], especially at e-waste processing sites. Numerous previous studies suggested that most environmental matrices around e-waste sites, such as air, soil, sediment, and dust, have been severely contaminated by these heavy metals (Table 2) [71-75],... 

Soil, sediment, and dust samples were prepared in a similar way before analysis. After the pre-cleanup steps and homogenization, FRs were extracted from samples using different solid-liquid extraction techniques. The most commonly used technique was accelerated solvent extraction (ASE), which enables the fast extraction of samples using different solvents such as hexane and dichloromethane [98-100]. Other commonly used techniques for these samples were ultrawave-assisted extraction (UAE) [97], which also enabled quick extraction, and the more time-consuming but very efficient technique, Soxhlet extraction [96]. Some authors have also described less common techniques such as microSPE [95]. There is also information that many FRs that are no longer produced (mainly PCBs and PBDEs) are present in dusts, soils, and sediments in very high amounts, even 390 pg/g [98]. 

Labunska, I. Levels and distribution of polybrominated diphenyl ethers in soil, sediment and dust samples collected from various electronic waste recycling sites within Guiyu town, southern Qiina. Environ. Sci. 15, 503 (2013)... 

If di-n-octylphthalate is released into die air, it may be deposited on the ground or to surface water in rain or dust particles. Di-n-octylphthalate sticks tightly to soil, sediment, and dust particles. Small amounts of di-n-octylphthalate can build up in animals that live in water, such as fish and oysters. 

BIOLOGICAL PROPERTIES attaches to soil, sediments, and dust particles in the air can move into the groundwater and into lakes, streams, and rivers most of the zinc in soil stays bound to soil particles... 

Interfacial transfer is the transport of a chemical across an interface. The most studied form of interfacial transfer is absorption and volatilization, or condensation and evaporation, which is the transport of a chemical across the air-water interface. Another form of interfacial transfer would be adsorption and desorption, generally from water or air to the surface of a particle of soil, sediment, or dust. Illustration of both of these forms of interfacial transfer will be given in Section l.D. 

The observed metal phosphate phases agree with thermodynamic models of the ash system described here. These phases control leaching in pH-stat systems and are present after aggressive leaching designed to remove available or leachable fractions. These phases are also similar to ones observed in soil, sediment, smelter dust, industrial wastewater, and slag systems. 

Environmental RM (e.g., waters, sediments, bioindicators, soils, ashes and dusts)... 

The simplest first-generation predictive Pb exposure models consisted of statistical or ad hoc, mathematical models. These came into wide use in the 1960s and 1970s with the development of reliable measurement methods for blood lead levels and for Pb in diverse environmental media air, dust, diet, soil, sediment, and water. The models employed regression analyses of the relationship of lead in diverse environmental media to lead in blood of children or adults. 

HBCD accumulates in soil, sediments and airborne dust, and is rapidly absorbed in the gastrointestinal tract and accumulates in the fatty tissue of organisms, but has a very short hah-life. For example, in fish the half-life of HBCD is only one day. Representation of the individual isomers in the sediments reflects the compositions of commercial mixtures, while the tissues of aquatic animals, especially fish, have a quite different composition of isomers. The dominant substance is the a-isomer the y-isomer is present in much smaller amounts and the content of the fl-isomer remains virtually constant, which can be explained by the almost selective biotransformation of the y-isomer to the a-isomer. 

Environmental and agricultural studies involve a number of different materials that need to be analysed. The principal test materials encountered by the analyst in this sector are soils, sediments, air, dusts, water, plant material and animal tissue. For completely practical reasons, we need to know the composition of these media over wide concentration ranges, from major constituents to elements at ultratrace levels. One is especially interested in the way elements are transferred between media, their biological role and metabolic pathways, and their ultimate fate. 

Quantitative estimates of microbial and community structure by means of analysis of the phospholipid fraction have been performed on. sediments, water (135), and dust (136) as well as. soil (137-141). The method is applicable to the study of mixed populations of varying degrees of complexity and is relatively straightforward to perform. A selection of studies involving the analysis of fatty acid profiles of environmental samples are outlined in Table 6. 

All soils contain soluble salts, but their concentration is low. The salt content of most arid soils is, however, much higher. Salts in desert soils are usually derived from three main sources (1) deposition of wind-blown salt spray or dust (2) in situ weathering of salt-containing rocks or sediments, and (3) upward movement with the capillary flow from a shallow salty groundwater. Along the coastline, some salinization may occur through intrusion and flooding by seawater. 

Fig. 9. GC-MS TIC traces for silylated total extracts of soil, river sediment and aerosol samples (a) Amazon Forest soil (Manaus, Brazil) (b) almond orchard agricultural field soil (CA, USA) (c) Harney River sediment in Everglades National Park (FL, USA), and (d) Gosan Island (Korea) aerosol during Asian dust event (April 27—28, 2001). Numbers refer to carbon chain length of homologous series ( = rj-alkane, o = rj-alkanol, A = rj-alkanoic acid, DHA = dehydroabietic acid, ik = isoprenoid ketone, S = sitosterol). 

Some very fine-grained atmospheric dust is capable of crossing oceans and accumulating on different continents. Dust samples from the Sahara Desert of North Africa (Mali) are known to contain at least 17 mg kg-1 of arsenic and may be responsible for contaminating cisterns as far west as the Caribbean and eastern USA ((Holmes and Miller, 2002 Shinn, 2001) Table 3.17). Dust in one cistern from St. John, US Virgin Islands, contained about 38 mg kg-1 of arsenic ((Holmes and Miller, 2002) Table 3.17). Arsenic from Sahara Desert dust may also accumulate in soils, sediments, water, and plants in Florida and surrounding areas (Holmes and Miller, 2002). 

This area has most recently been reviewed by Covaci et al. (2007a). Matrices commonly analysed include air, dust, soils, sediments, sewage sludges and a wide variety of biota samples, both terrestrial and aquatic (Law et al, 2008b). BFRs have not been widely determined in water as these compounds are hydrophobic with high log values, and will... 

Another example of ultrasound use is leaching of organic impurities from different kinds of samples. The main analytes of interest are PAHs, which are widespread in soil, sediment, dust, and particulate samples [55]. USE is recommended as a fast, efficient, and direct environmental sample preparation method for determination of PCBs, nitrophenols, pesticides, or polymer additives. Organometallic and biologically active compounds (such as vitamins A, D, and E) present in samples in trace quantities, can be extracted from animal and plant tissues with the aid of ultrasonic wave energy [59]. Table 6.6 presents some typical applications of USE in trace analysis of biological and environmental samples [60]. 

Therefore, FRs are determined in different matrices, both environmental and biological. The existing literature mainly focuses on the determination of compounds that have been available for many years, or even long after their production was banned (e.g., PCBs). The desirability of such research is justified by the fact that many of these compounds are still present in real samples as a result of their high durability and release to the environment from products produced before the introduction of prohibitions (and still present on the market). That is why it is important that, along with development of new FRs, analytical procedures are provided for their determination in various matrices, especially those with which we are in most frequent contact. The literature describes FR determination mostly in samples of surface water [93,94], soils [95,96], sediments [97,98], and dust [99, 100]. These environmental matrices are in often contact with materials that contain FRs. Moreover, from these matrices it is very simple for FRs to come into contact with animals and humans ttherefore, it is very important to monitor the concentrations of FRs in those matrices. 

This chapter describes analytical procedures of the highest potential for analysis of biological (physiological fluids and tissues) and environmental (plants, airborne particulates and dusts, soils and sediments) samples for Pt and Ru used in chemotherapy and for Pt, Pd, and Rh used as components of autocatalysts. 

The problems of the presence of PGMs in various environmental compartments and human exposure to them have been discussed in numerous review articles and books. [2-8, 10-13, 189]. We describe analytical approaches to the evaluation of the content of Pt, Pd, and Rh in plants, airborne particles and dusts, and soils and sediments, which are the most often examined materials for such purposes. 

Evaluation of the content of PGMs in airborne particles and dusts is important because of the possibility of their inhalation and accumulation in human lungs. Nanoparticles from autocatalysts can be transported into various parts of the environment (waters, plants, soils, and sediments) and transformed into more bioavailable species. There are data on the higher solubility of platinum from tunnel dusts than from inorganic species emitted from converters [30]. Distribution and accumulation of metals depend on traffic density, distance from the road, and meteorological conditions (wind, rain). The age of an autocatalyst and speed conditions directly affect the amount of nanoparticles released from catalytic... 

In addition to the effects on climate and soils, mentioned above, study of deep-sea sediments and ice cores indicate that, during glacial periods, dust deposition rates were 2-20 times the current values (Thompson and Mosley-Thompson, 1981 Hammer ef fll., 1985 Petit efal., 1990 Rea, 1994 Steffenson, 1997 Reader et al., 1999), possibly because of the effect airborne minerals had on global climate by their interactions with solar and terrestrial radiation (Andreae, 1995, 1996 Duce, 1995 Li et al., 1996 Sokolik and Toon, 1996 Tegen and Lads, 1996 Mahowald et al., 1999). Possible relations between glacial periods and dust have been the subject of intense speculation. 

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