The Distribution of Elements in 48 Canine Compact Bone Types Using Handheld X-Ray Fluorescence

90Sr and stable element levels in bones of brown bears: long-term trends in bear populations from Croatia and Poland

The aim of this study was to investigate the temporal trends and geographical differences in ⁹⁰Sr and stable element (Ba, Ca, Mn, Sr, Pb, Zn) levels in the bones of Croatian and Polish brown bear (Ursus arctos) populations. Experimental data suggest that in the decades after nuclear weapon tests and the Chernobyl accident, ⁹⁰Sr bone activity concentrations decreased from 352 to 11 Bq kg^-1 in the Croatian bear population (period 1982-2015) and from 831 to 27 Bq kg^-1 in Polish bears (period 1962-2020). Calculated effective and ecological half-lives were 9 and 13 years for Croatian bears, and 15 and 31 years for Polish bears, respectively. Different temporal trends were noted in levels of Ba, Mn, Pb and Zn between the two countries with majority of bones having lower Pb, Sr and Zn in Croatian than in Polish bears. Estimated values for the soil-to-bear transfer of ⁹⁰Sr were the same order of magnitude in the studied populations. Contrary to this, the estimated transfer of stable Sr was an order of magnitude lower for the Croatian bear population compared to Polish bears. The observed differences in soil-to-bear transfer between stable Sr and ⁹⁰Sr found for Croatian bears might suggest the need for careful consideration on the use of stable Sr data as an analogue for ⁹⁰Sr. To our knowledge, this is the first study that analysed ⁹⁰Sr activity in tissue of brown bears. As such, it provides insight into the fate and behaviour of one of the most relevant anthropogenic radionuclides at the top of the food chain.

Physical and chemical characterization of femur during and after body development period in male and female rats

The aim of this study was to determine the physical and chemical characteristics of the bone structures during four developmental periods. Forty Wistar Albino rats (20 male and 20 female) were divided into four groups including prepubertal period (group I), period between adolescence and adulthood (group II) and later (young adult period as group III and old adult period as group IV). The bones were analysed by morphometric measurements, XRF (X-ray fluorescence) analysis for mineral levels and BET analysis (Brunaurer-Emmett-Teller) for surface area and porosity. In morphometric measurements, the GL (greatest length) and the GLC (greatest length from caput femoris) values increased gradually from the first to the fourth group, and these values were higher in the males than the females. Phosphorus and calcium values were higher in the males in adult groups (third and fourth) compared to that for the females; however, they were higher in the females in groups up to adulthood (first and second). While the Ca/P ratio reached the highest value in the second group in the male, it decreased gradually afterwards. In females, the rate, which was close to each other in the first three groups, increased in the fourth group. Surface area size in the female and the male rats was the highest in the second group. In conclusion, changes in the rat bone structure during the development and adulthood periods of the body were revealed, and it was determined that the gender factor was effective in these changes.

Physical and chemical characterization of the femur during and after the body development period in male and female guinea pigs

In this study, it was aimed to reveal the physical and chemical characterization of the bone structures during body development periods (prepubertal period, period between adolescence and adulthood) and after (young adult period and old adult period) in male and female guinea pigs. In this study, 40 guinea pigs (20 male, 20 female) were used. Morphometric measurements, X-ray fluorescence (XRF) analysis for mineral levels, Brunauer-Emmett-Teller (BET) analysis for surface area, and porosity analysis were applied to the bones. The male guinea pigs had greater values than females in the other three categories, with the exception of the second group, when the females have higher values in morphometric measurements. Ca levels rose up to the third group, as did P levels in the males, peaking in the third group and declining in the fourth. As with phosphorus, there was a progressive rise in females from the first to the fourth group. Fe, Zn, and Sr elements had the greatest values in both genders in the first group. In all four groups, the females had greater Zn levels than males. The highest Ca/P ratio was found in the third male group and the fourth female group. This study revealed that adolescence, adulthood, and gender are effective in the physical and chemical characterization of bone structure in guinea pigs.

Elemental Distribution in Animal Carpal and Tarsal Bones Using Differences in X-ray Fluorescence Energy

Little is known as to whether different operating voltages of X-ray fluorescence (XRF) can affect the accuracy rate for species identification. Here, we have addressed this question by comparing the rate of correct species identification using the elemental composition of either the carpal or tarsal bone obtained from a determination of the different energy values of XRF at 15 and 50 kV using energy-dispersive XRF (ED-XRF). Carpal bones were taken from 16 species and tarsal bones from 11 of these species. The data on the elemental profiles were analyzed by stepwise discriminant analysis for species discrimination. The classification results indicated that 94.1% and 63.7% of the originally grouped cases were correctly classified as carpal bones using 15 kV and 50 kV, respectively. Additionally, 69.4% and 77.3% of the originally grouped cases were correctly classified as tarsal bones using 15 kV and 50 kV, respectively. When the datasets of the elemental profiles obtained using two operating voltages were gathered, the classification results of the prediction rate appeared to be more accurate at 89.7% and 90.7% in the carpal and tarsal bones, respectively. In conclusion, our findings suggest that the elemental profiles of bones obtained using two operating voltages could effectively facilitate accurate species discrimination.

Diagnostic Value of Energy Dispersive Hand-Held X-ray Fluorescence Spectrometry in Determining Trace Element Concentrations in Ovine Liver

There are no data available on the use of hand-held X-ray fluorescence (XRF) spectrometry to determine trace element concentrations in veterinary diagnostics. The hand-held XRF spectrometer is easy to use and does not require extensive training for the operator. In Sub-Saharan Africa with few centralised analytical laboratories equipped with expensive apparatus or mass spectrometry capabilities, trace element analysis using the hand-held XRF spectrometer provides an alternative. The objective of this study was to compare ovine hepatic copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se) and zinc (Zn) concentrations as obtained with the hand-held XRF spectrometer to those of a reference laboratory using inductively coupled plasma mass spectrometry (ICP-MS). Thirty ovine livers were obtained from an abattoir; prepared as wet blended and oven-dried samples and analysed. Bayesian correlation was used to assess the correspondence between results from the XRF and ICP-MS analyses. The oven-dried preparation procedure for XRF provided the best correlation with the ICP-MS data. The correlations for Cu and Zn were strong and the XRF method may represent a suitable substitute for ICP-MS analysis. For Mn and Fe the correlations were moderately strong and the XRF method may be suitable. For Mo, the correlation was weak and XRF cannot be recommended. Selenium could not be detected in samples prepared by either method. Hand-held XRF spectrometry was a practical method to determine liver concentrations of specific trace elements under African conditions and may significantly reduce the turn-around time of analysis, but unfortunately the apparatus is expensive.

Trace and macro elements in the femoral bone as indicators of long-term environmental exposure to toxic metals in European brown bear (Ursus arctos) from Croatia

We explored the long-term accumulation of aluminium, strontium, cadmium and lead in the compact and trabecular bone of the femoral epiphysis, metaphysis and diaphysis in 41 brown bears (Ursus arctos) from Croatia. Also, we assessed their influence on macro and trace elements (sodium, magnesium, phosphorus, potassium, calcium, manganese, iron, cobalt, copper, zinc and barium) in bears' bone. There were no sex differences in element levels in general, while age was associated with bone length and levels of all elements, except for cadmium. Elements had different levels depending on the part of the bone sampled. More pronounced differences were observed between the compact and trabecular regions, with higher levels of majority of elements found in compact bone. Moderate to high associations (Spearman coefficient, r_S = 0.59-0.97) were confirmed between calcium and potassium, magnesium, phosphorus, manganese, cobalt, zinc, strontium and lead. Lead levels in the bone were below those known to cause adverse health effects, but in 4 of 41 animals they exceeded baseline levels for domestic animals. The femoral bone of the brown bear reflected the accumulative nature of lead and strontium well, as it did the impairment of bone-forming essential element levels associated with these two elements. However, the distribution pattern of elements along the bone was not uniform, so additional care should be taken when choosing on the part of the bone sampled.

Elemental classification of the tusks of dugong (Dugong dugong) by HH-XRF analysis and comparison with other species

The elemental composition was investigated and applied for identifying the sex and habitat of dugongs, in addition to distinguishing dugong tusks and teeth from other animal wildlife materials such as Asian elephant (Elephas maximus) tusks and tiger (Panthera tigris tigris) canine teeth. A total of 43 dugong tusks, 60 dugong teeth, 40 dolphin teeth, 1 whale tooth, 40 Asian elephant tusks and 20 tiger canine teeth were included in the study. Elemental analyses were conducted using a handheld X-ray fluorescence analyzer (HH-XRF). There was no significant difference in the elemental composition of male and female dugong tusks, whereas the overall accuracy for identifying habitat (the Andaman Sea and the Gulf of Thailand) was high (88.1%). Dolphin teeth were able to be correctly predicted 100% of the time. Furthermore, we demonstrated a discrepancy in elemental composition among dugong tusks, Asian elephant tusks and tiger canine teeth, and provided a high correct prediction rate among these species of 98.2%. Here, we demonstrate the feasible use of HH-XRF for preliminary species classification and habitat determination prior to using more advanced techniques such as molecular biology.

Variation in elemental composition of human teeth and its application for feasible species identification

Identifying human remains is a primary task in forensic science. In this study, we propose a possible new technique, handheld X-ray fluorescence (HHXRF), for determining whether a suspected tooth is an authentic human tooth. A total of 444 teeth obtained from 111 human skulls (male=62, female=49) aged between 30-67 years (51.81±8.37 years) were used as subjects. The teeth were scanned by HHXRF to acquire their elemental profile. Differences in elemental composition were analyzed for different tooth positions (numbers 1-32), between crown and root, and between sexes (male and female); also, the proportion of elements in relation to different human ages was examined. Teeth from 20 different animal species, serving as non-human teeth samples, were used to distinguish between human and non-human teeth through a stepwise discriminant analysis. Our results revealed that different tooth positions, different regions (crown and root) of a tooth, and different sexes demonstrated disparities in the proportion of several elements. The accuracy rate of predicting sex based on the elemental profile of human teeth was 65.5%. Likewise, a dissimilar distribution of elements between human and non-human teeth was observed, leading to a high degree of correctness of 83.2% for distinguishing them. In conclusion, elemental analysis by HHXRF could serve as a promising candidate tool for identifying human teeth in forensic science, but is ineffective for sex determination.