by D Surabian · 2012 · Cited by 22 — For human biologists and forensic scientists, it includes the likelihood of a burial, condition and age of the bones, preserved bone suitable for DNA testing,
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Missing: bahamas pa

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U.S. Department of Agriculture Natural Resources Conservation Service CONNECTICUT Deborah Surabian, Soil Scientist Natural Resources Conservation Service Tolland, Connecticut December 2012 Preservation of Buried Human Remains in Soil This bone was located in a Hadley silt loam soil (map unit 10 5). Hadley soils are rated as having a high potential for preservation of buried remains .

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Table of Contents INTRODUCTION 1 PURPOSE .. 1 USE CONSTRAINTS . 1 FACTORS THAT INFLUENCE PRESERVATION . 2 BURIAL IN SOIL 3 EVALUATION CRITERIA . 4 CONNECTICUT CASE STUDY A .. 9 CONNEC TICUT CASE STUDY B . 10 CONNECTICUT CASE STUDY C 11 CONNECTICUT CASE STUDY D 13 RATINGS 15 Soil Potential Ratings . 15 Rating Classes . 15 Soil Potential Ratings by Map Unit . 16 TABLE 1 Preservation of Buried Human Remains in Soil by Map Unit, Soil S urvey of the State of Connecticut ..17 HANDLING FRESHLY EXC AVATED BONE AND ARTI FACTS IN HIGH POTENTIAL SO ILS 43 Connecticut General Statutes Title 10, Chapter 184a, Sec. 10 -388 on Human Remains .. 43 Treatment of Cultural Resources . 44 REFERENCES 45 APPENDIX 1 Preservation of Buried Human Remains in Soil , Soil Survey of the State of Connecticut ..51 APPENDIX 2 Documentation of NASIS Rules, Evaluations, and Properties 53

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– 1 – Introduction The Soil Survey of the State of Connecticut is a mode rn soil survey, incorporating current soil taxonomy and standards, addressing land use changes and urbanization, and compiled onto planimetric orthophoto base. The soil survey provides information on the location and characteristics of various kinds of soi ls within the state , along with interpretations or ratings of the soils based on soil properties. Soils are typically used by forensic science to link objects and persons with crime scenes. Many cadaver decomposition studies have since shown that process es in soil can also help to locate clandestine graves ( Carter et al., 2007 ) and estimate time since death ( Vass et al., 1992 ). If qualitative soil morphological information can help determine differential preservation, then it may become possible to make p redictions prior to excavation using soil survey information. Purpose This interpretation is a guide for identifying the likelihood of a burial in soil, the breakdown of a cadaver in contact with soil, and preservation of bone within the state of Connect icut. Soils are the physical context within which both archaeological and buried forensic evidence is found. Thus, it is important that both the archaeologist and forensic specialist understand some of the potential implications of different settings for t he preservation of buried human remains in soil . The information presented here will be useful to groups or individuals involved with archaeological and forensic investigations. For archaeologists, the effects may be dating the site, interpretation of the site composition, and site selection for preservation in situ (Jans et al., 2002 ). For human biologists and forensic scientists, it includes the likelihood of a burial, condition and age of the bones, preserved bone suitable for DNA testing, and an asses sment of the relative completeness of the skeleton. For law enforcement professionals, it could be used to understand a localized area for crime scene investigations. Among other things, this soil interpretation may help avoid costly exhumation activities in areas poorly suited to bone preservation, particularly if other methods of discovery are unavailable. Use Constraints In obtaining this data from NRCS, it is understood that you and/or your organization have the right to use them for any internal purp ose. This data is not designed for use as a primary tool, but may be used as a reference source. This data is not suitable for site -specific studies or litigation. Inappropriate applications would include a decision requiring on -site verification or prejud icial judgment based on the soil potential ratings information alone.

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– 3 – Burial in Soil A number of studies have been conducted to understand cadaver decomposition following burial in so il. It is generally accepted that burial of a cadaver decreases the rate of decomposition ( Mann, et al. , 1990 ; Rodriguez, 1997; Fiedler and Graw, 2003 ) and that t he decomposition of a cadaver in soil follows a sigmoidal pattern as shown in Figure 1 . This figure uses the six stages of cadaver decomposition proposed by Payne ( 1965): fresh, bloat, active deca y, advanced decay, dry, remains. Soils are likely most valuable to forensic taphonomy following the onset of advanced decay (Tibbet t and Carter, 2008 ). It is at this time that such factors as soil reaction (pH), temperature, and moisture will have the greatest role in decomposition. During the remains stage, p rediction of bone preservation in gravesoil is important to forensic scientists and archaeologica l research and in cultural resources management. Figure 1. A sigmoidal pattern of cadaver decomposition on the soil surface (solid line) and following a burial in soil (dash line) (Tibbett and Carter, 2008 ).

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Р4 РEvaluation Criteria This soil interpretation focuses on soil properties (depth of soil, soil reaction (pH), soil temperature, soil texture, rock fragment content, and soil moisture) that may infl uence the likelihood of a burial in soil, the breakdown of a cadaver in contact with soil, and preservation of bone. Depth of Burial and Difficulty Digging Generally, the burial of a cadaver in soil results in a decreased rate of decomposition as decomp osition one week in the air is equivalent to two weeks in water and eight weeks in soils ( CAP, 1986 ). Soils that are shallow to bedrock or restrictive material s make burials unlikely or else the burial is so shallow that decomposition is favored over prese rvation of bone. Typically, there is a greater level of biological activity at the surface and in the upper soil layers because of the greater availability of oxygen and food ( Lawson et al. 2000 ). In contrast, burial at depth may result in the material bei ng constantly or periodically below a water table which can restrict oxygen availability and decrease decomposition. Deep burials of more than 1 meter will restrict insect and other invertebrate activity, are unlikely to attract the attention of carnivor ous animals ( Krogman and Iscan, 1986 ), and are protected from the temperature fluctuations usually experienced in an ambient environment ( Galloway et al , 2001 ). Cadavers buried in soil usually require one to two years to completely skeletonize ( CAP, 1986 ). Thus, the depth of burial will influence the decomposition of organic materials with greater depth impeding decay ( Tibbett and Carter, 2008 ). Rock fragments at the surface and in the soil can interfere with burials due to the difficulty of digging. As t he number, size, and spacing of rock fragments incr eases on the surface of a soil Πincluding those that lie on the surface and those that are partly within the soi l but protrude from the ground Πdigging becomes more difficult and the likelihood of burial s will decrease. Soil Reaction ( pH) Correlations between osseous deterioration and soil acidity , as measure d by soil reaction (pH), were found to be significant. The pH of soil has the largest influence on bone preservation (Gordon and Buikstra, 1981 ), with preservation generally advantageous in soils above pH 5.3 and adverse in soils pH 5.3 or less. Soils containing a highly acidic pH will decompose bone rapi dly due to the dissolution of the inorganic matrix of hydroxy lapatite ( Nafte, 2000 ). Seventy percent of bone is made up of the ino rganic mineral hydroxy lapatite ( Wikipedia, 200 8). Hydroxy lapatite, t he mineral in bone co ntaining calcium and phosphates , is insoluble in water ( Morse, et al., 1983 ). However, i n the presence of an acid environment hydroxy lapatite will break down into soluble salts of calcium and phosphorus. If the so il is neutral or basic, a buried skeleton

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– 5 – may persist for centuries in good condition. In a corrosive soil environment it is clear that, irrespective of taphonom y, the outcome will be the same: catastrophic mineral dissolution, see Figure 2 (Niel sen-Marsh et al., 2007 ). Figure 2 illustrates the significant increases in bone deterioration related to an increase in soil acidity; the difference in the proportion of completely deteriorated bones more than doubles between soils with pH 6.0 and soils with pH 5. 5 (Nielsen -Marsh et al., 2007 ). Despite the overwhelming differences between sites, site environments, geography , and taphonomic history the bones examined fell into only f our major diagenetic categories : basic vs. acidic soils; human vs. animal remains (Nielsen -Marsh et al., 2007 ). Soil pH can also affect adipocere formation. Adipocere is a product of a chemical reaction and can be stable for long periods of time due to its considerable resist ance to bacterial action. This resistance allows for slower decomposition and is why it has been recorded on bodies that have been exhumed after 100 years. Mildly alkaline soil is the most favorable to adipocere formation. It can also form in mildly acidic environments, although highly acidic soils will inhibit its formation ( Tibbett and Carter, 2008 ). Adipocere is usually not apparent for about three months after death and becomes more prominent with the passage of time (CAP, 1986). It has been shown that the odor of adipocere is detectable by cadaver dogs searching for clandestine burials ( Rebmann et al, 2000 ). During the decay process, ammonium concentrations and carbon dioxide liberated by decarboxylation reactions cause an increase of the pH of soils s urrounding decomposing remains (Gill -King, 1997; Hopkins et al, 2000; Carter et al, 2008) . However, the correlation between the pH of the soil and ammonium is only noticed in acidic soils . Research revealed that no significant increase in pH is observed du ring decomposition in alkaline soil types (Stokes et al, 2009) . Figure 2. The influence of soil reaction ( pH) on bone survival. Black shading, bones absent; medium grey shading, bones with >33% porosity; light grey shading, bones with <33% porosity (Nielsen -Marsh et al., 2007 ). PAGE - 11 ============ - 6 - In Figure 3, the influence of pH on the solubilization of bone mineral was researched. The solubility values increase substantially with a decrease in pH , and though are temperature dependen t. In clan destine burials, it is a common belief that lime can be used to enhance the speed of decay, to reduce the likelihood of detecting a body, to destroy evidence, and that ultimately lime will lead to the rapid and total destruction of human re mains (Schotsmans et al, 2012). This belief couldn™t be more wrong. Research into the effects of lime in a burial environment has shown that lime decreases the rate of decomposition and results in the formation of adipocere after a 12 month period (Forbes et al, 2005). Lime can create pH levels greater than 12 and inhibit pathogens by controlling the environment required for bacterial growth. (National Lime Association, 2012). It can also destroy biological waste odors by providing free calcium ions that r eact and form complexes with odorous sulfur species such as hydrogen sulfide. (National Lime Association, 2012). Overall, the addition of lime can partially negated the effects of the soil environment; delaying the decaying process, restricting the release of cadaveric volatile organic compounds and therefore attracting fewer insects (Forbes et al, 2005). Soil Temperature Temperature is regarded as one of the most influential factors of decomposition ( Gill -King, 1997; Mann, et al. , 1990 ). It is currently known that the advanced decay and remains stages associated with a 150 pound human cadaver occur at 400 and 1285 accumulated degree days (sum of the average daily temperature), respectively ( Vass et al. 1992 ). Thus an avera ge summer daily temperature of 2 0 degrees Celsius would result in the onset of Figure 3 . Influence of pH on the solubility of bone calcium (Eeckhout, 1990) 301 KB – 59 Pages