Occupational Metal Exposure Research Articles

Occupational metal exposures, smoking and risk of diabetes and prediabetes.

Metal exposure and tobacco smoking have been independently associated with diabetes, but no study has been conducted to investigate the interaction between them on the risk of diabetes. To investigate the effect of occupational exposure to metals, and potential effect modification by smoking, on the risk of diabetes and prediabetes in a cohort of Chinese male workers. We assessed metal exposure and tobacco smoking at baseline in the Jinchang Cohort of male workers. We used Poisson regression analyses to estimate the interaction between smoking and metal exposures based on occupations, which we grouped according to the measured urinary metal levels. Among the 26008 study subjects, compared with non-smokers, the adjusted prevalence ratio (PR) for diabetes was 1.8 [95% confidence interval (CI) 1.3-2.4] for smokers of >40 pack-years. The adjusted PRs were 1.2 (95% CI 1.1-1.4) among mining/production workers and 2.7 (95% CI 2.4-3.0) among smelting/refining workers, both compared with office workers. There was significant effect modification under the additive model between smoking and metal exposure on the prevalence of diabetes (Pinteraction = 0.001), with an adjusted PR of 3.6 (95% CI 2.4-5.4) for those with >40 pack-years of smoking who had the highest metal exposures, whereas no significant interaction was observed for prediabetes. Both exposure to metals and heavy smoking were associated with an increased prevalence of diabetes in this large cohort of male workers. There was also strong interaction between these two exposures in affecting diabetes risk that should be confirmed in future studies.

The relationship between occupational metal exposure and arterial compliance.

The objective of this study was to evaluate the relationship between cumulative occupational exposure to various metals and arterial compliance in welders. The observational follow-up study consisted of 25 subjects. Levels of nickel (Ni), lead, cadmium, manganese, and arsenic from toenails were assessed using mass spectrometry. Arterial compliance as reflected by augmentation index (AIx) was measured using SphygmoCor Px Pulse Wave Analysis System. Linear regression models were used to assess the associations. For every 1 unit increase in log-transformed toenail Ni, there was a statistically significant 5.68 (95% confidence interval, 1.38 to 9.98; P = 0.01) unit increase in AIx. No significant associations were found between AIx and lead, cadmium, manganese, and arsenic. Cumulative Ni exposure is associated with increased arterial stiffness in welders and may increase risk of adverse cardiovascular outcomes.

Metal Allergy—A Review on Exposures, Penetration, Genetics, Prevalence, and Clinical Implications

The prevalence of metal allergy is high in the general population, and it is estimated that up to 17% of women and 3% of men are allergic to nickel and that 1-3% are allergic to cobalt and chromium. Among dermatitis patients, the prevalence of metal allergy is even higher. Metal allergy is mainly an environmental disorder although null mutations in the filaggrin gene complex were recently found to be associated with nickel allergy and dermatitis. Environmental metal exposures include jewelry, buttons, clothing fasteners, dental restorations, mobile phones, and leather. Although consumer exposure is responsible for most cases of metal allergy, the importance of occupational metal exposure remains present and should always be taken into consideration when one interprets allergic patch test reactions to metals. Traditionally, nickel, cobalt, and chromium have been the most important contact allergens. However, recently, gold and palladium have drawn much attention as the prevalence of contact allergy to these metals is high. Palladium allergy is mainly a result of cross-sensitization to nickel, whereas gold allergy is rarely clinically relevant when one takes its high prevalence into account. The epidemiology of metal allergy has recently changed in Europe as nickel allergy among ear-pierced Danish women has decreased following regulatory intervention on nickel release from consumer products. In the United States, the prevalence of nickel allergy is still increasing, which may be explained by the absence of regulation. The prevalence of chromium allergy is increasing in the United States, Singapore, and Denmark among dermatitis patients. This increase is significantly associated with leather exposure in Denmark. Metal allergy may result in allergic contact dermatitis and systemic allergic (contact) dermatitis. Furthermore, metal allergy has been associated with device failure following insertion of intracoronary stents, hip and knee prostheses, as well as other implants. This area is in need of more research.

DIFFUSE ALVEOLAR HEMORRHAGE ASSOCIATED WITH DENDRIFORM PULMONARY OSSIFICATION

INTRODUCTION: Diffuse pulmonary ossification is a rare entity that presents with bone formation within the lung parenchyma. Patients are generally asymptomatic and diagnosis is usually made at autopsy, but patients can rarely present with dyspnea, cough, and hemoptysis. Although a specific etiology has not been established, it has been associated with acute and chronic lung disease, heart disease and other systemic disorders. Diffuse alveolar hemorrhage (DAH) can complicate a large number of clinical conditions and has not previously been associated with pulmonary ossification. We describe a case of diffuse pulmonary ossification in association with diffuse alveolar hemorrhage in a man with significant occupational metal exposure.

Central nervous system effects of metal oxide nanoparticles applied into the airways of rats

Event Abstract Back to Event Central nervous system effects of metal oxide nanoparticles applied into the airways of rats András Papp1* and Leila Sarkozi1 1 Department of Public Health, University of Szeged , Hungary Nervous system is a target for environmental xenobiotics including the heavy metals manganese, lead and cadmium. In casting, welding, waste incineration etc., metals generate oxide fumes consisting of microscopic and submicroscopic airborne solid particles, inhalation of which is a major way of occupational metal exposure. In the studies presented, nanoparticulate (mean diameter 20-30 nm) metal oxides (MnO2, CdO2, PbO) were synthesized, suspended in distilled water and instilled into the trachea of rats 5 times a week for 6 weeks (metal doses per kg b.w.: 2.63 and 5.26 mg Mn; 0.04 and 0.4 mg Cd; 2 and 4 mg Pb). At the end, the rats had an open field spontaneous motility test, and were prepared in urethane anaesthesia for recording spontaneous and stimulus-evoked cortical activity. In the higher dose Mn-treated rats, the percentage of open field ambulation and rearing decreased while local activity and immobility increased. Cd had no effect on motility, whereas Pb caused dose-dependently decreased rearing and somewhat increased ambulation. Spontaneous cortical activity was shifted by all three metals to higher frequencies. Cortical evoked potentials had lengthened latency in the higher dose rats, more pronounced with Mn and Cd than with Pb. The frequency dependence of the somatosensory evoked potential latency was increased by Cd and Pb but not by Mn. These effects were similar to previous results with oral application of the same metals. Nanoparticulate metals had apparently access form the airways to the CNS. Human nervous system damage by metal fumes inhalation can be modelled this way. Conference: 12th Meeting of the Hungarian Neuroscience Society, Budapest, Hungary, 22 Jan - 24 Jan, 2009. Presentation Type: Poster Presentation Topic: Pathophysiology and neurology - non-degenerative disorders Citation: Papp A and Sarkozi L (2009). Central nervous system effects of metal oxide nanoparticles applied into the airways of rats. Front. Syst. Neurosci. Conference Abstract: 12th Meeting of the Hungarian Neuroscience Society. doi: 10.3389/conf.neuro.01.2009.04.126 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 04 Mar 2009; Published Online: 04 Mar 2009. * Correspondence: András Papp, Department of Public Health, University of Szeged, Szeged, Hungary, ppp@puhe.szote.u-szeged.hu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers András Papp Leila Sarkozi Google András Papp Leila Sarkozi Google Scholar András Papp Leila Sarkozi PubMed András Papp Leila Sarkozi Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Association of expired nitric oxide with urinary metal concentrations in boilermakers exposed to residual oil fly ash.

Exposure to metal-containing particulate matter has been associated with adverse pulmonary responses. Metals in particulate matter are soluble, hence are readily recovered in urine of exposed individuals. This study investigated the association between urinary metal concentrations and the fractional concentration of expired nitric oxide (F(E)NO) in boilermakers (N = 32) exposed to residual oil fly ash (ROFA). Subjects were monitored at a boiler overhaul site located in the New England area, USA. F(E)NO and urine samples were collected pre- and post-workshift for 5 consecutive workdays. Metals investigated included vanadium (V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), and lead (Pb). The median F(E)NO was 7.5 ppb (95% CI: 7.4-8.0), and the median creatinine-adjusted urinary metal concentrations (mug/g creatinine) were: vanadium, 1.37; chromium, 0.48; manganese, 0.30; nickel, 1.52; copper, 3.70; and lead, 2.32. Linear mixed-effects models indicated significant inverse exposure-response relationships between log F(E)NO and the log-transformed urinary concentrations of vanadium, manganese, nickel, copper, and lead at several lag times, after adjusting for smoking status. Urine samples may be utilized as a biomarker of occupational metal exposure. The inverse association between F(E)NO and urinary metal concentrations suggests that exposure to metals in particulate matter may have an adverse effect on respiratory health.

The association of expired nitric oxide with occupational particulate metal exposure

Toxicologic studies have shown that soluble transition metals in residual oil fly ash (ROFA) can induce pulmonary injury. In this study, we investigated the association between the fractional concentration of expired nitric oxide (F ENO) and exposure to metal constituents of particulate matter with an aerodynamic mass median diameter⩽2.5 μm (PM 2.5) in boilermakers exposed to ROFA and metal fume. Metals investigated included vanadium, chromium, manganese, nickel, copper, and lead. Subjects were monitored for 5 consecutive days during boiler repair overhauls in 1999 ( n=20) and 2000 ( n=14). In 1999, we found a significant inverse association between log-transformed F ENO and PM 2.5 metal concentrations. Log F ENO changed by −0.03 (95% CI: −0.04, −0.01), −0.56 (95% CI: −0.88, −0.24), −0.09 (95% CI: −0.16, −0.02), and −0.04 (95% CI: −0.07, −0.02) per μg/m 3 of PM 2.5 vanadium, chromium, manganese, and nickel, respectively. In 2000, no significant associations were observed, most likely due to exposure misclassification resulting from the use of respirators. The inverse association between PM 2.5 metal exposure and F ENO in subjects with limited respirator usage suggests that soluble transition metals might be partially responsible for the adverse pulmonary responses seen in workers exposed to ROFA.

Are environmental factors important in primary systemic vasculitis? A case-control study.

To investigate the association between primary systemic vasculitis (PSV) and environmental risk factors. Seventy-five PSV cases and 273 controls (220 nonvasculitis, 19 secondary vasculitis, and 34 asthma controls) were interviewed using a structured questionnaire. Factors investigated were social class, occupational and residential history, smoking, pets, allergies, vaccinations, medications, hepatitis, tuberculosis, and farm exposure in the year before symptom onset (index year). The Standard Occupational Classification 2000 and job-exposure matrices were used to assess occupational silica, solvent, and metal exposure. Stepwise multiple logistic regression was used to calculate the odds ratio (OR) and 95% confidence interval (95% CI) adjusted for potential confounders. Total PSV, subgroups (47 Wegener's granulomatosis [WG], 12 microscopic polyangiitis, 16 Churg-Strauss syndrome [CSS]), and antineutrophil cytoplasmic antibody (ANCA)-positive cases were compared with control groups. Farming in the index year was significantly associated with PSV (OR 2.3 [95% CI 1.2-4.6]), with WG (2.7 [1.2-5.8]), with MPA (6.3 [1.9-21.6]), and with perinuclear ANCA (pANCA) (4.3 [1.5-12.7]). Farming during working lifetime was associated with PSV (2.2 [1.2-3.8]) and with WG (2.7 [1.3-5.7]). Significant associations were found for high occupational silica exposure in the index year (with PSV 3.0 [1.0-8.4], with CSS 5.6 [1.3-23.5], and with ANCA 4.9 [1.3-18.6]), high occupational solvent exposure in the index year (with PSV 3.4 [0.9-12.5], with WG 4.8 [1.2-19.8], and with classic ANCA [cANCA] 3.9 [1.6-9.5]), high occupational solvent exposure during working lifetime (with PSV 2.7 [1.1-6.6], with WG 3.4 [1.3-8.9], and with cANCA 3.3 [1.0-10.8]), drug allergy (with PSV 3.6 [1.8-7.0], with WG 4.0 [1.8-8.7], and with cANCA 4.7 [1.9-11.7]), and allergy overall (with PSV 2.2 [1.2-3.9], with WG 2.7 [1.4-5.7]). No other significant associations were found. A significant association between farming and PSV has been identified for the first time. Results also support previously reported associations with silica, solvents, and allergy.

Issues Related to Studying Occupational Metal Exposures and Parkinson’s Disease

Issues Related to Studying Occupational Metal Exposures and Parkinson’s Disease

MECHANISMS OF NEPHROTOXICITY FROM METAL COMBINATIONS: A REVIEW

The common environmental pollutants arsenic, lead, and cadmium are each known to induce chronic renal disease and the molecular mechanisms of such toxic events are being clarified. Nephrotoxicity of these metals is due to the fact that urinary elimination is a main route of excretion, and the proximal tubules are especially sensitive due to their high reabsorptive activity. Renal pathological effects of these metals vary with the chemical form of the metal, the dose, and whether the exposure is acute or chronic in nature. The few isolated studies of combined metal exposures indicate that these pathological effects may be altered due to unknown interactions of these metals within the kidney. Biological factors within the cell such as metal binding proteins and inclusion bodies may also influence metal-metal interactions. Further research is needed to specify the parameters or criteria by which metal interactions is to be assessed for unique biological response patterns to aid in the risk assessment analysis of environmental and occupational metal exposures.

Enhancement of cytotoxicity and clastogenicity of l-DOPA and dopamine by manganese and copper

It is an increasingly popular hypothesis that the continued degeneration of dopaminergic neurons in Parkinson's disease (PD) may be the consequence of aberrant oxidation of dopamine and resultant generation of DNA reactive species in PD patients receiving levodopa ( l-DOPA) therapy. Occupational metal exposure, particularly to manganese, is a risk factor for Parkinsonism and manganese has been shown to be a true catalyst for dopamine oxidation lending support to this hypothesis. In the present studies, we demonstrate that the antiproliferative activity of l-DOPA and dopamine on Chinese Hamster V79 cells is enhanced by at least an order of magnitude by concomitant exposure to manganese chloride or copper sulfate (500 μM), but not to iron(III) or zinc. Moreover, manganese and copper confer strong clastogenic properties to both compounds as detected in an in vitro micronucleus assay in V79 cells. Metal catalyzed oxidation of drug was associated with the development of a brown-black particulate substance presumed to be a melanin precursor formation. The extent of formation of this precursor paralleled clastogenicity. Metal-enhanced effects were completely antagonized by the concurrent addition of cysteine or reduced glutathione to the cultures. These findings are in support of the hypothesis that aberrant oxidation of dopamine resulting from non-physiological levels of catalytic metals may contribute to the death of dopaminergic neurons and further suggest that oxidation-dependent DNA damage may be the basis for this cell death.

Intra- and inter-rater agreement in the assessment of occupational exposure to metals.

Among the methods of retrospective occupational exposure assessment, expert review is considered the most accurate. Although expert review provides a more objective measure of exposure, depending on the exposure of interest it may still result in a significant degree of misclassification. To evaluate the reliability in occupational metal exposure assessment by expert review, we analysed job history data from a case-control study of a neurological disease. First, one industrial hygienist (IH) did an initial exposure assessment of the metals copper, iron and lead, blinded to case-control status, for 608 subjects who had 3033 total jobs. We then compared exposure assessments from the original review with a second blinded review of 60 job histories (306 jobs) by the same IH (intra-rater) and of 64 job histories (361 jobs) by a different IH (inter-rater). The per cent agreements for the intra-IH comparisons were 89.6 for copper, 87.9 for iron and 94.6 for lead, whereas the inter-IH per cent agreements were 86.4 for copper, 81.1 for iron and 76.2 for lead. Based on the assumption that reliability is related to validity, we calculated an estimate of misclassification of metal exposure by one IH. Our exposure misclassification estimates show a sizable attenuation of the odds ratio, with the expected bias similar for copper and iron when using either intra- or inter-reliability results to estimate misclassification. Our results suggest that variation in the expert assessment of metal exposure is due mainly to the difficulties involved in transforming an occupational history into an estimate of exposure.

An investigation of occupational metal exposure in thermal spraying processes

A cross-sectional study of 34 workers engaged in thermal spraying at six worksites was undertaken in order to determine levels of exposure to and uptake of metals during different metal spraying activities. Levels of exposure to cobalt, chromium and nickel were highest in plasma sprayers and, on occasions exceeded UK Occupational Exposure Limits. Exposure to metals during detonation gun and electric arc spraying was better controlled and levels remained below the relevant Occupational Exposure Limits throughout the study period. Urinary levels of cobalt and nickel mirrored the airborne concentrations and the highest urine concentrations were again found in plasma sprayers. Urinary chromium levels were highest in electric are sprayers, which may also reflect an increased body burden in this group due to a longer history of exposure. The findings clearly indicate that exposure to and uptake of metals may exceed UK Occupational Limits or Standards when spraying is performed manually or semi-automatically and where control relies on local exhaust ventilation (LEV) and personal respiratory protective equipment (RPE).

Urinary α1-Microglobulin, β2-Microglobulin, and Retinol-Binding Protein Levels in General Populations in Japan with References to Cadmium in Urine, Blood, and 24-Hour Food Duplicates

Possible cadmium (Cd) exposure-associated changes in urinary levels of low-molecular-weight proteins mere studied in nonsmoking and nondrinking female members of the general Japanese population (378 subjects with no known occupational heavy metal exposure) who lived at 19 study sites (all without any known environmental heavy metal pollution) in 13 prefectures throughout Japan. The external Cd dose was evaluated in terms of daily Cd intake via food (Cd-F), whereas Cd levels in blood (Cd-B) and urine (Cd-U) were taken as internal dose indicators. When the subjects were classified according to Cd-F into three groups with "low" (20.4 μg/day as a geometric mean of 97 women), "middle" (35.0 μg/day, 120 women) and "high" (67.0 μg/day, 66 women) exposure, both Cd-B and Cd-U increased in parallel with the changes in Cd-F. However, there were no dose-dependent changes in β2-microglobulin or retinol-binding protein levels in urine. α1-Microglobulin levels appeared to increase, but the distribution of the cases above the two cutoff levels of 9.6 and 15.8 μg/mg creatinine among the three Cd-F groups did not show any bias. Overall, it was concluded that there was no apparent Cd exposure-associated elevation in urinary low-molecular-weight protein levels in the study population.

Amyotrophic lateral sclerosis and occupational heavy metal exposure: a case-control study.

A retrospective case-control study of occupational heavy metal exposure was conducted using 66 amyotrophic lateral sclerosis (ALS) patients and 66 age- and sex-matched controls. Cases were ascertained primarily through a neurology support and research clinic. The self-administered questionnaire probed potential exposure to nine heavy metals: aluminum, lead, lead alkyl, magnesium, manganese, mercury, mercury alkyl, nickel and selenium. Using McNemar's test and a Mantel Haenszel extended analysis, no association was found between heavy metal exposure and the pathogenesis of ALS in this patient population. Demographic factors, fracture history, immunizations, travel and other variables were similar in ALS patients and controls.