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.     

Trace element status of hemodialyzed patients

The trace elements Ba, Bi, Cd, Co, Cs, Cu, Hg, La, Mn, Mo, Pb, Rb, Sb, Sn, Sr, Tl, and Zn were determined by inductively coupled plasma mass spectrometry in plasma samples of 68 hemodialysis patients. The same elements (with exception of La and Mn) were also determined in whole blood after mineralization with high-purity nitric acid/hydrogen peroxide in a closed-pressurized microwave system. The accuracy and precision was checked by analyzing two Seronorm “whole blood” reference materials. All samples were contaminated with barium (heparinized tubes) and the plasma samples with tin (collection tubes). The concentrations for Bi, Hg, Pb, Rb, Sb, and Sr in whole blood were within the literature ranges for healthy adults. All of the concentrations for Co, and some of the concentrations for Cd, Cs, Tl, and Zn were higher than the high limits of the normal ranges. Approximately 14% of the Cu concentrations were lower than the low limit of the normal range. The Mo and Sn concentrations are difficult to evaluate, because the normal ranges appears to be unreliable. All concentrations for Cd, Co, Mo, Pb, Sn, and Sr and some of the concentrations for Cu (15%) and Mn (75%) in the plasma samples were higher than the high limits of the normal ranges. The concentrations for Rb tended to be lower than the normal range. To establish unequivocally the causes for elevated and reduced concentrations of trace elements in whole blood and plasma of dialysis patients, all fluids in the dialysis process must be investigated.     

Circulating beta-chemokines and matrix metalloproteinase-9/tissue inhibitor of metalloproteinase-1 system in hemodialyzed patients--role of oxidative stress

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), beta-chemokines, increased oxidative stress (SOX) and inflammation have been implicated as important factors in atherosclerosis and vascular remodeling. We hypothesized the possible roles of beta-chemokines [monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory proteins (MIP-1alpha, MIP-1beta) and regulated upon activation, normal T-cell expressed and secreted (RANTES)] as regulators of the metabolism of the vascular extracellular matrix in conditions of increased SOX in hemodialysis (HD) patients. We compared pre-dialysis levels of MMP-9/TIMP-1 system, beta-chemokines, Cu/Zn superoxide dismutase (Cu/Zn SOD) as a marker of SOX and C-reactive protein (CRP) as a marker of inflammation in HD patients with and without cardiovascular disease (CVD) to those of controls. HD patients, particularly those with CVD, showed a significant increase in values of Cu/Zn SOD, CRP, TIMP-1, TIMP-1/MMP-9 ratio, MCP-1 and MIP-1beta, whereas RANTES levels were lower than in the controls. The levels of MIP-1alpha as well as MMP-9 in all HD groups were similar to the controls. The positive correlations were observed between the MMP-9/TIMP-1 system and beta-chemokines, SOX and inflammation in whole HD group and in the subgroup with CVD. Multivariate analysis showed that the duration of dialysis followed by Cu/Zn SOD, MIP-1alpha and beta levels were the significant positive predictors of TIMP-1. In conclusion, our data show that MMP-9/TIMP-1 system and beta-chemokines could cooperate in conditions of elevated SOX, which ultimately predisposes hemodialysis patients to accelerated atherosclerosis.     

Trace elements and lipid peroxidation in uremic patients on hemodialysis

Trace elements and lipid peroxidation in 26 patients with chronic renal failure treated with hemodialysis and 25 healthy subjects were observed. Both plasma and erythrocyte trace elements and plasma malon dialdehyde (MDA) were examined immediately before and after hemodialysis. Increased levels of plasma Cu, MDA, and erythrocyte Pb, Mn, Zn, and a significantly decreased plasma Se, Zn and erythrocyte Se were found in patients before hemodialysis. After a single hemodialysis, erythrocyte Mn, Cu, Zn, and plasma Cu, Al, and MDA were significantly increased whereas both plasma and erythrocyte Se were lower in patients than in healthy subjects. The level of MDA was not significantly changed during the single hemodialysis. Both plasma and erythrocyte Zn levels and plasma Cu and Al were significantly higher after hemodialysis than before hemodialysis. In conclusion, levels of trace elements are altered by hemodialysis, which may increase patient susceptibility to lipid peroxidation in uremia.     

Elements in Lung Tissues of Patients from a High Lung Cancer Incidence Area of China

The concentrations of trace elements are closely related to tumor genesis, progression, and therapy. In order to establish the extent to which trace elements apply to lung cancer, 15 trace elements were determined in 60 lung tissue samples from residents of Xuanwei and Fuyuan, two counties with extremely high lung cancer incidences in Yunnan province, China. The results indicated that the levels of V, Fe, Zn, Cd, Ni, Cu, Se, and Pb in the lung cancer tissues were significantly different from those in benign tissues. Among the eight elements, the levels of V, Fe, Zn, and Cd in the lung cancer tissues were lower than those in the benign tissues, while those of Ni, Cu, Se, and Pb were higher. Multiple conditional logistic regression showed that among the 15 elements, Cu, Pb (β > 0, OR > 1), and Zn (β < 0, OR < 1) were closely related to the lung cancer. Cu and Pb were classified as risk factors for local lung cancer and Zn was identified as a protective factor. The results obtained will provide dietary suggestions in terms of how to reduce lung cancer risks by appropriately balancing the intakes of certain trace elements especially for individuals who are from those two counties.     

The distribution of Cd, Cu, Pb and Zn in the biota of two freshwater sites with different trace metal inputs

The concentrations of Cd, Cu, Pb, and Zn were determined in the abiotic and biotic components at two sites in the Fox River, Illinois. Analysis of the metals was completed on solutions of wet ashed or dry ashed samples with a single beam atomic absorption spectrophotometer. Despite different inputs of the trace metals there were no significant differences in the concentration of Cu or Zn in the biota between the two sites. This was postulated to be due to physiological control of these metals. However, Cd and Pb concentrations were higher in the biota and substrate at the high input site. No accumulation of Cd or Pb occurred at higher trophic levels. Cu and Zn concentrations were similar for all biota with the exception of crayfish and snails which had higher Cu and Zn concentrations, respectively.     

Serum Levels of Trace Elements and Heavy Metals in Patients with Acute Hemorrhagic Stroke

Trace elements are essential components of biological structures, but alternatively, they can be toxic at concentrations beyond those necessary for their biological functions. Changes in the concentration of essential trace elements and heavy metals may affect acute hemorrhagic stroke. The aim of this study was to measure serum levels of essential trace elements [iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), and magnesium (Mg)] and heavy metals [cobalt (Co), cadmium (Cd), and lead (Pb)] in patients with acute hemorrhagic stroke. Twenty-six patients with acute hemorrhagic stroke and 29 healthy controls were enrolled. Atomic absorption spectrophotometry (UNICAM-929) was used to measure serum Fe, Cu, Pb, Cd, Zn, Co, Mn and Mg concentrations. Serum Cd, Pb and Fe levels were significantly higher in patients with acute hemorrhagic stroke than controls (p < 0.001), while serum Cu, Zn, Mg and Mn levels were significantly lower (all p < 0.001). However, there was no significant difference between the groups with respect to serum Co levels (p > 0.05). We first demonstrate increased Cd, Pb, and Fe levels; and decreased Cu, Zn, Mg, and Mn levels in patients with acute hemorrhagic stroke. These findings may have diagnostic and prognostic value for acute hemorrhagic stroke. Further studies are required to elucidate the roles of trace elements and heavy metals in patients with acute hemorrhagic stroke.     

Screening of Trace Metals in the Plasma of Breast Cancer Patients in Comparison with a Healthy Population

The plasmas of breast cancer patients and healthy donors were analyzed for selected trace metals by a flame atomic absorption spectrophotometric method. In the plasma of breast cancer patients, mean concentrations of macronutrients/essential metals, Na, K, Ca, Mg, Fe, and Zn were 3584, 197.0, 30.80, 6.740, 5.266, and 6.170 ppm, respectively, while the mean metal levels in the plasma of healthy donors were 3908, 151.0, 72.40, 17.70, 6.613, and 2.461 ppm, respectively. Average concentrations of Cd, Cr, Cu, Mn, Ni, Pb, Sb, Sr, and Zn were noted to be significantly higher in the plasma of breast cancer patients compared with healthy donors. Very strong mutual correlations (r > 0.70) in the plasma of breast cancer patients were observed between Cd–Pb, Cr–Li, Li–K, Li–Cd, K–Cr, Li–Pb, Cr–Co, Cu–Ni, Co–K, Cd–K, and K–Pb, whereas, Al–Cr, Ca–Zn, Cd–Sb, Cd–Zn, Ca–Mg, Fe–Zn, and Na–Mn exhibited strong relationships (r > 0.60) in the plasma of healthy donors. The cluster analysis revealed considerably different apportionment of trace metals in the two groups of donors. The average metal concentrations of different age groups of the two donor categories were also evaluated, which showed the build-up of Al, Cd, Co, Cr, Mn, Li, Pb, Sb, and Zn in the plasma of breast cancer patients. The role of some trace metals in carcinogenesis is also discussed. The study indicated appreciably different patterns of metal distribution and correlation in the plasma of breast cancer patients in comparison with the healthy population.     

青岛地区2010 年2044 例儿童微量元素测量结果分析

目的:了解青岛地区2010年儿童体内微量元素水平。方法:随机抽样2010年来我院健康查体的2044例儿童,分别测量末梢血Cu、Zu、Ca、Mg、Fe、Pb、Cd 7种元素水平,将结果按年龄分组进行统计分析。结果:各年龄段儿童均无Cu、Mg两种元素的缺乏和Cd元素的超标;Zn、Ca、Fe三种元素在不同年龄段儿童中均有不同程度缺乏,且含量及缺乏率的差异在不同年龄段均有统计学意义(P<0.05);Pb仅有22个超标。结论:微量元素整体水平不容乐观,并且不同年龄段儿童中的含量水平及缺乏程度差异较大,了解这种年龄差异对指导不同时期儿童的保健工作有重要意义。     

高通量血液透析对糖尿病肾病血液透析患者心脏功能及结构的影响及预后的影响因素分析

摘要 目的：探讨高通量血液透析对糖尿病肾病（DN）血液透析患者心脏功能及结构的影响,并分析预后的影响因素。方法：选取2017年5月~2018年11月期间我院收治的DN血液透析患者（n=172）,上述DN血液透析患者中普通透析治疗者60例（普通透析组）、高通量血液透析治疗者112例（高通量透析组）。普通透析组采用低通量透析治疗,高通量透析组采用高通量透析治疗,比较两组患者心脏功能及结构以及预后情况,采用单因素、多因素Logistic回归分析预后的影响因素。结果：高通量透析组治疗6个月后左心房内径（LAD）、左心室舒张末内径（LVDd）、左心室心肌重量指数（LVMI）低于治疗前和普通透析组（P<0.05）,高通量透析组治疗6个月后左心室射血分数( LVEF )高于治疗前和普通透析组（P<0.05）。高通量透析组的生存率高于普通透析组（P<0.05）。存活组年龄、上机前舒张压、上机前收缩压、血磷、全段甲状旁腺激素（iPTH）均低于死亡组（P<0.05）,存活组透析频率、白蛋白、血红蛋白均高于死亡组（P<0.05）,两组性别、血钙比较无差异（P>0.05）。多因素Logistic回归分析结果显示,上机前舒张压高、上机前收缩压高、血磷高、iPTH高、透析频率少、白蛋白低、血红蛋白低均是DN血液透析患者死亡的危险因素（P<0.05）。结论：高通量血液透析能减轻DN患者血液透析所引起的心脏功能及结构损伤,改善患者预后。影响DN血液透析患者预后的因素较多,其中上机前舒张压、上机前收缩压、血磷、iPTH越高,白蛋白、血红蛋白越低,透析频率越少,患者的死亡风险越大。     

Comparative Assessment of Essential and Toxic Metals in the Blood of Rheumatoid Arthritis Patients and Healthy Subjects

The present study deals with the comparative evaluation of essential and toxic metals in rheumatoid arthritis and healthy donors. Blood samples collected from rheumatoid arthritis patients and healthy subjects were analysed for selected essential and toxic metals (Ca, Mg, Fe, Zn, Cu, Co, Mn, Cr, Cd and Pb). The samples were digested in nitric acid and perchloric acid mixture, followed by quantification of the metals using atomic absorption spectrometry. Mean levels of Ca, Mg, Fe and Zn were significantly higher in the blood of healthy donors; however, elevated levels of Cd, Co, Cr, Cu and Pb were observed in blood of the patients. The correlation coefficients among the selected metals in the blood of arthritis patients were significantly different compared with the healthy counterparts. Multivariate cluster analysis revealed mutual apportionment of the essential and toxic metals in blood of the patients, whereas, in controls, the essential and toxic metals revealed diverse apportionment. Variations in the metal levels with gender, residence and smoking habits were also evaluated in both donor groups. Relative distribution, correlation and apportionment of the essential and toxic metals in the blood of the patients were significantly different than of controls.     

Spatial distribution,contamination levels,sources, and potential health risk assessment of trace elements in street dusts of Urumqi city,NW China

Abstract

A total of 83 dust samples were collected from the streets of Urumqi city in NW China and analyzed for the concentrations of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn elements. The spatial distribution, contamination levels, main sources, and potential health risks of these trace elements were determined based on geostatistical analysis, geo-accumulation index, multivariate analysis, and the health risk assessment model introduced by the USEPA, respectively. The obtained results indicate that the average concentrations of Cd, Cr, Cu, Hg, Ni, Pb, and Zn exceed the corresponding background values determined in Xinjiang soils by factors of 2.0, 1.35, 1.38, 8.24, 1.28, 2.09, and 3.26, respectively. The spatial distribution patterns of the nine trace elements in street dust were found to be substantially heterogeneous, and the contamination level decreased in the following order: Hg?>?Zn?>?Pb?>?Cd?>?Cr?>?Cu?>?As?>?Ni?>?Mn. Based on the identified concentrations, the collected dust samples were found to be moderately polluted by Hg, and not polluted by As, Cr, Cu, Mn, and Ni. The remaining elements, Cd, Pb, and Zn lie on the borderline between non-pollution and moderate pollution levels. Furthermore, it was shown that Mn and Zn in street dusts originate from both, natural and anthropogenic sources, while As, Cd, Cr, Cu, Hg, Ni, and Pb are mainly produced by anthropogenic sources. Overall, the carcinogenic and non-carcinogenic health risks of the analyzed elements, instigated primarily by oral ingestion of street dusts, were found to be within the acceptable range for both, children and adults. As and Cr are the main non-carcinogenic elements, whereas Cr is the major carcinogenic element among the investigated dust-bound metals in the study area.     

Seasonal Variation of Metals in Seawater, Sediment, and Manila Clam Ruditapes philippinarum from China

Concentrations of trace metals (Cu, Pb, Zn, Cd, Cr, Hg, and As) were determined for the first time in seawater, sediment, and Manila clam from Deer Island, Liaoning Province, China. The seawater, sediment, and clam samples were collected seasonally at three clam farming sites around Deer Island during 2010–2011. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the seawater samples were 4.16, 0.72, 5.88, 0.45, 2.51, 0.03, and 1.02 μg/l, respectively. The seasonal variations of trace metals in seawater showed a significant difference in the concentrations of Cu, Pb, Zn, Hg, and As among seasons. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the sediment samples were 6.43, 13.80, 53.08, 1.10, 36.40, 0.05, and 4.78 mg/kg dry weight, respectively. Trace metal concentrations in sediment seasonally varied significantly except for Cd and Hg. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the clam samples were 11.28, 0.61, 92.50, 0.58, 3.98, 0.03, and 1.98 mg/kg dry weight, respectively. Concentrations of Cu, Zn, Cd, Cr, and As in Manila clam showed marked seasonal fluctuations with significant difference. Cu and Zn were the metals with the highest mean biosediment accumulation factor values in Manila clam. Besides, significant correlations for the concentrations of Cu and Zn relative to their concentrations in sediment were also found. Such differences in regression analyzes may be explained by differential bioaccumulation of essential and xenobiotic metals. Concentrations of trace metals in Manila clam did not exceed the maximum established regulatory concentrations for human consumption. Moreover, the calculations revealed that the estimated daily intake values for the examined clam samples were below the internationally accepted dietary guidelines and the calculated hazard quotient values were well less than 1, thus strongly indicating that health risk associated with the intake studied metals through the consumption of Manila clam from Deer Island was absent.     

Acute and chronic influence of hemodialysis according to the membrane used on phagocytic function of neutrophils and monocytes and pro-inflammatory cytokines production in chronic renal failure patients

This work evaluated the phagocytic capacity of monocytes and neutrophils, and tumor necrosis factor-alpha, interleukin 6, 1 and 8 serum levels in chronic renal failure patients under peritoneal dialysis and hemodialysis treatment, compared with chronic renal failure patients without dialysis treatment and healthy individuals, in order to contribute to a better understanding of the action of these therapies on the evolution of chronic renal failure patients. All patients with chronic renal failure (under dialysis or not) showed decreased phagocytic capacity of neutrophils and monocytes. All those in hemodialysis (cellulose acetate or polysulfone membranes) showed a decreased phagocytic capacity. The phagocytic index for neutrophil was 13 times lower than that of the control group for both membranes, whereas for monocytes, only those using polysulfone membrane showed a significant decrease of 4.9 times in phagocytic capacity. There was an acute stimulation of the phagocytosis by neutrophils after a single session of dialysis with both types of membrane, while only cellulose acetate membrane decreased the phagocytic index of monocytes after the hemodialysis session. Patients using cellulose acetate showed a chronic increase in tumor necrosis factor-alpha serum levels, while those using polysulfone showed a chronic increase in interleukin 6. After a single hemodialysis procedure, no acute effect of the treatment on tumor necrosis factor-alpha and interleukin 6 levels was identified. The decreased phagocytic function of neutrophils and monocytes may account for the high levels of susceptibility of chronic renal failure patients to infections with pyogenic bacteria and tuberculosis. Furthermore, inflammatory activity may occur with both types of membrane studied, suggesting that it will be useful for these patients to evaluate some anti-inflammatory or anti-cytokine therapies against tumor necrosis factor-alpha and interleukin 6, in order to avoid cardiovascular complication.     

Trace element imbalances in patients undergoing chronic hemodialysis therapy – Report of an observational study in a cohort of Portuguese patients

IntroductionPatients with end-stage renal disease undergoing hemodialysis therapy are at risk of developing deficiencies of essential trace elements and/or overload of toxic trace elements, both of which may significantly affect their clinical status of. Those imbalances may result from the disease itself but also from the quality of the therapeutic process, namely the hemodialysis process, which has greatly evolved in the last decades. Thus, old observations that have been assumed as very well-proven have been recently questioned. In this case-control study we evaluate the current trace elements status in a group of Portuguese patients under hemodialysis therapy.Material and methodsSerum samples from patients (n = 93), collected for the routine periodic control of Al levels, were analyzed for a wide panel of trace elements (Li, Al, Mn, Co, Ni, Cu, Zn, Se, Rb, Sr, Mo, Cd, Ba, Pb) using inductively coupled plasma mass spectrometry technique (hemodialysis patients’ group). For comparison purposes, samples of individuals with no evidence of renal disease according to standard laboratory analytical criteria (n = 50) were also analyzed (control group).ResultsThe results showed significant differences between the two groups, with higher values in hemodialysis patients group for Al (14.6 vs. 9.5 μg/L), Co, Ni, Sr, Mo (4.5 vs. 1.4 μg/L), Cd (0.058 vs. 0.025 μg/L) and Pb (0.55 vs. 0.30 μg/L); and lower values in hemodialysis patients group for Li (4.0 vs. 75.8 μg/L), Mn, Cu (943.5 vs. 1038.5 μg/L), Zn (943.5 vs. 1038.5 μg/L), Se (71.5 vs. 103.8 μg/L), Rb (202.4 vs. 300.3 μg/L) and Ba (0.65 vs. 8.7 μg/L).ConclusionThis study confirms that hemodialysis patients tend to present significant trace elements imbalances, which may be related to the higher morbidity and mortality observed in this specific patients’ group.     

Interactions between toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements in the tissues of cattle from NW Spain

Since the toxicity of one metal or metalloid can be dramatically modulated by the interaction with other toxic or essential metals, studies addressing the chemical interactions between trace elements are increasingly important. In this study correlations between the main toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements were evaluated in the tissues (liver, kidney and muscle) of 120 cattle from NW Spain, using Spearman rank correlation analysis based on analytical data obtained by ICP-AES. Although accumulation of toxic elements in cattle in this study is very low and trace essential metals are generally within the adequate ranges, there were significant associations between toxic and essential metals. Cd was positively correlated with most of the essential metals in the kidney, and with Ca, Co and Zn in the liver. Pb was significantly correlated with Co and Cu in the liver. A large number of significant associations between essential metals were found in the different tissues, these correlations being very strong between Ca, Cu, Fe, Mn, Mo and Zn in the kidney. Co was moderately correlated with most of the essential metals in the liver. In general, interactions between trace elements in this study were similar to those found in polluted areas or in experimental studies in animals receiving diets containing high levels of toxic metals or inadequate levels of nutritional essential elements. These interactions probably indicate that mineral balance in the body is regulated by important homeostatic mechanisms in which toxic elements compete with the essential metals, even at low levels of metal exposure. The knowledge of these correlations may be essential to understand the kinetic interactions of metals and their implications in the trace metal metabolism.     

Fingernails as biological indices of metal exposure

Metal determination in human tissues is the most common application of biological monitoring for screening, diagnosis and assessment of metal exposures and their risks. Various biopsy-materials may be used. This paper deals with the quantitative determination of Cd, Pb, Cr, Mn, Fe, Ni, Cu, and Zn concentrations in nails of male subjects exposed to these metals alongwith their respective controls, while working in locomotive, carriage and roadways workshops, and lead battery factories. The levels of Cd, Pb, Cr, Mn, Fe, Ni, Cu and Zn in fingernails, assayed by atomic absorption spectrophotometry, were compared with their respective controls by student ‘t’ test. All the obtained values were correlated to the personal and medical history of the subjects under study. Significantly high levels of Cd, Pb, Cr, Fe, Ni, Cu and Zn were present in smokers, compared to nonsmokers. The concentrations of Cd, Pb, Cr, Mn and Fe were not significantly high in vegetarian subjects. It was also observed that there is no contribution of liquor towards nail-metal concentration. Significant correlations were observed between skin disease and Cr, Mn, Fe, Cu; hypertension and Cd, Mn, Cu; mental stress and Cd, Pb, Mn, Ni, Cu, Zn; diabetes and Cr, Mn, Ni; chest pain and Pb; respiratory trouble and Cr, Mn, Fe, Ni, Zn; tuberculosis and Zn; acidity and Cd; and ophthalmic problems and Mn, Fe, Ni, and Zn     

Cord Blood Levels of Toxic and Essential Trace Elements and Their Determinants in the Terai Region of Nepal: A Birth Cohort Study

The purpose of this study is to evaluate the cord blood level of toxic and trace elements and to identify their determinants in Terai, Nepal. One hundred pregnant women were recruited from one hospital in Chitwan, Nepal in 2008. The cord blood levels of toxic [lead (Pb), arsenic (As), and cadmium (Cd)], essential trace elements [zinc (Zn), selenium (Se), and copper (Cu)], demographic, socioeconomic, and behavioral variables were measured. The mean values of Pb, As, Cd, Zn, Se, and Cu in cord blood level were found as 31.7, 1.46, 0.39, 2,286, 175, and 667 μg/L, respectively. In the multivariate regression model, cord blood As levels from less educated mothers were higher than those from educated mothers (coefficient = -0.01, 95% confidence interval [CI] = -0.02-0.00). The maternal age was positively associated with the cord blood Cd level (coefficient = 0.02, 95% CI = 0.01-0.03), while it was negatively associated with the cord blood As level (coefficient = -0.01, 95% CI = -0.03--0.01). Cord blood levels of Pb, Zn, Se, and Cu were not associated with maternal age, socioeconomic status, living environment, and smoking status. As and Cd levels were relatively lower than those reported in previous studies in Asia, while the levels of Pb and the trace elements were similar. Less educated mothers are more likely to become a higher in utero As source to their fetus, and fetuses of older mothers were more likely to have higher in utero Cd exposure in Terai, Nepal.     

Evaluation of trace element status of organic dairy cattle

The present study aimed to evaluate trace mineral status of organic dairy herds in northern Spain and the sources of minerals in different types of feed. Blood samples from organic and conventional dairy cattle and feed samples from the respective farms were analysed by inductively coupled plasma mass spectrometry to determine the concentrations of the essential trace elements (cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), iodine (I), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se) and zinc (Zn)) and toxic trace elements (arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb)). Overall, no differences between organic and conventional farms were detected in serum concentrations of essential and toxic trace elements (except for higher concentrations of Cd on the organic farms), although a high level of inter-farm variation was detected in the organic systems, indicating that organic production greatly depends on the specific local conditions. The dietary concentrations of the essential trace elements I, Cu, Se and Zn were significantly higher in the conventional than in the organic systems, which can be attributed to the high concentration of these minerals in the concentrate feed. No differences in the concentrations of trace minerals were found in the other types of feed. Multivariate chemometric analysis was conducted to determine the contribution of different feed sources to the trace element status of the cattle. Concentrate samples were mainly associated with Co, Cu, I, Se and Zn (i.e. with the elements supplemented in this type of feed). However, pasture and grass silage were associated with soil-derived elements (As, Cr, Fe and Pb) which cattle may thus ingest during grazing.     

Maternal and neonatal scalp hair concentrations of zinc, copper, cadmium, and lead: relationship to some lifestyle factors

Postpartum scalp hair samples from 82 term-pregnancy mother/ neonate pairs were analyzed for their concentrations of zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb), using inductively coupled plasma-mass spectrometry. Maternal and neonatal Zn concentrations had geometric means (and 99% confidence intervals) of 122.5 microg/g (117.9--131.5 microg/g) and 146.9 microg (141.5--156.7 microg/g) respectively. Corresponding Cu values were 18.4 microg/g (17.6--23.8 microg/g) and 6.7 microg/g (6.3--7.6 microg/g). Those of Cd were 0.49 microg/g (0.47--0.69 microg/g) in the mothers and 0.57 microg/g (0.55--0.86 microg/g) in the neonates. For Pb, they were 7.95 microg/g (7.60--9.32 microg/g) and 4.56 microg/g (4.39--5.56 microg/g). Cigarette smoking, despite its relatively low prevalence (19.5%), was associated with lower Zn and higher Cd and Pb concentrations and in lower Zn/Cd and Zn/Pb molar concentration ratios. Smoking also altered interelemental relationships, particularly those of Zn with Cd and Pb and those between Cd and Pb. Smoking frequency appeared to show negative dose-response effects on maternal and neonatal Zn concentrations, Zn/Pb molar concentration ratios, and birth weight. Mothers with a history of oral contraceptive (OC) usage had significantly higher Cu concentrations and lower Zn/Cu molar concentration ratios than non users, with the highest Cu concentrations and lowest Zn/Cu values being associated with third-generation OCs. No similar effects were elicited in the respective neonatal Cu concentrations. Neither alcohol consumption nor prenatal supplementation with iron and/or folic acid had discernible effects on the maternal or neonatal elemental concentrations. The data from this study suggest that in a given population of term-pregnancy mothers and neonates, significant interindividual variations in hair trace element concentrations can occur, irrespective of commonality of general environment, and that lifestyle factors, including cigarette smoking and OC usage history, can be significant contributory factors to such variations. The data are discussed in relation to the effects of smoking-associated exposure to Cd and Pb exposure on Zn availability for placental transfer, as well as on the quantitative maternal Zn supply levels to the fetus resulting from the known tendency of smokers to have lower dietary intakes of Zn.