Health risk assessment of occupational exposure to heavy metals in a steel casting unit of a steelmaking plant using Monte-Carlo simulation technique.

The present work aimed to evaluate the health risks of occupational exposure to heavy metals in a steel casting unit of a steel plant. To determine occupational exposure to heavy metals, personal air samples were taken from the workers' breathing zones using the National Institute for Occupational Safety and Health method. Noncancer and cancer risks due to the measured metals were calculated according to the United States Environmental Protection Agency procedures. The results indicated that the noncancer risks owing to occupational exposure to lead (Pb) and manganese were higher than the recommended value in most of the workstations. The estimated cancer risk of Pb was also higher than the allowable value. Moreover, the results of sensitivity analysis indicated that the concentration, inhalation rate, and exposure duration were the most influencing variables contributing to the calculated risks. It was thus concluded that the present control measures were not adequate and further improvements were required for reducing the exposure levels.

Bladder cancer and occupational exposure to metalworking fluid mist: a counter-matched case-control study in French steel-producing factories.

OBJECTIVES: To assess the relationship between occupational exposure to metalworking fluids (MWFs) in the steel-producing industry and bladder cancer incidence. METHODS: A nested case-control study on bladder cancer was set up in a cohort of workers from six French steel-producing factories. Three controls were randomly selected for each incident bladder cancer case diagnosed from 2006 to 2012. Controls were matched to cases on age at diagnosis and counter-matched on a surrogate measure of exposure to MWFs derived from a job-exposure matrix. Cases (n=84) and controls (n=251) were face-to-face interviewed. Experts assessed occupational exposure to MWFs (straight, soluble and synthetic) using questionnaires and reports from factory visits. Occupational exposures were based on three metrics: duration, frequency-weighted duration and cumulative exposure index. Conditional multiple logistic regressions were used to determine ORs and 95% CIs, taking non-occupational and occupational exposure into account. RESULTS: In the 25 years before diagnosis, ORs increased significantly with duration of exposure to straight MWFs (OR=1.13 (1.02-1.25)) and increased with frequency-weighted duration of exposure to straight MWFs (OR=1.44 (0.97-2.14)). These results remained valid after adjusting for duration of smoking, average number of cigarettes smoked per day, time since smoking cessation and exposure to polycyclic aromatic hydrocarbons (PAHs). ORs also increased with soluble MWFs but not significantly. No significant association was found with older exposures to MWFs or with exposure to synthetic MWFs. CONCLUSION: The increased risk of bladder cancer observed among workers exposed to straight MWFs and to a lesser extent to soluble MWFs may be explained by the presence of carcinogens (such as PAH) in mineral oils component of straight and soluble oils. Prevention therefore remains necessary in sectors using MWFs.

Chemical fraction, leachability, and bioaccessibility of heavy metals in contaminated soils, Northeast China.

Heavy metals in urban soils may pose risks to both urban environment and human health. However, only a fraction of heavy metals in soil is mobile and/or bioavailable for plant uptake and human ingestion. This study evaluates the chemical fraction and potential mobility and bioaccessibility of heavy metals (Cd, Cr, Cu, Pb, and Zn) in the contaminated urban topsoils from steel-industrial city (Anshan), Northeastern China. Chemical forms of heavy metals in soils are determined using Tessier sequential extraction technique. The toxicity characteristic leaching procedure (TCLP), ethylenediaminetetraacetic acid (EDTA), and US Pharmacopeia methodology (USPM) are used to determine the operationally defined potentially mobile and bioaccessible metal fractions, respectively. Sequential extraction results show that Cd has the highest percentage of exchangeable form, whereas Cr primarily exists in residual form. The non-residual fraction of heavy metals increases in the order of Cr < Cu < Pb < Zn < Cd. The leachability of heavy metals evaluated by TCLP test indicates that Cd, Zn, Cu, and Pb have much higher mobile than Cr. The bioavailability of heavy metals determined by EDTA extraction decreases in the order of Pb > Cu ≅ Zn > Cd > Cr. The order of bioaccessibility determined by USPM extraction is Pb = Cu > Zn > Cd > Cr. The Cr exhibits the lowest leachability and bioaccessibility among the investigated metals. The Pb has the highest bioaccessibility, indicating higher potential hazard for the human health. There are significant relationships between the EDTA- and USPM-extractable metals (Cd, Cu, Pb, and Zn) and the sum of first three steps of sequential extraction. Highly significant correlation is found between amounts of EDTA-extractable Cd, Cu, Pb, and Zn and USPM-extractable metals. The result suggests that EDTA extraction can be helpful to estimate the bioaccessibility of heavy metals for human ingestion. Introduction of mobile and human bioaccessible concentrations into risk assessments can give more realistic implications for urban environmental management.

Polishing surgical metal pieces, granulomatosis and mineralogical analysis.

This report describes the case of a 44-year-old man with pulmonary nodules whose histological analysis initially suggested tuberculosis. The Mycobacterium tuberculosis (MT) culture was negative and a questionnaire revealed a professional activity of brushing and polishing surgical instruments without any protection for 7 years.  A mineralogical analysis by optical and electron microscopy was performed on both a healthy lung tissue biopsy and a lung nodule in a paraffin block. Electron microscopy analysis revealed the presence of metal particles (iron oxide, titanium oxide, aluminum oxide and steel) in both samples. This study suggests that mineralogical analysis combined with a questionnaire on dust exposure could help redirect the diagnosis of a dust-related disease.

Magnetic Field Interactions of Military and Law Enforcement Bullets at 1.5 and 3 Tesla.

OBJECTIVES: There are significant numbers of military and law enforcement bullets containing ferromagnetic materials. This study aimed to assess the magnetic field interactions for a representative sample of military and law enforcement ballistic objects at 1.5 and 3 tesla (T) to create a magnetic resonance imaging (MRI) compatibility database. METHODS: Twenty-nine different bullets underwent MRI evaluation. The deflection angle method and a qualitative torque scale were used. The samples were representative of those commonly used in the North Atlantic Treaty Organization (NATO) military forces (e.g., 5.56 mm NATO), law enforcement agencies (e.g., 9 mm Parabellum), and encountered in war injuries and crime-related trauma (e.g., 7.62 mm Kalashnikov). RESULTS: At all static magnetic field strengths, all non-nickel- and nonsteel-containing bullets exhibited no movement (deflection angle = 0°; torque = 0), whereas eight bullets containing steel core, steel jacket, or nickel jacket exhibited substantial magnetic field interactions over and above what might be regarded as safe in vivo (deflection angle = 90°; torque = 4+). CONCLUSION: Military and law enforcement non-nickel- or nonsteel-containing bullets appear to be safe for patients in MRI system at 1.5 and 3 T. On the other hand, nickel- and steel-containing bullets exhibit movements that are considered potentially unsafe for patients in an MRI environment.

Hypersensitivity reactions to implanted metal devices: facts and fictions

The use of metals in the medical field has become increasingly prevalent over the past few decades. Patients find themselves being exposed metals in a variety of ways, ranging from external exposure to instruments such as the stainless steel in surgical blades to internal exposure via medical devices being implanted in their bodies. There has been growing interest in the possibility of developing hypersensitivity reactions to constituent metals in medical implant devices, both in cutaneous and systemic forms. Hypersensitivity reactions to metals are uncommon, but they are reported and require appropriate evaluation and management, particularly if they are symptomatic. In view of the lack of consensus in the field on the appropriate steps to evaluate and manage patients with suspected metal hypersensitivity reactions, this review aims to analyze current evidence on hypersensitivity reactions to metallic implants in orthopedic surgery, endovascular surgery, obstetrics and gynecology, and dental surgery (AU)

El empleo de metales dentro de la medicina ha ido aumentando de forma progresiva en las últimas décadas. Los pacientes se exponen a metales de diferentes formas desde fuentes externas, como instrumental quirúrgico como el presente en las hojas de acero de los bisturíes, hasta implantes metálicos. Como consecuencia de ello se está produciendo un interés creciente por la posibilidad de desarrollar reacciones de hipersensibilidad a metales presentes en los materiales y objetos implantados, tanto en forma de reacciones cutáneas como sistémicas. Las reacciones de hipersensibilidad a metales no son frecuentes, pero pueden desarrollarse, y por ello, requieren de un diagnóstico y tratamiento adecuado, especialmente en aquellos pacientes que desarrollen síntomas. No existe un consenso en el proceso diagnóstico ni en el tratamiento de estas reacciones en los pacientes con sospecha de alergia a metales. Esta revisión tiene por objeto actualizar la evidencia existente sobre las reacciones de hipersensibilidad a implantes metálicos en cirugía ortopédica, cirugía endovascular, cirugía obstétrica y ginecológica (OB-GYN) así como la dental (AU)

Assessment of the Biological Effects of Welding Fumes Emitted From Metal Active Gas and Manual Metal Arc Welding in Humans.

OBJECTIVE: Emissions from a particular welding process, metal inert gas brazing of zinc-coated steel, induce an increase in C-reactive protein. In this study, it was investigated whether inflammatory effects could also be observed for other welding procedures. METHODS: Twelve male subjects were separately exposed to (1) manual metal arc welding fumes, (2) filtered air, and (3) metal active gas welding fumes for 6 hours. Inflammatory markers were measured in serum before, and directly, 1 and 7 days after exposure. RESULTS: Although C-reactive protein concentrations remained unchanged, neutrophil concentrations increased directly after exposure to manual metal arc welding fumes, and endothelin-1 concentrations increased directly and 24 hours after exposure. After exposure to metal active gas and filtered air, endothelin-1 concentrations decreased. CONCLUSIONS: The increase in the concentrations of neutrophils and endothelin-1 may characterize a subclinical inflammatory reaction, whereas the decrease of endothelin-1 may indicate stress reduction.

Pulmonary fibrosis and exposure to steel welding fume.

BACKGROUND: Arc welders who have been exposed to high concentrations of steel welding fume for prolonged periods of time may develop pulmonary fibrosis but the nature of the fibrotic changes has been debated over the last 80 years without any clear international consensus. AIMS: To characterize the nature of the pulmonary fibrosis that develops in response to steel welding fume exposure and to provide a working hypothesis that would explain the findings of the existing research, to provide a platform for future research and to inform future occupational and clinical management of welders with pulmonary effects from welding fume. METHODS: Review of the world literature on pulmonary fibrosis and welding of steel in all languages using PubMed, with further secondary search of references in the articles found in the primary search. Google and Reference Manager were used as further confirmatory search tools. RESULTS: Only case series and case reports were found but these provided consistent evidence that the consequence of exposure to steel welding fume at high levels for a prolonged period of time is a type of pulmonary fibrosis similar to, and possibly the same as, respiratory bronchiolitis which eventually develops into desquamative interstitial pneumonia with ongoing exposure. CONCLUSIONS: Steel welding fume may cause an occupational respiratory bronchiolitis which may develop into de squamative interstitial pneumonia with ongoing exposure. This concept may explain the difficulties in interpreting the wider literature on welding fume and lung function at lower exposures and may also explain the increased risk of lung cancer in welders.

PENELOPE-2008 Monte Carlo simulation of gamma exposure induced by 6°Co and NORM-radionuclides in closed geometries.

We present Monte Carlo simulations of the gamma exposure in closed rooms made of steel or concrete and contaminated by 6°Co or NORM radionuclides. The computer code PENELOPE-2008 (Salvat et al., 2009) was used. Our simulations for 6°Co suggest considering detailed Monte Carlo simulations in future recommendations on clearance and exemption of materials with low radioactivity. For NORM nuclides our calculations suggest that Monte Carlo simulations are a possible alternative in case a material fails the dose rate criteria by using the RP 112 screening method.

Evolutionary age of repetitive element subfamilies and sensitivity of DNA methylation to airborne pollutants.

BACKGROUND: Repetitive elements take up >40% of the human genome and can change distribution through transposition, thus generating subfamilies. Repetitive element DNA methylation has associated with several diseases and environmental exposures, including exposure to airborne pollutants. No systematic analysis has yet been conducted to examine the effects of exposures across different repetitive element subfamilies. The purpose of the study is to evaluate sensitivity of DNA methylation in differentially‒evolved LINE, Alu, and HERV subfamilies to different types of airborne pollutants. METHODS: We sampled a total of 120 male participants from three studies (20 high-, 20 low-exposure in each study) of steel workers exposed to metal-rich particulate matter (measured as PM10) (Study 1); gas-station attendants exposed to air benzene (Study 2); and truck drivers exposed to traffic-derived elemental carbon (Study 3). We measured methylation by bisulfite-PCR-pyrosequencing in 10 differentially‒evolved repetitive element subfamilies. RESULTS: High-exposure groups exhibited subfamily-specific methylation differences compared to low-exposure groups: L1PA2 showed lower DNA methylation in steel workers (P=0.04) and gas station attendants (P=0.03); L1Ta showed lower DNA methylation in steel workers (P=0.02); AluYb8 showed higher DNA methylation in truck drivers (P=0.05). Within each study, dose-response analyses showed subfamily-specific correlations of methylation with exposure levels. Interaction models showed that the effects of the exposures on DNA methylation were dependent on the subfamily evolutionary age, with stronger effects on older LINEs from PM10 (p‒interaction=0.003) and benzene (p‒interaction=0.04), and on younger Alus from PM10 (p-interaction=0.02). CONCLUSIONS: The evolutionary age of repetitive element subfamilies determines differential susceptibility of DNA methylation to airborne pollutants.

Effects of airborne pollutants on mitochondrial DNA methylation.

BACKGROUND: Mitochondria have small mitochondrial DNA (mtDNA) molecules independent from the nuclear DNA, a separate epigenetic machinery that generates mtDNA methylation, and are primary sources of oxidative-stress generation in response to exogenous environments. However, no study has yet investigated whether mitochondrial DNA methylation is sensitive to pro-oxidant environmental exposures. METHODS: We sampled 40 male participants (20 high-, 20 low-exposure) from each of three studies on airborne pollutants, including investigations of steel workers exposed to metal-rich particulate matter (measured as PM1) in Brescia, Italy (Study 1); gas-station attendants exposed to air benzene in Milan, Italy (Study 2); and truck drivers exposed to traffic-derived Elemental Carbon (EC) in Beijing, China (Study 3). We have measured DNA methylation from buffy coats of the participants. We measured methylation by bisulfite-Pyrosequencing in three mtDNA regions, i.e., the transfer RNA phenylalanine (MT-TF), 12S ribosomal RNA (MT-RNR1) gene and "D-loop" control region. All analyses were adjusted for age and smoking. RESULTS: In Study 1, participants with high metal-rich PM1 exposure showed higher MT-TF and MT-RNR1 methylation than low-exposed controls (difference = 1.41, P = 0.002); MT-TF and MT-RNR1 methylation was significantly associated with PM1 exposure (beta = 1.35, P = 0.025); and MT-RNR1 methylation was positively correlated with mtDNA copy number (r = 0.36; P = 0.02). D-loop methylation was not associated with PM1 exposure. We found no effects on mtDNA methylation from air benzene (Study 2) and traffic-derived EC exposure (Study 3). CONCLUSIONS: Mitochondrial MT-TF and MT-RNR1 DNA methylation was associated with metal-rich PM1 exposure and mtDNA copy number. Our results suggest that locus-specific mtDNA methylation is correlated to selected exposures and mtDNA damage. Larger studies are needed to validate our observations.

Number size distribution of fine and ultrafine fume particles from various welding processes.

Studies in the field of environmental epidemiology indicate that for the adverse effect of inhaled particles not only particle mass is crucial but also particle size is. Ultrafine particles with diameters below 100 nm are of special interest since these particles have high surface area to mass ratio and have properties which differ from those of larger particles. In this paper, particle size distributions of various welding and joining techniques were measured close to the welding process using a fast mobility particle sizer (FMPS). It turned out that welding processes with high mass emission rates (manual metal arc welding, metal active gas welding, metal inert gas welding, metal inert gas soldering, and laser welding) show mainly agglomerated particles with diameters above 100 nm and only few particles in the size range below 50 nm (10 to 15%). Welding processes with low mass emission rates (tungsten inert gas welding and resistance spot welding) emit predominantly ultrafine particles with diameters well below 100 nm. This finding can be explained by considerably faster agglomeration processes in welding processes with high mass emission rates. Although mass emission is low for tungsten inert gas welding and resistance spot welding, due to the low particle size of the fume, these processes cannot be labeled as toxicologically irrelevant and should be further investigated.

[Metal fume fever, often unrecognized]. / Metaaldampkoorts, vaak niet herkend.

BACKGROUND: Metal fume fever is an occupational disease caused by inhalation of volatile metal oxides. Clinically there is a strong resemblance to influenza. It is thought that metal fume fever occurs much more frequently than it is reported. The symptoms are self-limiting without treatment, disappearing within 24-48 hours without residual symptoms. CASE DESCRIPTION: A male 35-year-old construction worker had cut galvanized steel plates in a closed environment. He had a flu-like illness with fever, leucocytosis and hypoxemia. The symptoms resolved completely without treatment within 18 hours. CONCLUSION: Metal fume fever is a frequently occurring disease but is often overlooked. It is important to ask about exposure to metal fumes in certain occupational groups in order to make the correct diagnosis. In this way measures can be taken to avoid exposure to metal oxides and to prevent recurrence of the disease.

Aorta-to-right ventricular fistula due to pectus bar migration.

A 23-year-old man, operated on for pectus excavatum with a modified Ravitch procedure, was admitted to our emergency department suffering from severe dyspnea. Massive pericardial effusion, rupture of the sinus of Valsalva, and aortic-to-right ventricular fistula were present on echocardiography. Cardiac penetration of the metal bar was detected on chest CT scan. The defect at the right sinus of Valsalva was closed with a PTFE patch, and the right aortic and ventricular ruptures were repaired primarily.

Incomplete left bundle branch block as an artefact caused by the Nuss procedure for pectus excavatum.

AIMS: Nuss procedure is an established and well approved minimally invasive technique for the correction of pectus excavatum. Hereby an individually curved steel bar is inserted to stabilize the thorax. This study aimed to describe ECG changes associated with this procedure. METHODS AND RESULTS: Electrocardiographs of 65 patients who underwent Nuss procedure in our Hospital were evaluated before and after bar implantation as well as after bar removal. In the Goldberger leads, there was a consistent reduction in the QRS amplitude in lead I. In the Wilson leads, the most prominent change was a reduction in the QRS amplitude and a novel r' wave forming a slightly elevated J-point in the left lateral leads. Additionally, we noticed the loss of the former small and physiological q wave in the same leads, typical for an incomplete left bundle branch block (ILBBB). These changes resolved after bar removal. CONCLUSION: We describe the common finding of a reversible incomplete ILBBB after Nuss surgery. The reason for these ECG changes remain unclear. Since cardiac ischaemia, damage, or perioperative irritation of the pericardium is improbable and the alteration of the anatomic thoracic situation remains after bar explantation, we suspect an artefact through alteration of the electric field by the steel bar. Practitioners dealing with patients after Nuss procedure should be aware of this most probably harmless finding.