Soil, chemical analysis pollutants

Finally, toxicity (defined in terms of a standard extraction procedure followed by chemical analysis for specific substances) is a characteristic of all chemicals, whether petroleum or nonpetroleum in origin. Toxic wastes are harmful or fatal when ingested or absorbed, and when such wastes are disposed of on land, the chemicals may drain (leach) from the waste and pollute groundwater. Leaching of such chemicals from contaminated soil may be particularly evident when the area is exposed to acid rain. The acidic nature of the water may impart mobility to the waste by changing the chemical character of the waste or the character of the minerals to which the waste species are adsorbed. 

Chemical elements that are either present naturally in the soil or introduced by pollution are more usefully estimated in terms of availability of the element, because this property can be related to mobility and uptake by plants. A good estimation of availability can be achieved by measuring the concentration of the element in soil pore water. Recent achievements in analytical techniques allowed to expand the range of interest to trace elements, which play a crucial role both in contaminated and uncontaminated soils and include those defined as potentially toxic elements (PTE) in environmental studies. A complete chemical analysis of soil pore water represents a powerful diagnostic tool for the interpretation of many soil chemical phenomena relating to soil fertility, mineralogy and environmental fate. This chapter describes some of the current methodologies... 

Environmental analysis Polluted areas, rivers, and soils can be effectively screened for hazardous chemicals with microarrays. In this approach, chemical species are incubated with specific labeled antibodies. Afterwards, the solution of marked toxins is exposed to microarrays containing an addressable structure of catcher molecules. 

Manufacturing industries rely on both qualitative and quantitative chemical analysis to ensure that all stages in the process meet the specifications for that product and supports cost-saving beneficiaries. The development of new products that are usually mixtures of reacted and unreacted raw materials may also require the analytical chemist to ensure that the product(s) formulations are correct and meet the customer s standards. Many industrial processes give rise to pollutants that can present health problems and, with the support of analytical chemistry, as much chemical information as possible is made known about the pollutants. Analysis of air, water, and soil samples as a result of industrial pollutants must be monitored to establish safe limits after removal and/or disposal. 

Ecotoxicity can only be measured by the application of biological methods, whereas chemical analysis determines concentrations of defined chemicals that may be used to deduce toxic effects. All concentration levels such as screening values, guideline values, threshold concentrations, benchmark concentrations and trigger values used for the assessment of contaminated media (water, soil, sediments, etc.) should ideally be derived from the observation of biological effects. Comparing pollutant concentrations with these usually conservative standard values is a common practice in the preliminary assessment of contaminated sites. The integration of further information, such as ecotoxicity data from the site, can improve the risk assessment process and enable a more reliable prediction of environmental threats. 

Characterisation of exposure. This process intends to estimate how much of a harmful chemical substance is for how long in contact with a specified organism. Exposure characterisation is usually a complex process that should consider physico-chemical properties of pollutants and the site (e.g. to estimate influencing factors such as the availability of contaminants), as well as naturally occurring pollutant degradation. For contaminated soils, exposure is usually estimated with measurement of toxicant concentrations by chemical analysis... 

The application of bioassays provides information that may not be obtained by chemical analysis. Biological tests are not intended to replace conventional soil analysis they should rather complement each other in assisting the assessment of soil pollution. Bioassays provide a direct measure of the effects of actual exposure. There is no need to extrapolate from measured chemical concentrations to possible effects. The prediction of bioavailability and combined toxicity from chemical concentrations always results in increased uncertainty. Bioassays consider soil-pollutant and pollutant-pollutant interactions by providing an overall toxicity response. They have the potential to detect (but not identify) the presence of toxic compounds that have not been considered in pollutant priority lists so far (e.g. non-target contaminants in pollutant groups like PAH that are hazardous to ecological receptors). 

Soil analysis is usually aimed at evaluating its agricultural characteristics. The soil chemical composition is very diverse and the definition of pollutants in soil, natural as well as anthropogenic, depends on the soil type, locality and also on the composition assumed to be normal . The comparison with assumed normal levels of particular components is achieved by using standard samples of soils, or of similar soils from a different region. Standard soil samples are not commonly available and thus, the second... 

Chemical analysis of hazardous substances in air, water, soil, sediment, or solid waste can best be performed by instrumental techniques involving gas chromatography (GC), high-performance liquid chromatography (HPLC), GC/mass spectrometry (MS), Fourier transform infrared spectroscopy (FTIR), and atomic absorption spectrophotometry (AA) (for the metals). GC techniques using a flame ionization detector (FID) or electron-capture detector (BCD) are widely used. Other detectors can be used for specific analyses. However, for unknown substances, identification by GC is extremely difficult. The number of pollutants listed by the U.S. Environmental Protection Agency (EPA) are only in the hundreds — in comparison with the thousands of harmful... 

Water, wastewater, and soil and air pollution analyses are the most important part of environmental analysis. Determination of common inorganic anions and cations is mandatory. Ion chromatography has almost replaced most of the wet chemical methods used in water analysis. This entry is a review of application of ion chromatography to environmental research. 

Analytical chemistry is important in practically all areas of human endeavor and in all spheres of the environment. Industrial raw materials and products processed in the anthrosphere are assayed by chemical analysis, and analytical monitoring is employed to monitor and control industrial processes. Hardness, alkalinity, and trace-level pollutants (see Chapters 3-5) are measured in water by chemical analysis. Nitrogen oxides, sulfur oxides, oxidants, and organic pollutants (see Chapters 6-8) are determined in air by chemical analysis. In the geosphere (see Chapters 9-11), fertilizer constituents in soil and commercially valuable minerals in ores are measured by chemical analysis. In the biosphere, xenobiotic materials and their metabolites (see Chapters 2 and 12) are monitored by chemical analysis. As discussed further in this chapter, analytical chemistry is very important in the area of occupational health and the practice of industrial hygiene. 

Models of chemical reactions of trace pollutants in groundwater must be based on experimental analysis of the kinetics of possible pollutant interactions with earth materials, much the same as smog chamber studies considered atmospheric photochemistry. Fundamental research could determine the surface chemistry of soil components and processes such as adsorption and desorption, pore diffusion, and biodegradation of contaminants. Hydrodynamic pollutant transport models should be upgraded to take into account chemical reactions at surfaces. 

Jin Q., Wang Z., Shan X., Tu Q., Wen B., Chen B. Evaluation of plant availability of soil trace metals by chemical fractionation and multiple regression analysis. Environ Pollut 1996 91 309-315. 

Atomic absorption spectrometry is one of the most widely used techniques for the determination of metals at trace levels in solution. Its popularity as compared with that of flame emission is due to its relative freedom from interferences by inter-element effects and its relative insensitivity to variations in flame temperature. Only for the routine determination of alkali and alkaline earth metals, is flame photometry usually preferred. Over sixty elements can be determined in almost any matrix by atomic absorption. Examples include heavy metals in body fluids, polluted waters, foodstuffs, soft drinks and beer, the analysis of metallurgical and geochemical samples and the determination of many metals in soils, crude oils, petroleum products and plastics. Detection limits generally lie in the range 100-0.1 ppb (Table 8.4) but these can be improved by chemical pre-concentration procedures involving solvent extraction or ion exchange. 

Meanwhile, these chemicals—like chemical agents encountered at work or in hobbies or as pollutants in air, water, soil, or food—can also cause harm. Sometimes the known mechanisms of action permit us to predict the nature of toxicity to be expected. A meta-analysis of prospective studies from U.S. hospitals indicates that 6.7% of in-patients have serious adverse drug reactions 0.3% have fatal reactions (Lazarou et al., 1998). In fact, estimates of 40,000 to 100,000 deaths per year attributed to errors in medical care, primarily due to adverse reactions to pharmaceuticals, make this phenomenon a major cause of death in the United States (Meyer, 2000). A tremendous... 

A broader and more detailed evaluation can be done by performing a Life Cycle Analysis (LCA). The central idea of a LCA is that the environmental effects during the entire life cycle of a process are quantified. These environmental effects are caused by the use of fossil fuels for heating and production of electricity, the use of non-renewable raw materials for the production of materials and chemicals, and the emissions of pollutants to air, water and soil. These environmental effects can be subdivided further in various levels of detail. The five major effects mentioned are derived from the more general effects considered in the framework of the LCA. Based on the environmental sustainability of each of the complete treatment scenarios considered as technically feasible, a ranking according environmental... 

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