Trace Element Reference Values Research Articles

Scientific rationale for the indicators of biological urine monitoring in adolescents in Kazan City

BACKGROUND: Biomonitoring is crucial for assessing the level of pollution in a population, identifying risks and studying the impact of changes in technology. Knowledge of the reference values of trace elements in biological material is critical in comparing exposed with non-exposed groups and accurate. The control values of trace elements are crucial for ensuring public health and occupational safety. AIM: To study and analyze concentrations of priority chemical pollutants in the urine of adolescents aged 14–17 years in three zones in Kazan City and determine reference values for this age group. MATERIALS AND METHODS: The concentration of elements in urine of 276 adolescents aged 14–17 years was measured by inductively coupled plasma mass spectrometry. RESULTS: The upper 95 percentiles and their confidence intervals (RV95) were determined, which established the upper limit of the current background exposure to adolescents for 12 biomarkers, interpreted as “conditional” reference values for this age group. The following reference values for adolescents in Kazan City were obtained: Al, 12.80 µg/L; Cr, 1.02 µg/L; Mn, 3.53 µg/L; Hg, 0.65 µg/L; Cu, 110.91 µg/L, and Ni, 8.72 µg/L. In adolescents, the highest level of exceedance over background values was observed in zones 1 and 2 (Kirovsky and Privolzhsky Districts): Al exceeded by 1.4 times, Cr by 1.3 times in zone 1 (Kirovsky District), Mn by 1.5 times, Hg by 1.3 times, and Cu by 1.14 times in zone 2 (Privolzhsky district).The results are of interest for further analysis and identification of interrelations in the territory of the Republic of Tatarstan, Russia, where exposure levels may vary between regions or separate subgroups living in the same territory. CONCLUSION: Research in the field of biomonitoring in Kazan established the levels of exposure to toxic elements among the studied population and provided means for comparing exposure for further research by population groups by age, sex, and ethnicity. Moreover, biomonitoring results can be used to determine research priorities, measure exposure trends over time, and verify effectiveness of individual measures to combat pollution and other measures in the field of the environment and public health. The study presents modern technologies for assessing exposure to chemical pollutants using human biomonitoring methods and demonstrates its advantages.

Reference values for plasma and urine trace elements in a Swiss population-based cohort.

Trace elements (TEs) are ubiquitous. TE concentrations vary among individuals and countries, depending on factors such as living area, workplaces and diet. Deficit or excessive TEs concentrations have consequences on the proper functioning of human organism so their biomonitoring is important. The aim of this project was to provide reference values for TEs concentrations in the Swiss population. The 1,078 participants to the SKiPOGH cohort included in this study were aged 18-90 years. Their 24-h urine and/or plasma samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine 24 TEs concentrations: Ag, Al, As, Be, Bi, Cd, Co, Cr, Cu, Hg, I, Li, Mn, Mo, Ni, Pb, Pd, Pt, Sb, Se, Sn, Tl, V and Zn. Statistical tests were performed to evaluate the influence of covariates (sex, age, BMI, smoking) on these results. Reference intervals for the Swiss adult population were also defined. TEs concentrations were obtained for respectively 994 and 903 persons in plasma and urine matrices. It was possible to define percentiles of interest (P50 and P95) for almost all the TEs. Differences in TEs distribution between men and women were noticed in both matrices; age was also a cofactor. This first Swiss biomonitoring of a large TEs-panel offers reference values in plasma and in urine for the Swiss population. The results obtained in this study were generally in line with clinical recommendations and comparable to levels reported in other population-based surveys.

The study of blood serum trace elements in comparison with the structural and functional characteristics of goiter and the carriage of antithyroid antibodies in some regions of Russia

The study of the sufficiency with essential trace elements in the context of thyroid pathology is especially relevant, since the development and progression of thyroid diseases have various pathogenetic mechanisms, which largest proportion is provoked by insufficient intake of key trace elements, primarily iodine. The aim of the research was obtaining primary data on the sufficiency with essential trace elements of the population in the some regions of the Russian Federation, comparing the data obtained with the prevalence of goiter and the carriage of antibodies to thyroid peroxidase (AT-TPO). Material and methods. The Cross-Sectional Population Study was conducted in medical institutions of the Republics of Crimea, Republics of Tuva and Bryansk region (persons applied for outpatient consultations). The scope of the study was 387 people aged 18 to 65 years (the average age was 40±5 years). All of them underwent: collection of medical history, endocrinologist examination with palpation of the thyroid gland (TG), ultrasound examination of TG, blood sampling to assess the levels of thyroid-stimulating hormone (TSH), AT-TPO, iodine, selenium, zinc. Ultrasound of the TG was performed in the supine position using a portable ultrasound machine LOGIQe (China) with a multi-frequency linear probe 10-15 MHz. During the study, the volume of the thyroid gland, the presence of nodular formations and their characteristics according to the TIRADS classification, TG structure and its echogenicity were assessed. Iodine, selenium and zinc level were measured using tandem mass spectrometry with ionization in inductively coupled plasma (Agilent 8900 ICP-MS Triple Quad). TSH and Ab-TPO were determined by chemiluminescent immunoassay on the Architect i2000 automatic analyzer. Results. All regions are comparable in terms of iodine availability, but differ in the severity of natural iodine deficiency. The median concentration of iodine in blood serum practically coincided in all three regions, amounting to 39.8 μg/l in the Republic of Crimea; 38.8 μg/l in the Republic of Tyva and 43.4 μg/l in the Bryansk region. Comparing these results with foreign data, as well as with our results on urinary iodine level, obtained by routine cerium-arsenite method, we can assume that iodine content in blood serum corresponded to the lower limit of the normal target values. The median concentration of selenium in blood serum also practically coincided in all three regions, amounting to 68.2, 72.1 and 62.8 μg/l, respectively, and probably meets the criteria for optimality. The median serum concentration of zinc in Bryansk region residents corresponded to a deficiency (491.3 μg/l) and was significantly lower compared to the indicator in the Republics of Crimea and Tyva (1633.2 and 1667.6 μg/l, respectively, values above optimal). Among the examined, the proportion of people with AB-TPO carriership was 23.5% (Republic of Crimea - 20.9%, Republic of Tuva - 26.4%, Bryansk region - 20.7%), with impaired thyroid function - 9.6% (6.2% - hypothyroidism, 3.4% - thyrotoxicosis). The frequency of goiter varied from 10 to 13.8%. There were no significant differences in the frequency of occurrence, ultrasonic characteristics of goiter and thyroid nodules by regions. Conclusion. However, the results obtained do not allow to unequivocally judge the absence of micronutrient deficiency in the population of the regions of the Russian Federation, since used the ICP-MS method requires the development of our own reference values of trace elements; in the absence of the latter, data from similar foreign studies were taken as standards. In addition, in further studies it will be important to take into account additional criteria for assessing trace element deficiency, for example, activity of superoxide dismutase and alkaline phosphatase as indirect markers of zinc deficiency, etc. Correlation between blood serum concentration of trace elements and the frequency and structural characteristics of goiter, the carriage of Ab-TPO, and dysfunction of the TG was not revealed.

Trace Element Levels in the Serum of Hermann´s Tortoises (<i>Testudo hermanni</i>)

Up to now, blood reference values for trace elements (zinc, copper, iodine, iron, selenium and manganese) in the serum of Testudo spp. have not been established. Most studies concerning trace element levels in blood of reptile’s regard environmental pollution esp. concerning selenium. In the present study levels of iron, copper, iodine, zinc, selenium and manganese were evaluated in 130 blood samples of clinically healthy Hermann´s Tortoises (Testudo hermanni), originating from pet tortoises in Germany (n= 64), extensively kept captive-hatched tortoises from Turkey (n=20), and from free-ranging specimens of two locations in France (n=46). The French habitats differ in the nature of the soils, one being low in lime and another high in lime. The levels of trace elements in the blood were compared between the different groups and to the levels of trace elements in the respective feed rations resp. food plants. The aim was to check the correlation between origin, husbandry, feeding and sex on the levels of trace elements in the blood. Blood levels of trace elements, regardless of origin, gender, or diet, generally showed a wide range. Also there existed a poor correlation to contents in diet concerning iron, selenium, and manganese, but a statistically significant correlation to zinc, copper and iodine. Preliminary reference values of zinc, iodine and copper can be a useful tool to diagnose nutrient deficiencies, poisoning and deficiency symptoms in Testudo hermanni.

Reference values of trace elements in blood and/or plasma in adults living in Belgium.

Trace elements (TEs) from natural and anthropogenic sources are ubiquitous. Essential or not, their relevance for human health and disease is constantly expanding. Biological monitoring is a widely integrated tool in risk assessment both in occupational and environmental settings. However, the determination of appropriate and accurate reference values in the (specific) population is a prerequisite for a correct interpretation of biomonitoring data. This study aimed at determining the reference distribution for TEs (Al, As, Sb, Be, Bi, Cd, Co, Cu, Mn, Hg, Mo, Ni, Pb, Se, Tl, Sn, V, Zn) in the blood and/or plasma of the adult population in Belgium. Blood and plasma samples were analyzed for 178 males and 202 females, recruited according to an a priori selection procedure, by inductively coupled plasma mass spectrometry (ICP-MS). Reference values were established with high confidence for AsT, Cd, Cu, HgT, Mn, Mo, Pb, Sn, Se, Tl and Zn. Compared to previously published data in the Belgian population, a decreasing time trend is observed for Zn, Cd and Pb. Globally, the results also indicate that the current exposure levels to TEs in the Belgian population are similar to those from other recent national surveys. These reference values and limits obtained through validated analytical and statistical methods will be useful for future occupational and/or environmental surveys. They will contribute to decision-making concerning both public health policies but also exposure assessments on an individual scale.

Fast and effective simultaneous determination of metals in soil samples by ultrasound-assisted extraction and flame atomic absorption spectrometry: assessment of trace elements contamination in agricultural and native forest soils from Paraná - Brazil

This study proposes a simple and effective method for determination of Al, Cd, Cu, Ni, and Zn in soil samples, associating ultrasound-assisted extraction and flame atomic absorption spectrometry (FAAS). Ultrasound-assisted extraction conditions were optimized using a central composite design. This method required small volumes of HCl, HNO3, and HF as an extraction solvent blend to ensure effective analyte extraction. Limits of detection and quantification were determined to assess the minimum accurate concentration of the studied elements that can be detected and quantified in a soil sample. Therefore, the ultrasound-assisted extractionwas concluded as a simple and straightforward pretreatment technique to determine Al, Cd, Cu, Ni, and Zn concentrations in soil samples. Eight sites of agricultural and native forest areas of the city of Ponta Grossa and Guarapuava, State of Paraná, Brazil, were evaluated for metals, and compared with the reference values for trace elements provided by the Brazilian National Environment Council. Environmental assessment of soils from those eight sites was accomplished through Igeo, EF, CF, and PLI parameters, which aimed at the evaluation of agricultural sites in comparison with adjacent natural forest sites with no history of anthropogenic mobilization to determine the degree of the contribution of anthropogenic sources to metal concentrations. According to the Igeo, EF, and CF parameters, all sites were classified as unpolluted to moderately polluted and none or minor enrichment due to anthropogenic activities were noticed. PLI parameter evaluated the concentration of all studied metals in soils to stipulate an order of contamination, which was concluded as site 8 <site 4 <site 3 <site 7 <site 2 <site 6 <site 1 <site 5 for the sites under study.

Determination of traces of As, Cd, Cr, Hg, Mn, Ni, Sb, Se, Sn and Pb in human hair by triple quadrupole ICP-MS

ABSTRACTWith the wide range of metallic contaminants discharged in the environment, studying the human health requires a growing number of elements to be monitored in biological samples. Hair analysis has been suggested as a suitable tool for biomonitoring environmental and occupational exposure to toxic elements. This study describes a method for the determination of 10 trace elements in hair samples using ICP-QQQ-MS. Combining the power of the MS/MS high-energy Helium mode with the MS/MS O2 mass-shift mode, the method offers great analytical performances with detection limits reaching 0.0014 µg g−1 for As, 0.0016 µg g−1 for Cd, 0.012 µg g−1 for Cr, 0.0035 µg g−1 for Hg, 0.0055 µg g−1 for Mn, 0.10 µg g−1 for Ni, 0.0012 µg g−1 for Sb, 0.0083 µg g−1 for Sn, 0.011 µg g−1 for Se and Pb. The accuracy of the method was tested on a human hair ERM® certified reference material. Percent recoveries varied from 91.3% and 106.9% being always in the acceptance range of 90–110%. For all analysed elements, RSD% of repeatability ranged between 0.6% and 9.0% and those of intermediate precision did not exceed the limit of 20% being always lower than 10% (except for As). The proposed method was applied for the determination of trace elements in hair samples from 20 unexposed subjects. The geometric mean levels were as follows: Cr 0.28 µg g−1, Mn 0.30 µg g−1, Sn 1.04µg g−1, Sb 0.07 µg g−1, Hg 0.42 µg g−1, As 0.02 µg g−1, Cd 0.03 µg g−1, Ni 0.51 µg g−1, Se 0.45 µg g−1 and Pb 1.83 µg g−1. Element concentrations were in the same range with the reported data. The reported results may be useful for environmental exposure assessment or comparisons studies when establishing reference values of trace elements in exposed population.

Selected trace elements concentrations in pregnancy and their possible role - literature review.

The aim of this study was to review the role of selected trace elements in pregnancy and fetal development. Citations related to the role of iron (Fe), zinc (Zn), manganese (Mn), copper (Cu) and selenium (Se) during pregnancy were searched in PubMed, Medline, Web of Science, using keywords and MeSH terms. Inadequate supply of trace elements can cause abnormalities of fetal development and predispose a child to disorders later on in life. Trace elements are the key elements of complex enzymes responsible for the modulation of the antioxidant defense system of the organism. It has been suggested that there is a correlation between reduced levels of trace elements essential for antioxidant function in the body of pregnant women, and an increased risk of developing preeclampsia. Trace elements are components of numerous regulatory enzymes and hormones essential to the division and differentiation of fetal cells and their further development. Mineral deficiencies in pregnant women can cause birth defects of the central nervous system, and growth disorders. Future research should be directed to explain the interaction between trace elements, and establish the optimum levels of macro and micronutrients supplementation, as well as determine the reference values for trace elements in the maternal serum, umbilical cord blood and amniotic fluid.

Reference Values of 14 Serum Trace Elements for Pregnant Chinese Women: A Cross-Sectional Study in the China Nutrition and Health Survey 2010-2012.

The development of reference values of trace elements is recognized as a fundamental prerequisite for the assessment of trace element nutritional status and health risks. In this study, a total of 1400 pregnant women aged 27.0 ± 4.5 years were randomly selected from the China Nutrition and Health Survey 2010–2012 (CNHS 2010–2012). The concentrations of 14 serum trace elements were determined by high-resolution inductively coupled plasma mass spectrometry. Reference values were calculated covering the central 95% reference intervals (P2.5–P97.5) after excluding outliers by Dixon’s test. The overall reference values of serum trace elements were 131.5 (55.8-265.0 μg/dL for iron (Fe), 195.5 (107.0–362.4) μg/dL for copper (Cu), 74.0 (51.8–111.3) μg/dL for zinc (Zn), 22.3 (14.0–62.0) μg/dL for rubidium (Rb), 72.2 (39.9–111.6) μg/L for selenium (Se), 45.9 (23.8-104.3) μg/L for strontium (Sr), 1.8 (1.2–3.6) μg/L for molybdenum (Mo), 2.4 (1.2–8.4) μg/L for manganese (Mn), 1.9 (0.6–9.0) ng/L for lead (Pb), 1.1 (0.3-5.6) ng/L for arsenic (As), 835.6 (219.8–4287.7) ng/L for chromium (Cr), 337.9 (57.0–1130.0) ng/L for cobalt (Co), 193.2 (23.6–2323.1) ng/L for vanadium (V), and 133.7 (72.1–595.1) ng/L for cadmium (Cd). Furthermore, some significant differences in serum trace element reference values were observed between different groupings of age intervals, residences, anthropometric status, and duration of pregnancy. We found that serum Fe, Zn, and Se concentrations significantly decreased, whereas serum Cu, Sr, and Co concentrations elevated progressively compared with reference values of 14 serum trace elements in pregnant Chinese women. The reference values of serum trace elements established could play a key role in the following nutritional status and health risk assessment.

Natural concentrations and reference values for trace elements in soils of a tropical volcanic archipelago

Fernando de Noronha is a small volcanic archipelago in the Southern Atlantic, some 350km NE of the city of Natal in NE Brazil. These remote volcanic islands represent a largely pristine environment, distant from sources of anthropogenic contamination. This study was carried out to determine the natural concentrations of Ag, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, V and Zn in the A and B horizons of soils of Fernando de Noronha. The aims of the study were twofold: determine whether there is a relationship between the bedrock geology and soils and to establish quality reference values for soils from Fernando de Noronha. Soil samples were subjected to acid digestion by the USEPA method 3051A, and metals were determined by inductively coupled plasma emission spectrophotometry. The results showed that the trace element distribution largely reflects the geochemistry of the underlying volcanic rocks of the Remedios and Quixaba Formations. The results demonstrate that the concentrations of Ba, Cr, Zn, Ni and Cu from the soils of the volcanic Fernando de Noronha archipelago are higher than those found in soils from continental Brazil. However, concentrations of Ni, Cu and Co are lower in soils of the archipelago as compared to other volcanic islands throughout the world. The elevated trace element concentrations of the volcanic parent material of Fernando de Noronha soils seem to be the main factor governing the relatively high natural concentrations of trace elements.

Human biomonitoring reference values for metals and trace elements in blood and urine derived from the Canadian Health Measures Survey 2007-2013.

Human biomonitoring reference values are statistical estimates that indicate the upper margin of background exposure to a given chemical at a given time. Nationally representative human biomonitoring data on 176 chemicals, including several metals and trace elements, are available in Canada from 2007 to 2013 through the Canadian Health Measures Survey (CHMS). In this work, we used a systematic approach based on the reference interval concept proposed by the International Federation of Clinical Chemistry and Laboratory Medicine and the International Union of Pure and Applied Chemistry to derive reference values (RV95s) for metals and trace elements. These RV95s were derived for blood and urine matrices in the general Canadian population based on the latest biomonitoring data from the CHMS. Biomarkers were chosen based on specific selection criteria, including widespread detection in Canadians (≥66% detection rate). Reference populations were created for each biomarker by applying appropriate exclusion criteria. Age and sex were evaluated as possible partitioning criteria and separate RV95s were derived for the sub-populations in cases where partitioning was deemed necessary. The RV95s for metals and trace elements in blood ranged from 0.18μg/L for cadmium in young children aged 3-5 years to 7900μg/L for zinc in males aged 20-79 years. In the case of urinary biomarkers, the RV95s ranged from 0.17μg/L for antimony in the total population aged 3-79 years to 1400mg/L for fluoride in adults aged 20-79 years. These RV95s represent the first set of reference values for metals and trace elements in the general Canadian population. We compare the RV95s from other countries where available and discuss factors that could influence such comparisons.

Comparison of the nutritional and toxicological reference values of trace elements in edible marine fish species consumed by the population in Rio De Janeiro State, Brazil

The present study estimated the human daily and weekly intake of inorganic elements due to consumption of fish in Rio de Janeiro state and the associated potential health risks posed by some toxic elements. All samples analyzed had values of Cd and Pb below the Maximum Tolerable Limits of 3.0 mg kg−1 for Pb and 1.0 mg kg−1 for Cd; only Mugil cephalus, Cynoscion leiarchus and Caranx crysos had As concentrations below 1 mg kg−1, maximum limit established by Brazilian legislation. The higher values of Cd and Pb correspond to 0.22% of PTWI and the higher value of As corresponds to 8.6% of PTWI. None of the studied species showed values higher than PTWI. The higher values of Cu EDI found in Pomatomus numida correspond to 33.3% of RDA; Fe in Salmo salar and Genypterus brasiliensis corresponds to 4.3% of EDI; Mn in Sardinella brasiliensis corresponds to 7.4% of EDI; Zn in S. salar corresponds to 13.2% of EDI and Se in S. salar corresponds to 20.6% of EDI. Some species can be a good source of inorganic elements. For risk assessment, it is important to assess specific eating habits of each region to avoid underestimating the data.

Determination of 16 Selected Trace Elements in Children Plasma from China Economical Developed Rural Areas Using High Resolution Magnetic Sector Inductively Coupled Mass Spectrometry

A rapid, accurate, and high performance method of high resolution sector field inductively coupled plasma mass spectrometry (HR-ICP-MS) combined with a small-size sample (0.1 mL) preparation was established. The method was validated and applied for the determination of 16 selected plasma trace elements (Fe, Cu, Zn, Rb, B, Al, Se, Sr, V, Cr, Mn, Co, As, Mo, Cd, and Pb). The linear working ranges were over three intervals, 0-1 μg/L, 0–10 μg/L and 0–100 μg/L. Correlation coefficients (R 2) ranged from 0.9957 to 0.9999 and the limits of quantification (LOQ) ranged from 0.02 μg/L (Rb) to 1.89 μg/L (Se). The trueness (or recovery) spanned from 89.82% (Al) to 119.15% (Se) and precision expressed by the relative standard deviation (RSD %) for intra-day ranging from 1.1% (Zn) to 9.0% (Se), while ranged from 3.7% (Fe) to 12.7% (Al) for interday. A total of 440 plasma samples were collected from Chinese National Nutrition and Health Survey Project 2002 (CNNHS 2002), which represented the status of plasma trace elements for the children aged 3–12 years from China economical developed rural areas. The concentrations of 16 trace elements were summarized and compared by age groups and gender, which can be used as one of the basic components for the formulation of the baseline reference values of trace elements for the children in 2002.

BLOOD VITAMINS AND TRACE ELEMENTS IN NORTHERN-EAST AFRICAN CHEETAHS (ACINONYX JUBATUS SOEMMERINGII) IN CAPTIVITY IN THE MIDDLE EAST

There are few published data regarding the endangered Northern-East African cheetah (Acinonyx jubatus soemmeringii), held in captivity in the Middle East and Europe. Studies have demonstrated a high incidence of disease in captive cheetahs, in which vitamin and trace element imbalances have often been implicated. Blood vitamin and trace element reference values in cheetahs merit further investigation. In this study, blood samples were opportunistically collected from apparently healthy A. j. soemmeringii from two collections (A and B) with successful breeding programs in the United Arab Emirates. The cheetahs were fed whole prey of mixed species (and, in Collection B, goat muscle and bone as well) dusted with vitamin and mineral supplements. Mean serum vitamin and trace element values (for cheetahs > 4 mo in age) were as follows: vitamin A (retinol), 2.20 microM/L (n = 27); vitamin B1, 0.0818 microM/L (n = 45); vitamin C, 28.6 microM/L (n=10); vitamin E (alpha-tocopherol), 35.6 microM/L (n = 27); copper (Cu), 12.53 microM/L (n = 27); selenium (Se), 3.10 microM/L (n = 27); and zinc (Zn), 10.87 microM/L (n = 27). Mean values of vitamin A, vitamin E, Cu, and Zn fell within ranges of published cheetah mean values, and mean Se was lower than range values for cheetahs presented in one previous study; blood vitamin B1 and vitamin C values of cheetahs have not previously been published. The values were taken to indicate that the cheetahs' nutritional status was adequate with regard to those nutrients analyzed. Serum vitamin E was particularly high in cheetahs fed fresh whole prey, and on this basis vitamin E supplementation of fresh whole prey appeared to have been unnecessary. There were differences (P < 0.05) between collections in serum vitamin B1, vitamin E, Cu, and 10 other hematologic and biochemical parameters. Nine hematologic and blood biochemical parameters differed among age categories.

Risk–benefit analysis of mineral intakes: case studies on copper and iron

Dietary reference values for essential trace elements are designed to meet requirements with minimal risk of deficiency and toxicity. Risk-benefit analysis requires data on habitual dietary intakes, an estimate of variation and effects of deficiency and excess on health. For some nutrients, the range between the upper and lower limits may be extremely narrow and even overlap, which creates difficulties when setting safety margins. A new approach for estimating optimal intakes, taking into account several health biomarkers, has been developed and applied to selenium, but at present there are insufficient data to extend this technique to other micronutrients. The existing methods for deriving reference values for Cu and Fe are described. For Cu, there are no sensitive biomarkers of status or health relating to marginal deficiency or toxicity, despite the well-characterised genetic disorders of Menkes and Wilson's disease which, if untreated, lead to lethal deficiency and overload, respectively. For Fe, the wide variation in bioavailability confounds the relationship between intake and status and complicates risk-benefit analysis. As with Cu, health effects associated with deficiency or toxicity are not easy to quantify, therefore status is the most accessible variable for risk-benefit analysis. Serum ferritin reflects Fe stores but is affected by infection/inflammation, and therefore additional biomarkers are generally employed to measure and assess Fe status. Characterising the relationship between health and dietary intake is problematic for both these trace elements due to the confounding effects of bioavailability, inadequate biomarkers of status and a lack of sensitive and specific biomarkers for health outcomes.

Pedo-geochemical baseline content levels and soil quality reference values of trace elements in soils from the Mediterranean (Castilla La Mancha, Spain)

AbstractTo evaluate trace element soil contamination, geochemical baseline contents and reference values need to be established. Pedo-geochemical baseline levels of trace elements in 72 soil samples of 24 soil profiles from the Mediterranean, Castilla La Mancha, are assessed and soil quality reference values are calculated. Reference value contents (in mg kg−1) were: Sc 50.8; V 123.2; Cr 113.4; Co 20.8; Ni 42.6; Cu 27.0; Zn 86.5; Ga 26.7; Ge 1.3; As 16.7; Se 1.4; Br 20.1; Rb 234.7; Sr 1868.4; Y 38.3; Zr 413.1; Nb 18.7; Mo 2.0; Ag 7.8; Cd 4.4; Sn 8.7; Sb 5.7; I 25.4; Cs 14.2; Ba 1049.3; La 348.4; Ce 97.9; Nd 40.1; Sm 10.7; Yb 4.2; Hf 10.0; Ta 4.0; W 5.5; Tl 2.3; Pb 44.2; Bi 2.2; Th 21.6; U 10.3. The contents obtained for some elements are below or close to the detection limit: Co, Ge, Se, Mo, Ag, Cd, Sb, Yb, Hf, Ta, W, Tl and Bi. The element content ranges (the maximum value minus the minimum value) are: Sc 55.0, V 196.0, Cr 346.0, Co 64.4, Ni 188.7, Cu 49.5, Zn 102.3, Ga 28.7, Ge 1.5, As 26.4, Se 0.9, Br 33.0 Rb 432.7, Sr 3372.6, Y 39.8, Zr 523.2, Nb 59.7, Mo 3.9, Ag 10.1, Cd 1.8, Sn 75.2, Sb 9.9, I 68.0, Cs 17.6, Ba 1394.9, La 51.3, Ce 93.5, Nd 52.5, Sm 11.2, Yb 4.2, Hf 11.3, Ta 6.3, W 5.2, Tl 2.1, Pb 96.4, Bi 3.0, Th 24.4, U 16.4 (in mg kg−1). The spatial distribution of the elements was affected mainly by the nature of the bedrock and by pedological processes. The upper limit of expected background variation for each trace element in the soil is documented, as is its range as a criterion for evaluating which sites may require decontamination.

Reference concentrations for trace elements in urine for the Brazilian population based on q-ICP-MS with a simple dilute-and-shoot procedure

Biomonitoring of trace elements is of critical importance in human health assessment. However, trace element concentrations in biological fluids are affected by environmental and physiological parameters, and therefore considerable variations can occur between specific population subgroups. Brazil is a large country with large environmental diversity and with a limited knowledge of the reference values (baseline data) for trace elements in biological fluids. Atomic absorption spectrometry (AAS) and inductively coupled plasma emission spectrometry (ICP-OES) are still the dominant analytical techniques used for biomonitoring trace element analysis in clinical specimens. However, the use of ICP-MS is becoming more usual in clinical laboratory analysis. Then, we evaluated here a simple dilute-and-shoot method for sequential determination of Al, Ba, Be, Cd, Co, Cu, Cs, Mn, Ni, Pb, Pt, Sb, Se, Sn, Tl and U in urine by quadrupole inductively coupled plasma mass spectrometry (q-ICP-MS). Urine samples (500 µL) were accurately pipetted into conical tubes (15 mL) and diluted to 10 mL with a solution containing 0.5 % (v/v) HNO3 + 0.005% (v/v) Triton X-100. Diluted urine samples also contain rhodium, iridium and yttrium added as internal standards. After that, samples were directly analyzed by ICP-MS against matrix-matching calibration. Method detection limit (3s, n = 20) were in the ng L-1 range for all analytes. The method was applied to the analysis of 412 ordinary urine samples from Brazilian healthy and non-exposed subjects to establish reference values. Data validation was provided by the analysis of the standard reference material (SRM) 2670a toxic elements in urine (freeze-dried) (high and low levels) from the National Institute of Standards and Technology (NIST) and reference urine samples from the trace elements intercomparison program operated by the Institut National de Sante' Publique du Quebec, Canada.

Trace element reference values in tissues from inhabitants of the EU. XII. Development of BioReVa program for statistical treatment

Statistical data treatment is a key point in the assessment of trace element reference values being the conclusive stage of a comprehensive and organized evaluation process of metal concentration in human body fluids. The EURO TERVIHT project (Trace Elements Reference Values in Human Tissues) was started for evaluating, checking and suggesting harmonized procedures for the establishment of trace element reference intervals in body fluids and tissues. Unfortunately, different statistical approaches are being used in this research field making data comparison difficult and in some cases impossible. Although international organizations such as International Federation of Clinical Chemistry (IFCC) or International Union of Pure and Applied Chemistry (IUPAC) have issued recommended guidelines for reference values assessment, including the statistical data treatment, a unique format and a standardized data layout is still missing. The aim of the present study is to present a software (BioReVa) running under Microsoft ® Windows platform suitable for calculating the reference intervals of trace elements in body matrices. The main scope for creating an ease-of-use application was to control the data distribution, to establish the reference intervals according to the accepted recommendation, on the base of the simple statistic, to get a standard presentation of experimental data and to have an application to which further need could be integrated in future. BioReVa calculates the IFCC reference intervals as well as the coverage intervals recommended by IUPAC as a supplement to the IFCC intervals. Examples of reference values and reference intervals calculated with BioReVa software concern Pb and Se in blood; Cd, In and Cr in urine, Hg and Mo in hair of different general European populations.

Human placenta as a ‘dual’ biomarker for monitoring fetal and maternal environment with special reference to potentially toxic trace elements.: Part 2: Essential minor, trace and other (non-essential) elements in human placenta

A survey of elemental composition of the human placenta was undertaken to evaluate reference values for minor and trace elements (essential and non-essential). The new data collection was narrowed down to results generated between the period of 1975–2000, since analytical methodology was becoming increasingly reliable with time for many elements. The search revealed the following results (μg/g, based on wet weight): Ca=770; Cl=1900; K=1685; Mg=100; Na=360; P=1700; and S=350. However, Na, P and S need further confirmation. For a group of essential trace elements following average values were evaluated (μg/g, based on wet weight): Co=0.007; Cr=0.03; Cu=0.9; Fe=69; I=0.005; Mn=0.08; Mo=0.02; Se=0.2; and Zn=10. However, the iodine value needs further confirmation. In addition, information values have been identified for a number of so-called non-essential elements such as Ag, Au, B, Ba, Br, Cs, F, La, Rb, Sb, Sc, Si, Sn, Sr, Ti, V and W. The survey results for toxic trace elements As, Cd, Hg, Ni and Pb are discussed in part 3 of this paper along with placenta as a biomonitor for toxic trace elements.

Reference values for trace and ultratrace elements in human serum determined by double-focusing ICP-MS.

Reference values for trace and ultratrace elements concentrations in healthy human serum, measured by double-focusing inductively coupled plasma-mass spectrometry (ICP-MS), are presented. Blood donors from Asturias (Spain) were selected as the reference population (n=59). Blood samples were collected, after donation, taking the necessary precautions to avoid contamination. All subjects analyzed had normal renal function and nutritional status, as shown from their creatinine and albumin levels. A total number of 14 elements (Al, Ca, Cr, Mn, Fe, Co, Cu, Zn, Rb, Sr, Mo, Cd, Pb, and U) were monitored almost simultaneously. Serum samples were diluted 1+4 with ultrapure water and matrix interferences were corrected using Sc, Ga, Y, and Tl as internal standards. Fe, Cu, and Zn were also determined by isotope dilution analysis (IDA). Reference trace element concentrations intervals observed containing 95% of the reference distribution after excluding outliers are presented. Fourteen serum samples from hemodialysis patients were also analyzed for comparison. High levels of Al, Cr, Sr, Mo, Mn, Pb, U, Co, and Cu and low levels of Fe, Zn, and Rb were found in the serum samples from hemodialysis patients compared to the corresponding reference values observed in this work.