Jens Laursen

Nutrients and heavy metals distribution in thermally treated pig manure

Ash from pig manure treated by combustion and thermal gasification was characterized and compared in terms of nutrient, i.e., potassium (K), phosphorus (P) and heavy metal, i.e., cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and zinc (Zn) contents. Total nutrient and metal concentrations were measured using energy dispersive X-ray fluorescence analysis. Acid (HNO3, H2SO4) and water-extractable concentrations were also measured both in non-classified ash and in selected ash particle size fractions using flame atomic absorption spectrometry and colorimetric spectrometry. Results indicate that ash from gasified manure contained more water-extractable K in comparison with combusted manure whereas the opposite was the case with respect to P. Heavy metals Ni, Cr and Cd were present in higher concentrations in the fine particle size fractions (< 30 µm of particle diameter), whereas K, P, Zn and Cu exhibited higher concentrations in the coarser particle size fractions (> 30 µm).

Quantification of zinc-porphyrin in dry-cured ham products by spectroscopic methods Comparison of absorption, fluorescence and X-ray fluorescence spectroscopy.

Zinc-protoporphyrin (Zn-pp), which has been identified as the major pigment in certain dry-cured meat products, was extracted with acetone/water (75%) and isolated from the following meat products: Parma ham, Iberian ham and dry-cured ham with added nitrite. The quantification of Zn-pp by electron absorption, fluorescence and X-ray fluorescence (XRF) spectroscopy was compared (concentration range used [Zn-pp]=0.8-9.7μM). All three hams were found to contain Zn-pp, and the results show no significant difference among the content of Zn-pp quantified by fluorescence, absorbance and X-ray fluorescence spectroscopy for Parma ham and Iberian ham. All three methods can be used for quantification of Zn-pp in acetone/water extracts of different ham types if the content is higher than 1.0ppm. For dry-cured ham with added nitrite, XRF was not applicable due to the low content of Zn-pp (<0.1ppm). In addition, XRF spectroscopy provides further information regarding other trace elements and can therefore be advantageous in this aspect. This study also focused on XRF determination of Fe in the extracts and as no detectable Fe was found in the three types of ham extracts investigated (limit of detection; Fe⩽1.8ppm), it allows the conclusion that iron containing pigments, e.g., heme, do not contribute to the noticeable red colour observed in some of the extracts.

Elements in Autopsy Liver Tissue Samples from Greenlandic Inuit and Danes. I. Sulphur, Chlorine, Potassium and Bromine measured by X-ray Fluorescence Spectrometry

The purpose of this study was to measure the content of the elements Sulphur (S), Chlorine (C1), Potassium (K) and Bromine (Br) in normal liver tissue samples from Greenlandic Inuit using X-ray fluorescence spectrometry, and compare the results with those obtained in normal liver tissue samples from Danes. Liver tissue sample were obtained at autopsy from 50 Greenlandic Inuit (27 men, 23 women) with a median age of 61 years (range 20-83) and from 74 Danes (44 men, 30 women) with a median age of 52 years (range 15-87). In Inuit, the content of elements given as median and (5-95 percentile) was: sulphur, 108.07 mmol/kg dry liver (86.78 - 169.44); chlorine, 92.16 mmol/kg dry liver (45.39-128.42); potassium, 181.66 mmol/kg dry liver (146.41-236.35); bromine, 0.0901 mmol/kg dry liver (0.0563-0.1589). In Danes, the corresponding values were: sulphur, 147.58 mmol/kg dry liver (70.41-236.81); chlorine, 96.95 mmol/kg dry liver (54.01-162.52); potassium, 198.40 mmol/kg dry liver (150.68-256.37); bromine, 0.1101 mmol/kg dry liver (0.0701 - 0.4203). None of the elements displayed any significant gender difference, neither in Inuit nor in Danes. Inuit had a lower liver content of sulphur (p < 0.0001), potassium (p < 0.008) and bromine (p < 0.002) as compared with Danes.

The association between content of the elements S, Cl, K, Fe, Cu, Zn and Br in normal and cirrhotic liver tissue from Danes and Greenlandic Inuit examined by dual hierarchical clustering analysis

PROJECT Meta-analysis of previous studies evaluating associations between content of elements sulphur (S), chlorine (Cl), potassium (K), iron (Fe), copper (Cu), zinc (Zn) and bromine (Br) in normal and cirrhotic autopsy liver tissue samples. PROCEDURE Normal liver samples from 45 Greenlandic Inuit, median age 60 years and from 71 Danes, median age 61 years. Cirrhotic liver samples from 27 Danes, median age 71 years. Element content was measured using X-ray fluorescence spectrometry. STATISTICS Dual hierarchical clustering analysis, creating a dual dendrogram, one clustering element contents according to calculated similarities, one clustering elements according to correlation coefficients between the element contents, both using Euclidian distance and Ward Procedure. RESULTS One dendrogram separated subjects in 7 clusters showing no differences in ethnicity, gender or age. The analysis discriminated between elements in normal and cirrhotic livers. The other dendrogram clustered elements in four clusters: sulphur and chlorine; copper and bromine; potassium and zinc; iron. There were significant correlations between the elements in normal liver samples: S was associated with Cl, K, Br and Zn; Cl with S and Br; K with S, Br and Zn; Cu with Br. Zn with S and K. Br with S, Cl, K and Cu. Fe did not show significant associations with any other element. CONCLUSIONS In contrast to simple statistical methods, which analyses content of elements separately one by one, dual hierarchical clustering analysis incorporates all elements at the same time and can be used to examine the linkage and interplay between multiple elements in tissue samples.

13Carbon and 15nitrogen isotopes in autopsy liver tissue samples from Greenlandic Inuit and Danes: consumption of marine versus terrestrial food

Background/Objectives:The content of 13C and 15N isotopes is higher in marine than in terrestrial food. 13C and 15N in human tissue therefore reflects the relative proportions of marine and terrestrial food consumed by the individual. The objective of this study was to measure 13C and 15N in liver tissue from Greenlandic Inuit and Danes.Subjects/Methods:Normal liver tissue was obtained at autopsy in 1992–1994 from 60 Inuit with a median age of 61 years (range 25–83) and in 1986 from 15 ethnic Danes with a median age of 84 years (range 66–93). By sieving, liver tissue was separated in a ‘cellular fraction’ and a ‘connective tissue fraction’. 13C and 15N in dry liver tissue was measured on a mass spectrometer. δ13C indicates the 13C content relative to the IAEA-CH-6 reference standard. δ15N indicates 15N content relative to the atmospheric nitrogen reference standard.Results:Inuit: median δ13C was −21.2‰ in cellular and −20.0‰ in connective tissue fractions (P=0.001). Median δ15N was 10.6‰ in both cellular and connective tissue fractions. Body mass index was negatively correlated with δ13C in the connective tissue fraction (rs=−0.42, P=0.057). Danes: median δ13C was −27.0‰ in cellular and −24.3‰ in connective tissue fractions (P=0.11). Median δ15N was 9.5‰ in cellular and 8.9‰ in connective tissue fractions (P=0.5). Inuit had higher δ13C than Danes in both cellular and connective tissue fractions (P<0.001) as well as higher δ15N in the cellular fraction (P=0.01).Conclusions:Inuit showed considerable variation in the ratio between marine and terrestrial food consumption, reflecting a vanishing hunter culture where elderly Inuit still adhere to the traditional hunters food with a high content of marine food, whereas the younger urbanized Inuit population consume food with a lower content of marine food and a higher content of terrestrial food. Danes consumed food of almost exclusively terrestrial origin. The present 13C and 15N analyses are in accordance with the dietary patterns obtained by dietary surveys.

Lead content in autopsy liver tissue in samples from Greenlandic Inuit and Danes

Objectives. To measure the quantity of lead (Pb) in liver tissue samples from Greenlandic Inuit, and compare the results with those obtained in Caucasian Danes. Study design. Observational, descriptive survey on environmental pathology. Methods. The setting was related to forensic medicine and hospitalised care in Nuuk, Ilulissat and Copenhagen. Participants were 50 Greenlandic Inuit (27 men) with a median age of 61 years (range 23–83) and 74 Danes (44 men) with a median age of 60 years (range 15–87). Liver tissue samples (normal by macroscopic and microscopic examination) were obtained at autopsy. Total liver lead content was measured by X-ray fluorescence spectrometry with a detection limit of 0.05 μmol/kg dry weight. Results. In the entire series, Inuit had higher liver lead contents than Danes (p < 0.0001). Inuit men had higher liver lead content than Inuit women (p = 0.02). In Danes, men tended to have higher liver lead contents than women, but the difference was insignificant. The median (5–95 percentile) lead content was 14.96 μmol/kg dry liver (4.83–74.80) in Inuit, and < 0.05 μmol/kg dry liver (< 0.05–29.44) in Danes. All Inuit had liver lead contents above the detection limit, whereas 60 Danes (81%) had liver lead content below the detection limit. There was a positive correlation between liver lead content and age in both Inuit (rs = 0.46, p = 0.002) and Danes (n = 14; rs = 0.71, p = 0.01). Inuit had higher hepatic lead indices (liver lead content divided by age) than Danes (p < 0.0001). In Inuit, median hepatic lead index was 0.258, being higher in men than in women (p = 0.02). In Danes, the median hepatic lead index was 0.001, again higher in men than in women (p = 0.03). Conclusions. Our results show a gender-related difference in hepatic lead content, i.e. Inuit men have higher liver lead contents than women. Furthermore, Inuit men and women have higher hepatic lead contents than Danish men and women. In both Inuit and Danes, the liver lead content increases with age. One reason for thehigh lead levels in Inuit may be ingestion of seabirds contaminated by lead shot.