Association of Urinary Metals With Cardiovascular Disease Incidence and All-Cause Mortality in the Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: Exposure to metals has been associated with cardiovascular disease (CVD) end points and mortality, yet prospective evidence is limited beyond arsenic, cadmium, and lead. In this study, we assessed the prospective association of urinary metals with incident CVD and all-cause mortality in a racially diverse population of US adults from MESA (the Multi-Ethnic Study of Atherosclerosis). METHODS: We included 6599 participants (mean [SD] age, 62.1 [10.2] years; 53% female) with urinary metals available at baseline (2000 to 2001) and followed through December 2019. We used Cox proportional hazards models to estimate the adjusted hazard ratio and 95% CI of CVD and all-cause mortality by baseline urinary levels of cadmium, tungsten, and uranium (nonessential metals), and cobalt, copper, and zinc (essential metals). The joint association of the 6 metals as a mixture and the corresponding 10-year survival probability was calculated using Cox Elastic-Net. RESULTS: During follow-up, 1162 participants developed CVD, and 1844 participants died. In models adjusted by behavioral and clinical indicators, the hazard ratios (95% CI) for incident CVD and all-cause mortality comparing the highest with the lowest quartile were, respectively: 1.25 (1.03, 1.53) and 1.68 (1.43, 1.96) for cadmium; 1.20 (1.01, 1.42) and 1.16 (1.01, 1.33) for tungsten; 1.32 (1.08, 1.62) and 1.32 (1.12, 1.56) for uranium; 1.24 (1.03, 1.48) and 1.37 (1.19, 1.58) for cobalt; 1.42 (1.18, 1.70) and 1.50 (1.29, 1.74) for copper; and 1.21 (1.01, 1.45) and 1.38 (1.20, 1.59) for zinc. A positive linear dose-response was identified for cadmium and copper with both end points. The adjusted hazard ratios (95% CI) for an interquartile range (IQR) increase in the mixture of these 6 urinary metals and the corresponding 10-year survival probability difference (95% CI) were 1.29 (1.11, 1.56) and -1.1% (-2.0, -0.05) for incident CVD and 1.66 (1.47, 1.91) and -2.0% (-2.6, -1.5) for all-cause mortality. CONCLUSIONS: This epidemiological study in US adults indicates that urinary metal levels are associated with increased CVD risk and mortality. These findings can inform the development of novel preventive strategies to improve cardiovascular health.

The association between the essential metal mixture and fasting plasma glucose in Chinese community-dwelling elderly people.

BACKGROUND: Epidemiological studies about the effect of essential metal mixture on fasting plasma glucose (FPG) levels among elderly people are sparse. The object of this study was to examine the associations of single essential metals and essential metal mixture with FPG levels in Chinese community-dwelling elderly people. METHODS: The study recruited 2348 community-dwelling elderly people in total. Inductively coupled plasma-mass spectrometry was adopted to detect the levels of vanadium (V), selenium (Se), magnesium (Mg), cobalt (Co), calcium (Ca), and molybdenum (Mo) in urine. The relationships between single essential metals and essential metal mixture and FPG levels were evaluated by linear regression and Bayesian kernel machine regression (BKMR) models, respectively. RESULTS: In multiple-metal linear regression models, urine V and Mg were negatively related to the FPG levels (ß = - 0.016, 95 % CI: - 0.030 to - 0.003 for V; ß = - 0.021, 95 % CI: - 0.033 to - 0.009 for Mg), and urine Se was positively related to the FPG levels (ß = 0.024, 95 % CI: 0.014-0.034). In BKMR model, the significant relationships of Se and Mg with the FPG levels were also found. The essential metal mixture was negatively associated with FPG levels in a dose-response pattern, and Mg had the maximum posterior inclusion probability (PIP) value (PIP = 1.0000), followed by Se (PIP = 0.9968). Besides, Co showed a significant association with decreased FPG levels in older adults without hyperlipemia and in women. CONCLUSIONS: Both Mg and Se were associated with FPG levels, individually and as a mixture. The essential metal mixture displayed a linear dose-response relationship with reduced FPG levels, with Mg having the largest contribution to FPG levels, followed by Se. Further prospective investigations are necessary to validate these exploratory findings.

Occupational low-level exposure to hard metals: cobalt and tungsten biomonitoring as an effective tool to evaluate the effectiveness of industrial hygiene interventions for risk management.

Purpose: The aim of the study was to assess the exposure to Cobalt (Co) and Tungsten (W) in a group of hard metal tool sharpeners through a combined approach of air and biological monitoring, and to evaluate the effectiveness of a control and improvement intervention carried out in collaboration with the medical officers of the local Health Protection Agency, by biomonitoring.Methods: We enrolled 132 workers from 17 companies of the province of Brescia, northern Italy. The study was performed in two phases: (1) an environmental and biomonitoring survey to assess the workers' exposure to Co and W at their usual working conditions; (2) a further biomonitoring survey 3 months after the enforcement of a control and improvement intervention, to assess its effectiveness.Results: Workers were found to be exposed to low concentration of airborne dust containing Co and W but after the intervention we recorded a significant decrease of the urinary concentrations of both Co and W. The extent of the decrease was correlated to the number of preventive industrial hygiene interventions that were carried out.Conclusions: Biological monitoring of Co and W in the hard metal tools manufacturing industry is a sensitive and effective method to evaluate the effectiveness of prevention practices.

Urinary cobalt and ferritin in four-years-old children.

Cobalt (Co) is an essential trace element but may cause toxic effects upon occupational or environmental exposure. The present study is aimed to determine the urine concentrations of Co in four years-old children in the INMA-Asturias cohort (Spain) and to assess the factors determining the observed levels. This cohort is located in a heavily industrialized zone with strong potential for metal exposure. Some diet components such as consumption of sweets were meaningfully associated with higher urine Co concentrations. Traffic pollution also showed a noteworthy positive association with Co levels. Family tobacco consumption did not show substantial association with the urine concentrations of this metal in the INMA-Asturias children. A significant inverse association between urine Co and venous blood ferritin was found. Iron deficiency anemic children had significantly higher concentrations of Co than those with normal levels, e.g. median values 1.9 µg/g creatinine and 1.0 µg/g creatinine, respectively. This association could be explained by an increased expression of DMT1, a divalent metal transporter that captures higher levels of iron in deficiency states of this metal. This transporter is non-specific and not only captures iron but also other divalent metals such as Co. The presence of this metal in iron deficiency anemic children may represent an additional disturbing health factor that must be considered during treatment.

A monolithic copolymer prepared from N-(4-vinyl)-benzyl iminodiacetic acid, divinylbenzene and N,N'-methylene bisacrylamide for preconcentration of cadmium(II) and cobalt(II) from biological samples prior to their determination by ICP-MS.

A capillary monolith consisting of poly[N-(4-vinyl)-benzyl iminodiacetic acid-co-divinylbenzene-co-N,N'-methylene bisacrylamide), referred to as poly(VBIDA-DVB-Bis), has been prepared. It is shown to be an efficient sorbent for the enrichment of Co(II) and Cd(II). The two ions are completely retained by the monolith in the pH range from 4.0 to 9.0. The breakthrough curve tests were adopted to evaluate the adsorption performance of the monolith towards Co(II) and Cd(II). A dose-response model was used to describe the breakthrough curves of the two ions at different initial concentrations. The adsorption capacities for Co(II) and Cd(II) are 1.54 and 1.73 mg·m-1 at a concentration level of 2.5 mg·L-1, respectively. The enrichment factor is 100, and the required sample volume is 5 mL. Following elution of the two ions with 0.5 M HNO3, they were quantified by ICP-MS. The limits of detection in a 1 mL sample are 0.35 ng·L-1 for Co(II) and 0.44 ng·L-1 for Cd(II). The method was applied to the determination of Co(II) and Cd(II) in spiked rice, human urine and seawater samples. Graphical abstract Schematic representation of a monolithic copolymer prepared from N-(4-vinyl)-benzyl iminodiacetic acid (VBIDA), divinylbenzene (DVB) and N,N'-methylene bisacrylamide (Bis) and its application for selective capturing of cadmium(II) and cobalt(II) from complex sample matrices prior to their determination by ICP-MS.

Neglected exposure route: cobalt on skin and its associations with urinary cobalt levels.

OBJECTIVES: Cobalt (Co) exposure is associated with adverse health effects including skin sensitisation, asthma and interstitial lung fibrosis. Exposure to Co in industrial settings is often assessed using air samples or biomonitoring in urine. Skin exposure is rarely measured. Aim of this study was to quantify and compare the importance of Co skin exposure and respiratory exposure in determining urinary Co concentrations. METHODS: Co skin exposure was measured in 76 hard metal workers by acid wipe sampling before and at the end of work shifts. Spot urine was collected during a 24-hour period from the start of a shift. Respiratory exposure was measured by personal inhalable dust sampling during a shift in 30 workers. Co was analysed by inductively coupled plasma mass spectrometry. RESULTS: Quantile regression modelling showed that a doubling of Co on skin before or at the end of shift increased the median urinary concentration of Co by 70% (p<0.001) or 32% (p<0.001), respectively. A doubling of Co in air increased median urinary Co by 38% (p<0.001). Co skin exposures were still significantly associated with urinary Co after excluding a group of workers with high respiratory exposure (33%, p=0.021 and 17%, p=0.002). CONCLUSIONS: The results indicate an association between Co skin exposure and urinary Co concentrations. This should be considered when using urinary Co as a biomarker of exposure.

Potential presence of metals in patients treated with metal-metal coupling prostheses for hip arthroplasty at 7 and 10 years of follow-up.

BACKGROUND: Beginning in 2008, metal-on-metal prostheses have been in the spotlight owing to much higher revision rates than expected. Adverse local tissue reactions have been well described in the literature as potential complications. METHODS: Between 2012 and 2013, 13 patients with metal-on-metal total hip replacements were evaluated clinically and radiologically and with laboratory samples. The same tests were repeated between 2015 and 2016 on eight patients to assess any changes. In the laboratory assessment, we searched for chromium, cobalt, molybdenum, and nickel in blood and urine samples over 24 h. RESULTS: Clinical assessment has shown good score in all patients except one. On a second examination, between 2015 and 2016, all patients obtained results similar to those obtained in the first assessment, except a patient, who reported a recent fall. In the radiological assessment between 2012 and 2013, results were optimal, apart from a case of aseptic mobilization. The patients reassessed 3 years after the first examination showed radiological results similar to those previously obtained, apart from a patient, who showed signals of mobilization. Metal levels found in their blood decreased in most cases after 3 years. Urine levels of nickel increased in five subjects, and chromium levels increased in four, but levels of cobalt and molybdenum decreased in four patients. CONCLUSION: It could be hypothesized that the decreasing trend of metal ion levels is associated with a stable wear status. On the contrary, a progressive increase in metal ion levels must be considered as early proof of implant loosening.

Biological monitoring of cobalt in hard metal factory workers.

PURPOSE: The main aim of this study was to investigate the cobalt (Co) concentrations in urine along 4 months and their relationship with Co concentrations in blood and haemoglobin (adducts) in 34 workers from a hard metal manufacturing plant where metallic Co and Co oxide were used. Furthermore, the excretion kinetics of Co was investigated and the half-lives of Co in blood, plasma and urine were calculated along 18 days of non-exposure in the same workers. METHODS: Co was analysed, in all biological samples, by ICP/MS. RESULTS: Wide fluctuations in the urinary Co concentration were observed throughout the work shift and during the work week. A highly significant linear correlation was found between Co concentration (geometrical mean) in urine samples provided each Thursday (end shift) during 16 subsequent weeks and levels of Co-haemoglobin adducts or blood Co concentrations at the end of the same period. The Co elimination kinetics in globin calculated along 18 days without Co exposure was slow, being related to the physiological metabolism of haemoglobin, while in blood, plasma and urine Co half-lives were 12.3, 9.1 and 5.3 days, respectively. CONCLUSION: Co concentrations in haemoglobin or blood are highly related to the geometrical mean concentration of urinary Co when samples are collected weekly for several subsequent weeks. The biological monitoring of occupational exposure to Co in hard metal facilities provides reliable results by using the Co concentrations in haemoglobin or in whole blood. The urinary findings, though, do not show the same reliability because of their wide daily and weekly fluctuations.

Associations between IVF outcomes and essential trace elements measured in follicular fluid and urine: a pilot study.

PURPOSE: A hypothesis-generating pilot study exploring associations between essential trace elements measured in follicular fluid (FF) and urine and in vitro fertilization (IVF) endpoints. METHODS: We recruited 58 women undergoing IVF between 2007 and 2008, and measured cobalt, chromium, copper, manganese, molybdenum, and zinc in FF (n = 46) and urine (n = 45) by inductively coupled plasma mass spectrometry (ICP-MS). We used multivariable regression models to assess the impact of FF and urine trace elements on IVF outcomes, adjusted for age, body mass index, race, and cigarette smoking. RESULTS: Trace elements were mostly present at lower concentrations in FF than in urine. The average number of oocytes retrieved was positively associated with higher urine cobalt, chromium, copper, and molybdenum concentrations. FF chromium and manganese were negatively associated with the proportion of mature oocytes, yet urine manganese had a positive association. FF zinc was inversely associated with average oocyte fertilization. Urine trace elements were significant positive predictors for the total number of embryos generated. FF copper predicted lower embryo fragmentation while urine copper was associated with higher embryo cell number and urine manganese with higher embryo fragmentation. No associations were detected for implantation, pregnancy, or live birth. CONCLUSIONS: Our results suggest the importance of trace elements in both FF and urine for intermediate, although not necessarily clinical, IVF endpoints. The results differed using FF or urine biomarkers of exposure, which may have implications for the design of clinical and epidemiologic investigations. These initial findings will form the basis of a more definitive future study.

Snapshot of cobalt, chromium and nickel exposure in dental technicians.

BACKGROUND: It is not fully understood where and how people are exposed to sensitizing metals. Much can be learnt from studying occupational settings where metals are handled. OBJECTIVES: To quantify cobalt (Co), chromium (Cr) and nickel (Ni) exposure on the skin and in the air, and urine levels, in dental technicians working with tools and alloys that may result in skin and respiratory exposure. METHODS: The metal skin dose was quantified with acid wipe sampling in dental technicians (n = 13). Air exposure was monitored by personal air sampling. Spot urine samples were collected for 24 h. Metals were analysed with inductively coupled plasma mass spectrometry. RESULTS: Before work, Co was detected on the skin of 10 participants (0.00025-0.0039 µg/cm2 ), and Cr (0.00051-0.011 µg/cm2 ) and Ni (0.0062-0.15 µg/cm2 ) on the skin of all participants. After a 2-h period without hand washing, CoCr-exposed participants had more Co on the skin (p = 0.004) than non-CoCr-exposed participants. Co was found in 10 air samples (0.22-155 µg/m3 ), Cr in nine (0.43-71 µg/m3 ), and Ni in four (0.48-3.7 µg/m3 ). Metal urine concentrations were considered to be normal. CONCLUSIONS: Dental technicians were exposed to Co, Cr and Ni on the skin and through the air, which was not reflected in the urine concentrations in this study. Cobalt skin doses may potentially elicit allergic contact dermatitis and cause sensitization.

Interdependence between urinary cobalt concentrations and hemoglobin levels in pregnant women.

Cobalt is an essential trace element but may cause toxic effects upon occupational or environmental exposure. Women accumulate more cobalt than men at similar exposure levels which may be related to higher metabolic iron loss. During pregnancy these losses are much stronger but their influence on cobalt intake has not been studied. We have studied the associations between changes in hemoglobin and cobalt urinary excretion during pregnancy. 391 pairs of urine and blood samples from pregnant women were collected during the 12th and 32nd weeks of pregnancy and were analyzed for cobalt and hemoglobin. Mean concentrations of urinary cobalt were 0.73 and 1.6 µg/g creatinine during the first and third trimesters, respectively (p<0.001). 84% of pregnant women had higher levels of cobalt in the third than in the first trimester. Cobalt concentrations were negatively associated to hemoglobin levels in the third trimester (p<0.05). Women with higher iron decreases between both trimesters had significant cobalt increases between these two periods. This correspondence involved a statistically significant difference in third trimester mean cobalt concentrations of anemic and non-anemic women, 1.8 and 1.5 µg/g creatinine, respectively (p<0.05). No significant differences between these two groups were found during the first trimester. These results were used to construct generalized additive models both in normal and anemic women. The strong association between the changes of both iron status and cobalt urine levels found in pregnant women may be related to higher intestinal absorption of cobalt at iron depletion such as in the last pregnancy period when iron body demands are high. Possible toxicity effects of these cobalt increases along pregnancy should be considered in cases of populations occupationally or environmentally exposed to this metal.

Predictivity and fate of metal ion release from metal-on-metal total hip prostheses.

Blood metal ion levels in 72 patients with large head metal-on-metal hip arthroplasty were studied to determine the correlation between the values measured in whole blood and urine. Urinary cobalt and chromium levels of 30µg and 21µg, respectively, adjusted to creatinine were found to correspond to the 7µg/l cut-off value that has been accepted in whole blood. Cobalt and chromium levels in whole blood and urine both significantly correlated with increased acetabular component inclination angle over 50 degrees and pain scores. There was no correlation with socket anteversion angle or femoral head diameter. The data support the use of urinary measurement of metal ions adjusted to creatinine to monitor patients with large head metal-on-metal total hip arthroplasty.

Metal release and metal allergy after total hip replacement with resurfacing versus conventional hybrid prosthesis.

BACKGROUND: Metal-on-metal (MOM) total hip arthroplasties were reintroduced because of the problems with osteolysis and aseptic loosening related to polyethylene wear of early metal-on-polyethylene (MOP) arthroplasties. The volumetric wear rate has been greatly reduced with MOM arthroplasties; however, because of nano-size wear particles, the absolute number has been greatly increased. Thus, a source of metal ion exposure with the potential to sensitize patients is present. We hypothesized that higher amounts of wear particles result in increased release of metal ions and ultimately lead to an increased incidence of metal allergy. METHODS: 52 hips in 52 patients (median age 60 (51-64) years, 30 women) were randomized to either a MOM hip resurfacing system (ReCap) or a standard MOP total hip arthoplasty (Mallory Head/Exeter). Spot urine samples were collected preoperatively, postoperatively, after 3 months, and after 1, 2, and 5 years and tested with inductively coupled plasma-sector field mass spectrometry. After 5 years, hypersensitivity to metals was evaluated by patch testing and lymphocyte transformation assay. In addition, the patients answered a questionnaire about hypersensitivity. RESULTS: A statistically significant 10- to 20-fold increase in urinary levels of cobalt and chromium was observed throughout the entire follow-up in the MOM group. The prevalence of metal allergy was similar between groups. INTERPRETATION: While we observed significantly increased levels of metal ions in the urine during the entire follow-up period, no difference in prevalence of metal allergy was observed in the MOM group. However, the effect of long-term metal exposure remains uncertain.

Evaluation of Arsenic and Cobalt Levels in Pediatric Patients Receiving Long-Term Parenteral Nutrition.

This study continues the research in which we determined the concentration of aluminum in children receiving long-term parenteral nutrition (LPN). Since our results were interesting, we decided to assay arsenic (As) and cobalt (Co) in the collected material, which, like aluminum, constitute contamination in the mixtures used in parenteral nutrition. Excesses of these trace elements in the human body are highly toxic, and deficiencies, particularly in the case of Co, can lead to various complications. The aim of this study was to determine the impact of LPN in children on their serum levels of As and Co, as well as the excretion of these elements in urine, and to compare them with a control group of healthy children. The study group consisted of 83 children receiving home parenteral nutrition from two Polish centers, while the control group included 121 healthy children. In both groups, the levels of As and Co in serum and urine were measured. The elemental compositions of the samples were determined using inductively coupled plasma mass spectrometry (ICP-MS). It was demonstrated that the children receiving LPN did not have increased As exposure compared to the controls. Greater exposure compared to the control group was shown for Co. In conclusion, children receiving LPN are not exposed to As, and even though the concentrations of Co in serum and urine were higher in the LPN group than in the healthy controls, neither trace element poses a health threat to children requiring LPN.

Are Metal Ion Levels Elevated After Dual Mobility Acetabular Systems Minimum Five-Year Analysis.

INTRODUCTION: Dual mobility acetabular systems for total hip arthroplasty (THA) have been shown to have decreased dislocation rates and reduced revision rates, but there is controversy over the potential release of sufficient levels of metal ions into the blood to cause adverse local tissue reactions. However, there is a lack of long-term studies analyzing these levels of cobalt and chromium. Therefore, the purpose of this study was to investigate the levels these metal ions at a minimum 5-year follow-up after dual mobility implantation. Specifically, we analyzed: 1. overall blood and urine cobalt levels; 2. overall blood and urine chromium levels; 3. cobalt levels stratified by length of follow-up and various implant-related metrics (i.e., offset, cup size, stem, and neck angle); as well as 4. chromium levels stratified by length of follow-up and these various implant-related metrics. METHODS: A total of 41 patients who underwent THA with modular dual mobility acetabular systems between January 1, 2011, and December 31, 2016, were identified and followed for a mean time of 6 years (range: 5 to 10 years). All patients had well-functioning hips (Harris Hip Scores greater than 90 points (range: 90 to 100 points) and had no evidence of impending radiographic failure or progressive radiolucencies. Cobalt and chromium serum and plasma, blood, as well as urine levels were obtained at final followup. Additional parameters analyzed included: head material and size, stem offset, cup size, as well as stem-neck angle. RESULTS: Concentrations of cobalt were low as the mean blood and urine levels for all patients were 0.6 ± 0.5 µg/L (normal < 1.8 µg/L) and 0.8 ± 0.8 µg/L (normal < 2.8 µg/L), respectively. Only one patient had a minimally elevated blood cobalt level by 0.1 µg/L. These levels were not substantially different when subgroup analyses were performed for ceramic and cobalt-chrome heads. The mean chromium levels in blood and urine were also found to be low for all patients as values were 0.8 ± 0.2 µg/L (normal: < 1.2 µg/L) and 1.2 ± 0.5 ng/milliliter (normal: < 2 ng/L), respectively. Similarly, only one patient had a very slightly elevated blood chromium level of 1.3 µg/L. Additionally, analyses of ceramic or cobalt-chrome heads separately did not demonstrate differences in blood or urine levels. Blood cobalt or chromium concentrations had minimal changes with longer lengths of follow-ups, and with different stem offsets, cup sizes, stems, or neck angles. CONCLUSION: Dual mobility acetabular systems when combined with the two stems studied produced low levels of blood as well as urine cobalt and chromium levels at a minimum follow-up of 5 years (mean: 6 years; range: 5 to 10 years). These results remained below the threshold of normal and clinically insignificant regardless of length of follow-up, head material, or various implant measurements. To the best of our knowledge, this is the first study to demonstrate low levels of metal ions at longer than 4-year follow-up. These data may be of importance to surgeons deciding on the appropriate implants to use for their high-risk patients.

Overexpression of HIF-1α transgene in the renal medulla attenuated salt sensitive hypertension in Dahl S rats.

Hypoxia inducible factor (HIF)-1α-mediated gene activation in the renal medulla in response to high salt intake plays an important role in the control of salt sensitivity of blood pressure. High salt-induced activation of HIF-1α in the renal medulla is blunted in Dahl S rats. The present study determined whether the impairment of the renal medullary HIF-1α pathway was responsible for salt sensitive hypertension in Dahl S rats. Renal medullary HIF-1α levels were induced by either transfection of HIF-1α expression plasmid or chronic infusion of CoCl2 into the renal medulla, which was accompanied by increased expressions of anti-hypertensive genes, cyclooxygenase-2 and heme oxygenase-1. Overexpression of HIF-1α transgenes in the renal medulla enhanced the pressure natriuresis, promoted the sodium excretion and reduced sodium retention after salt overload. As a result, hypertension induced by 2-week high salt was significantly attenuated in rats treated with HIF-1α plasmid or CoCl2. These results suggest that an abnormal HIF-1α in the renal medulla may represent a novel mechanism mediating salt-sensitive hypertension in Dahl S rats and that induction of HIF-1α levels in the renal medulla could be a therapeutic approach for the treatment of salt-sensitive hypertension.

Occupational exposure to cobalt is not associated with incipient signs of dilated cardiomyopathy in a Belgian refinery.

BACKGROUND: Excessive absorption of cobalt has been associated with cases of dilated cardiomyopathy in the past, but it is unclear whether occupationally exposed populations are at risk. OBJECTIVE: To assess the possible relationship between occupational exposure to cobalt and incipient signs of dilated cardiomyopathy. METHODS: A cross-sectional survey was conducted in a cobalt production facility in Belgium constituting one of the largest occupational populations worldwide (n=256 male workers). Exposure to cobalt was assessed by measuring urinary cobalt concentration (µg/gcreat), reflecting recent exposure, and by computing an integrated exposure index (µg/gcreat×years), reflecting long-term exposure. The effect on the myocardium was investigated by echocardiography and electrocardiography, and dose-effect relations with cobalt exposure were traced by multiple regression analysis. RESULTS: No dose-effect relationship between exposure to cobalt and parameters reflecting dilated cardiomyopathy was found in a population of workers characterised by a median recent cobalturia of 4 µg/gcreat and a median long-term cobalturia of 100 µg/gcreat×years. A reduction in the dimensions of the left ventricular internal cavity was associated with recent exposure to cobalt. CONCLUSIONS: Occupational exposure to cobalt does not appear associated with incipient signs of dilated cardiomyopathy within the gradient of exposure recorded in this population.

Evaluation of chromium, cobalt and manganese in biological samples (scalp hair, blood, and urine) of Pakistani viral hepatitis (A-E) patients and controls.

BACKGROUND: The aim of the present study was to compare the level of chromium (Cr), cobalt (Co), and manganese (Mn) in biological samples (blood, urine, and scalp hair) of patients suffering from different types of viral hepatitis (A, B, C, D, and E; n = 521) of both genders, ages ranging from 31 - 45 years. For comparative study, 255 age-matched control subjects of both genders residing in the same city were selected as referents. METHODS: The digests of all biological samples were analysed for Cr, Co, and Mn by electrothermal atomic absorption spectrometry (ETAAS). The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and compared with those values obtained by conventional wet acid digestion method on same CRMs. RESULTS: The results of this study showed that the mean values of Cr, Co, and Mn were higher in blood and scalp hair samples of hepatitis patients than in age-matched control subjects. The urinary levels of these elements were found to be higher in the hepatitis patients than in the age-matched healthy controls (p <0.001). CONCLUSIONS: These results are consistent with literature-reported data, confirming that the overload of these trace elements can directly cause lipid peroxidation and eventually hepatic damage.

Breast milk metal ion levels in a young and active patient with a metal-on-metal hip prosthesis.

Metal-on-metal resurfacing arthroplasty of the hip has been used increasingly over the last 10 years in younger active patients. The dissolution of the metal wear particles results in measurable increases in cobalt and chromium ions in the serum and urine of patients with a metal-on-metal bearing. We measured the cobalt, chromium, and molybdenum ion levels in urine; serum; and breast milk in a young and active patient with a metal-on-metal hip prosthesis after a pathologic fracture of the femoral neck. Metal-on-metal hip prosthesis leads to increasing levels of molybdenum in breast milk in the short-term follow-up. There are no increasing levels of chromium and cobalt ions in breast milk. Besides the already known elevated concentrations in serum of chromium and cobalt after implantation of a metal-on-metal hip prosthesis, we found no increasing levels of chromium and cobalt in urine.