Human bone range

Tabic 1.1. Amino acids per thousand residues for standard type 1 collagen and 15 human bone collagen samples from St. Thomas Church cemetery. Samples are identified by burial numlter (Bx) followed by age midpoint for subadults and age range for adults in parentheses. For example, B17(0) refers to burial 17 who was aged as a newborn. 

Human bone strontium levels (Fig. 1.5) are within the range that is expeeted for that region (Katzenberg 1984). The sample size is small and uneven with only three females and one subadult so it is not possible to comment on sex or age differences except to say that the highest Sr content was found in the sample from a child aged around 9 2 years. 

The study of obsidian by NAA has proved to be particularly fruitful because of the relatively limited number of sources and the extent to which it was traded (Beardsley et al. 1996, Cook 1995, Darling and Hayashida 1995, Kuzmin et al. 2002, Leach 1996). Studies have also extended to include other volcanic materials such as pumice (Bichler et al. 1997, Peltz et al. 1999). NAA has also been used for the analysis of flint as OES is insensitive and not reproducible due to the effect of the high silica content, and AAS requires significant sample preparation (Aspinall and Feather 1972). The wide range of appropriate materials extends to organic materials such as human bone (Farnum et al. 1995), and its exceptional sensitivity to trace elements has led to its wide use in geochemistry (for example in determining trace [ppb] contaminants in waters) and more recently in forensic chemistry. 

The normal level of aluminum in adult human lungs is about 20 mg/kg wet weight (w/w) and increases with age due to buildup reported normal levels in human bone tissue range from 5 to 10 mg/kg (Allfey 1980 Allfey et al. 1980 Coumot-Witmer et al. 1981 Flendrig et al. 1976 Hamilton et al. 1972/73 Tipton and Cook 1963). Low aluminum levels (0.3-0.8 mg/kg w/w) are found in most soft tissue organs, other than the lungs (Hamilton et al. 1972/73 Tipton and Cook 1963). 

Figure 5 Expected ranges of carbon isotopic composition of human bone for eight possible diets.

Figure 6. Carbon isotopic analyses of archaeological human bone compared to the theoretical model for herbivores, the theoretical model for carnivores, and the expected ranges of carbon isotopic composition of human bone for eight possible diets (see Figure 5 for identification of diet types).

The amount of strontium and barium in bones and teeth differs by two orders of magnitude (Table 1). Human strontium and barium levels in bones and teeth exist in a bimodal literature that derives from an interest in the incorporation of °Sr in the 1950s, and a more recent group of studies that focus on strontium s effect on mineralization. A wide range in strontium content in human bone is reported in groups of studies that are fifty years apart, but, in general, modem human bone and enamel tends to have strontium content <200 ppm, while barium content is commonly reported at less than 10 ppm. The amount of strontium in a normal human diet ranges from 0.023 to 0.046 mmol/Sr/day (Marie et al. 2001), and when administered with calcium, strontium is adsorbed to a lesser extent (Milsom et al. 1987). 

Microscale hydroxyapatite (size distribution of the powder 3.0 0.1 J,m) similar to the innate hydroxyapatite in human bone (57.0 and 41.4 wt% of CaO and P2O5, respectively Ca/P molar ratio 1.67) was used to fabricate films after suspension in solutions of 400 kDa chitosan. Becanse of the well-dispersed hydroxyapatite powders in the polymer matrix, the film appeared white and flexible with a transmittance <20% in the visible range. The observation under the SEM ensnred monodis-persity of the films. Good monodispersity improved the homogeneity and uniformity of the film, and prevented phase separation resulting in unwanted microcracks (Kim et al. 2009). 

Standard stress-strain curves for both aerogels under uniaxial compression show a first linear region up to 4% strain making it possible to estimate an elastic modulus of 72.4 MPa for S20Ca20, which is close to the low range for cancellous human bone (50-500 MPa). The strain to rupture occurred at 17% and the corresponding stress was 9 MPa. 

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