Soil studies, forensic

Soil for microbiological studies is normally collected from the plow depth (10-23 cm at Rothamsted, United Kingdom, but it may vary elsewhere) and 0-10 cm depth for grassland or forest soils. For forensic analysis the sample depth will be decided by the nature of the crime scene. However, maximum biological activity will be adjacent to a corpse and will decline with depth... 

Analytical pyrolysis has been used successfiilly in many disciplines such as polymer chemistry, organic geochemistry, soil chemistry, forensic sciences, food science, environmental studies, microbiology, and extraterrestrial studies involving meteorites and lunar samples. A large number of organic substances found in nature are unsuitable for direct analysis by modern techniques such as column chromatography and mass spectrometry. This may be due to their complex structure and polar and nonvolatile character. 

The use of DRIFTS for the characterization of surfaces has to date been limited, but has recently been used for applications in fields as diverse as sensors development [12], soils science [13], forensic chemistry [14], corrosion [15], wood science [16] and art [F7]. Given that there is in general no reason for preferring transmission over difilise reflectance in the study of high-area powder systems, DRIFTS is likely to become much more popular in the near fiiture. 

Turner, B. D. and Wiltshire, P. E. J. (1999). Experimental validation of forensic evidence A study of the decomposition of buried pigs in a heavy clay soil. Forensic Sci. Int. 101,113-122. 

The use of the soil succession in PMI estimation will require development of successional databases for locations where it is to be applied. This will involve consideration of all invertebrate groups associated with carrion and selection of groups that are truly predictable in their arrival at a corpse in relation to decompositional stage. Numerous studies have identified groups both beneath the body and associated with burials that may be useful in PMI estimation, but the successional data required to apply such observations are still lacking. Invertebrates play an important role in terrestrial decomposition, and further study will provide a new method for estimation of PMI and open new frontiers in forensic entomology. 

Elemental results from soil forensic studies have been presented as spider diagrams (Pye and Blott 2004a) or as bivariate plots (Figure 11.4). Important considerations in using this type of information are how the values in the suspect sample may reflect a different fraction of the whole and, indeed, how the sample compares to every other sample. In addition, uncertainty increases as concentrations approach the limit of detection. A study of three soils using small sample sizes (0.05 g) showed that between sample variability... 

Nakayama, M., Fujita, Y., Kanbara, K., Nakayama, N., Mitsuo, N., Matsumoto, H., et al. (1992). Forensic chemical study on soil 1 Discrimination of area by pyrolysis products of soil. Jpn. J. Toxicol. Environ. Health 38, 38-44. 

Rawlins, B. G. and Cave, M. (2004). Investigating multi-element soil geochemical signatures and their potential for use in forensic studies, in Forensic Geoscience Principles, Techniques and Applications (K. Pye and D. J. Croft, Eds.). London Geological Society Special Publication 232,197-206. 

The terrestrial environment has been much studied as a decomposition environment for materials of little forensic value, such as leaf litter or dead roots. These provide the basic methods and framework for studying and understanding decomposition of materials in soils. It is only in recent years that this has been applied to forensic taphonomy, in which studies have been conducted with mammalian tissues and cadavers. The burial environment is a complex and dynamic system of interdependent chemical, physical, and biological processes. These processes influence, and are influenced by, the inclusion of a body and its subsequent decay. Though this book deals with what is known in this context, much still remains to be discovered, understood, and applied to forensic science. 

In the very first Sherlock Holmes story (A Study in Scarlet, first published in Beeton s Christmas Annual, 1887), emphasis is placed upon Holmes ability to tell different soil types at a glance , and this important ability features in a number of stories. Of course, Holmes had to make do with optical means to characterise the differing soils. The routine use of powder X-ray diffraction to quantify different soil types has made this an vastly more powerful tool, which is widely in use today, both geologically and in forensic science. 

FAO and IAEA, Stable Isotopes in Plant Nutrition, Soil Fertility, and Environmental Studies, IAEA, Vienna, 1991. J. Aniwasko, I. Kopp, A. Abrink and T. SkiOld, J. Forensic Sci. 38 (1993) 1161. 

The XRF method is nondestructive, an important feature when the sample is available in limited amounts or when it is valuable or even irreplaceable, as in the case with works of art, antiques, rocks from the moon, or forensic samples. The nondestructive nature of XRF coupled with the fact that sample preparation may not be required means that direct multielement analysis can be performed in situ. Portable HH XRF analyzers are used in the field by geologists to study soil and minerals, to sort metal scrap, glass, and plastics at recycling centers, for quality control in steel plants, and to check incoming lots of material before unloading a ship or a truck (Figure 8.54). 

Fibers and garments recovered as evidence may have been exposed to sunlight or water or buried for extended periods of time. Despite the significance of textile fibers as trace evidence, there have been few studies of the effects of the environment in which fibers are found on the procedures used to identify and compare them. It was the object of this study to expose various synthetic fibers to a soil environment and determine the effects of biodeterioration in such an environment on the analytical methods used to identify and compare synthetic fibers in the forensic science laboratory. 

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