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Abstract As one of the main occupational hazards, welding fumes can cause oxidative damage and induce series of diseases, such as COPD or asthma. To clarify the effects of the metal fume ultrafine particulates (MF-UFPs) of welding fumes on oxidative damage, UFPs were collected by melt inert gas (MIG) and manual metal arc (MMA) welding, and the composition was confirmed. Human bronchial epithelial 16HBE cells were treated with 0–1000 µg/cm2 MF-UFPs to analyse the cytotoxicity, oxidative stress and cytokines. The protein and mRNA expression of Keap1-Nrf-2/antioxidant response elements (AREs) signalling pathway components were also analysed. After 4 h of treatment, the cell viability decreased 25% after 33.85 and 32.81 µg/cm2 MIG/MMA-UFPs treated. The intracellular ATP concentrations were also decreased significantly, while LDH leakage was increased. The decreased mitochondrial membrane potential and increased ROS suggested the occurrence of oxidative damage, and the results of proteome profiling arrays also showed a significant increase in IL-6 and IL-8. The expression of AREs which related to antioxidant and anti-inflammatory were also increased. These results indicate that the MF-UFPs can cause oxidative stress in 16HBE cells and activate the Nrf-2/ARE signalling pathway to against oxidative damage.

Manual welding operations are performed inside the engine room of a liquefied natural gas carrier under construction. The welders are at risk of exposure to welding fumes in case of poor ventilation. Therefore, ventilation fans are installed at shipbuilding sites to improve indoor air quality. Although ensuring the respiratory health of welders is important, studies focusing on ventilation in the ship engine room have not been conducted. Therefore, the ventilation efficiency was evaluated herein based on the placement of ventilation fans to alleviate air stagnation using a computational fluid dynamic (CFD) model operating on Fluent. The mean age of air (MAA) was computed to assess the ventilation efficiency. In addition, particles with size and physical properties similar to welding fumes were sourced assuming 30 welders in the engine room. Results revealed that ventilation fan and/or exhaust in enclosed spaces contributes significantly to alleviating the MAA level. MAA and particle distribution did not correlate well due to the different properties of air and the iron oxide particle. Therefore, to determine the optimal ventilation fan displacement, particle motion should be studied along with performing MAA analysis. The proposed CFD model potentially guides to improvement of the working environments and respiratory health of welders.

Manual welding operations are performed inside the engine room of a liquefied natural gas carrier under construction. The welders are at risk of exposure to welding fumes in case of poor ventilation. Therefore, ventilation fans are installed at shipbuilding sites to improve indoor air quality. Although ensuring the respiratory health of welders is important, studies focusing on ventilation in the ship engine room have not been conducted. Therefore, the ventilation efficiency was evaluated herein based on the placement of ventilation fans to alleviate air stagnation using a computational fluid dynamic (CFD) model operating on Fluent. The mean age of air (MAA) was computed to assess the ventilation efficiency. In addition, particles with size and physical properties similar to welding fumes were sourced assuming 30 welders in the engine room. Results revealed that ventilation fan and/or exhaust in enclosed spaces contributes significantly to alleviating the MAA level. MAA and particle distribution did not correlate well due to the different properties of air and the iron oxide particle. Therefore, to determine the optimal ventilation fan displacement, particle motion should be studied along with performing MAA analysis. The proposed CFD model potentially guides to improvement of the working environments and respiratory health of welders. [ABSTRACT FROM AUTHOR]

Background: This study seeks to define the pulmonary function of a considerably large group in one of the largest automotive companies in Iran. The aim of this study was to compare the two groups of spot-welding (exposed) and assembly line (unexposed) workers in terms of pulmonary function and conclude the probable impacts of metal fumes on pulmonary function in the two groups. Methods: A total of 1,798 spot-welding personnel and 2,160 assembly line personnel were compared in terms of pulmonary function. Moreover, 120 breathing zone samples were collected from the welders' metal fumes and were analyzed. The parameters of age, anthropometric indices, smoking, and pulmonary symptoms were also compared with across the two groups. Results: Results revealed the FEV1 mean of the total population to be 3.9 ± 0.5 liters and FVC to have been 4.9 ± 0.7 liters. Besides, predicted FEV1 and FVC percentages across the whole population were close to 100%, suggesting the better condition of the studied population compared with normal individuals in the society. All the parameters of age, weight, height, and smoking status were similar in the two groups, and no statistically significant difference was observed between the two groups in terms of pulmonary functions. Conclusion: Implementation of professional health and health improvement programs, running screening programs, and hiring personnel with no history of mild pulmonary disorders, and healthy workers effect at the recruitment stage could be the reasons behind the lack of significant difference between the two exposed and unexposed groups to metal fumes in the automotive industry in terms of pulmonary function. [ABSTRACT FROM AUTHOR]

In this study a paper-based analytical device was developed using screen printing technique for the determination of particulate iron from welding fumes. The operational parameters such as volume and concentration of 1,10-phenanthroline, volume and concentration of hydroxylamine were optimized by the Box Behnken Design (BBD) using Minitab. Additionally, the μ-PAD's sample solution holding capacity and reaction time were also optimized. Under the optimized condition, particulate metal concentrations were colorimetrically quantified using a handheld mobile phone and image processing software, ImageJ. Very good analytical performance such as good linearity of the calibration curve and better selectivity was observed by the developed method. The limit of detection for Fe3+ assay was 4.6 mg/L; which is adequate to determine the threshold concentration limit of particulate iron set by the regulatory bodies (6 mg/L). The μ-PAD revealed 95-99% recovery compared with the UV-Vis spectrophotometry (98-100%). Furthermore, welding fume samples were collected in Addis Ababa over five days, using mixed cellulose ester filters and the findings show a high concentration that exceeds the standard levels. Analyzing particulate iron with μ-PADs yielded results consistent with UV-Vis spectrophotometry, suggesting μ- PADs' potential application for occupational particulate iron exposure measurement, eliminating the need for expensive analytical devices. [ABSTRACT FROM AUTHOR]

Abstract Background Exposure to welding fumes can lead to different respiratory health disorders, including lung cancer, due to long-term exposures. In Ethiopia, large numbers of people are engaged in the welding sector. Often, these workers are exposed to welding fumes at their workplaces, however, the level of exposure and its health effects have never been studied. Objective To measure the level of personal welding fume exposure and assess chronic respiratory symptoms and associated factors, among micro and small-scale enterprise metal workshop workers, in Akaki Kality Sub city, Ethiopia. Methods A comparative cross-sectional study involving 226 welders and 217 controls. Chronic respiratory symptoms were assessed using a standardized questionnaire adopted from the American Thoracic Society (ATS). Welding fumes were collected from the welder’s breathing zone using 37 mm close-faced plastic cassettes fitted with Polyvinyl Chloride (PVC) filters connected to Casella pumps at an airflow rate of 2 L/min. Result The overall prevalence of chronic respiratory symptoms among welders and controls were 54 (23.9%) and 20 (9.2%) respectively. The geometric mean and geometric standard deviation (GSD) of personal welding fume exposure, among welders was 5.98 mg/m3 (± GSD = 1.54). In this study, 53.3% of the samples exceeded the Occupational Exposure Limit defined by the American Conference of Governmental Industrial Hygiene. Chronic respiratory symptoms were significantly associated with educational status (Adjusted Odds Ratio (AOR): 5.11, 95% CI: 1.35, 19.33), respiratory protective equipment use (AOR: 3.33, 95% CI: 1.52, 7.31), safety training (AOR: 2.41, 95% CI: 1.10, 5.28), smoking (AOR:3.57, 95% CI: 1.54, 8.23), welding machine maintenance (AOR: 1.87, 95% CI: 1.01, 3.59) and welding site (i.e. indoors vs. outdoor) (AOR: 6.85. 95% CI: 2.36, 19.89). Conclusions The prevalence of chronic respiratory symptoms among welding workers was significantly higher than controls. More than half of the samples exceeded the Occupational Exposure Limit. Educational status, implementation of safety training, and welding sites were significantly associated with chronic respiratory symptoms. The results suggested a need to reduce welding fume exposure to improve the respiratory health of the workers.

Aluminum alloy is crucial for lightweight and fuel-efficient vehicles due to its strength, lightness, and corrosion resistance. However, welding aluminum vehicle parts poses challenges, particularly porosity issues caused by trapped hydrogen gas in the weld metal. This study aimed to investigate the impact of the welding room environment on the health and properties of aluminum welding joints. To achieve this, an isolated room was created, where variations in airflow velocity (1.1 m/s, 1.6 m/s, and 2.1 m/s) and temperature (19 °C, 27 °C, and 35 °C) were implemented. The fume condition of the room was assessed to determine its impact on health aspects, while bead appearance and macrostructure were evaluated to assess weld joint quality. Results revealed that higher airflow velocity and temperature reduced fume concentration in the welding room, indicating a healthier environment. However, these conditions also led to increased porosity defects and influenced the performance of the shielding gas. Additionally, higher ambient temperatures increased hydrogen solubility in the molten aluminum, exacerbating porosity issues. For optimal welder comfort and high-quality weld joints, it is recommended to maintain a low temperature and airflow velocity in the welding room, ensuring a healthier working environment while minimizing porosity defects. [ABSTRACT FROM AUTHOR]

Fume morphology is the science of the structures, forms, shapes, fractions, and chemical composition of particles [...]

Welding fume is a common exposure in occupational settings. Gravimetric analysis for total particulate matter is common; however, the cost of laboratory analyses limits the availability of quantitative exposure assessment for welding fume metal constituents in occupational settings. We investigated whether a field portable X-ray fluorescence spectrometer (FP-XRF) could provide accurate estimates of personal exposures to metals common in welding fume (chromium, copper, manganese, nickel, vanadium, and zinc). The FP-XRF requires less training and is easier to deploy in many settings than traditional wet laboratory analyses. Filters were analyzed both by FP-XRF and inductively coupled plasma mass spectrometry (ICP-MS). We estimated the FP-XRF limit of detection for each metal and developed a correction factor accounting for the non-uniform deposition pattern on filter samples collected with an Institute of Medicine (IOM) inhalable particulate matter sampler. Strong linear correlation was observed for all metals (0.72

The present study discusses the effect of the addition of nano-sized arc stabilizing materials on fume emissions and its solubility characteristics. Micro and nano-sized sodium/potassium titanates were added to the SMAW electrode flux as a substitute for the conventional sodium and potassium silicate compounds. The total and soluble metal concentration of fumes from the newly developed electrodes were estimated and compared with that of commercially available electrodes. The estimation of fume formation rate and breathing zone concentration of fumes followed the ISO 15011–1 and ISO 10882–1 standard. An average 50% reduction in the soluble fraction of fumes was observed from the electrodes containing micro-sized potassium-titanate compounds, and the reduction was further improved by 60% when nano-sodium titanate was added to the flux. Whereas, the reduction in soluble metal concentration for potassium titanate coated electrodes were 45% and 55%, in that order, for their micro and nano-structured forms. The soluble fraction of hexavalent chromium from the electrodes containing 100% nano sodium/potassium titanates was reduced up to 50% in each impactor stage. The inclusion of nano-sized sodium titanate in the flux resulted in a reduction in fume formation rate up to 55% and breathing zone concentration of fumes by 58% compared to the conventional sodium silicate coated electrodes. The electrode assaying 100% nano-potassium titanate showed a reduction of 59% in fume formation rate and 61% in breathing zone concentration compared to that of conventional potassium silicate-coated electrodes. [ABSTRACT FROM AUTHOR]

Objective: Welding fume exposure is inevitable of welding workers and poses a severe hazard to their health since welding is a necessary industrial process. Thus, preclinical diagnostic symptoms of worker exposure are of great importance. The aim of this study was to screen serum differential metabolites of welding fume exposure based on UPLC–QTOF-MS/MS. Methods: In 2019, 49 participants were recruited at a machinery manufacturing factory. The non-target metabolomics technique was used to clarify serum metabolic signatures in people exposed to welding fume. Differential metabolites were screened by OPLS-DA analysis and Student's t-test. The receiver operating characteristic curve evaluated the discriminatory power of differential metabolites. And the correlations between differential metabolites and metal concentrations in urine and whole blood were analyzed utilizing Pearson correlation analysis. Results: Thirty metabolites were increased significantly, and 5 metabolites were decreased. The differential metabolites are mainly enriched in the metabolism of arachidonic acid, glycero phospholipid, linoleic acid, and thiamine. These results observed that lysophosphatidylcholine (20:1/0:0) and phosphatidylglycerol(PGF1α/16:0) had a tremendous anticipating power with relatively increased AUC values (AUC > 0.9), and they also presented a significant correlation of Mo concentrations in whole blood and Cu concentrations in urine, respectively. Conclusion: The serum metabolism was changed significantly after exposure to welding fume. Lysophosphatidylcholine (20:1/0:0) and phosphatidylglycerol (PGF1α/16:0) may be a potential biological mediator and biomarker for laborers exposure to welding fume. [ABSTRACT FROM AUTHOR]

Welding fume is generated during welding activities and is a known cancer-causing hazard for those working in the welding industry. Worker exposure has been shown to regularly exceed the applicable workplace exposure standard, and control measures are required to reduce worker exposure. The aim of this study is to compare the effectiveness of control measures to prevent welding fume exposure to workers. To achieve this aim, three common welding fume control measures (local exhaust ventilation (LEV), powered air purifying respirators (PAPRs) and on-gun extraction) were used during four different welding tasks. Compared to using no controls, LEV hood capture is likely to reduce welding fume concentrations in the breathing zone of a welder by up to a factor of 9. The use of on-gun LEV is likely to reduce welding fume concentrations in the breathing zone of a welder by up to a factor of 12. The 5th percentile effective protection factors of the PAPR for all sampled welding activities were considerably greater than the required minimum protection factor of 50 specified in AS/NZS 1715:2009 for powered air purifying respirators (PAPRs) with class PAPR-P3 particulate filters with any head covering. [ABSTRACT FROM AUTHOR]

Objective To explore the relationship between occupational exposure to welding fumes and chronic obstructive pulmonary disease (COPD). Methods Literature on welding fumes and COPD from databases until 2022 was retrieved, including PubMed, Springer, China Knowledge Network, Wanfang, etc. The quality of articles that met the criteria was evaluated using the Health Research and Quality (AHRQ) scale. The heterogeneity of articles was judged according to I2 and P values, and the corresponding effect model was selected. The stability of research results was tested by sensitivity analysis; Begg's and Egger's tests were used to evaluate publication bias. Results A total of 108 relevant articles were retrieved, and 11 studies, including 2 cohort studies and 6 cross -sectional studies, were finally included in this meta - analysis. There were 3 425 COPD patients who had not been exposed to welding fumes and 193 COPD patients who had been exposed to welding fumes. The quality scores of the articles were all above 5 points. The heterogeneity among studies was low (I2 = 11.8%), and a fixed-effect model was used to analyze the combined odds ratio (OR). The combined OR value showed that exposure to welding fumes would increase the risk of COPD (OR = 1.39, 95%CI: 1.15-1.69), which still showed that exposure to welding fumes would increase the risk of COPD after controlling for the smoking factor (OR = 1.34, 95% CI: 1.10 -1.63). Sensitivity analysis confirmed that the results of this study were stable. Conclusions Occupational exposure to welding fumes can increase the risk of COPD in occupational populations. Attention should be paid to the health monitoring of workers exposed to welding fumes, early control of possible conditions, and regular followup after leaving their posts. [ABSTRACT FROM AUTHOR]

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OBJECTIVE: This study investigated time trends in occupational exposure to various chemicals in Sweden and the distribution across demographic and labor market sectors. METHODS: Exposure to six chemicals was investigated from 1980 to 2013 by application of a job exposure matrix to national population registers. Respirable crystalline silica (RCS), diesel engine exhaust, welding fumes, wood dust, chlorinated hydrocarbon solvents, and lead were selected to represent different groups of chemicals. Trends in exposure prevalence were investigated by linear regression and compared to the occupationally active population. Confidence intervals for the rate of change over time were obtained by bootstrapping. RESULTS: The proportion of workers born outside the Nordic countries increased over time in those exposed to RCS, diesel exhaust and wood dust. There was a shift of exposed jobs to small companies (

Occupational exposure to contaminants created by electronic manufacturing process is not well characterized. The aim of this study was to carry out risk assessments of exposure to welding fume and airborne heavy metals (HMs) in electronic manufacturing workshops. Seventy-six air samples were collected from five sites in Hangzhou, China. In welding workshops, the most abundant contaminant found was welding fume, followed by Fe, Mn, Zn, Cu, Pb, Cd, and Cr. The concentration of Mn was positively correlated with Fe (r = 0.906). When compared with non-welding workshops, the Fe content in the air of welding workshops increased significantly (P < 0.05), while the Cu content decreased significantly (P < 0.05). Singapore semi-quantitative health risk assessment model and the United States Environmental Protection Agency (US EPA) inhalation risk assessment model were applied to assess the occupational exposure. In welding workshops, the levels of 8-h time weighted average (8 h-TWA) calculated for welding fume (range 0.288 ~ 6.281 mg/m3), Mn (range Nd ~ 0.829 mg/m3), and Fe (range 0.027 ~ 2.234 mg/m3) partly exceeded the permissible limits. While, in non-welding workshops, the average of 8 h-TWA for Cu (0.411 mg/m3) was higher than the limit. The risk rates (RR) assessed for Pb (2.4 vs 1.7), Mn (2.0 vs 1.4), and Fe (1.4 vs 1.0) were higher in welding workshops than that in non-welding workshops, but Cu (1.0 vs 2.2) were lower. The mean excess lifetime cancer risks (ELCR) in welding (5.59E − 06 per 1000 people) and non-welding (1.88E − 06 per 1000 people) workshops were acceptable. The mean non-cancer risk (HQ) estimated for Mn was greater than 10 in both welding (HQ = 164) and non-welding (HQ = 11.1) workshops. These results indicate that there was a risk of occupational exposure implication in the electronic manufacturing workshops. Reducing contaminant exposure through engineering controls and management strategies, such as efficient ventilation and reducing exposure hours, is thus suggested. [ABSTRACT FROM AUTHOR]

Aluminum alloy is crucial for lightweight and fuel-efficient vehicles due to its strength, lightness, and corrosion resistance. However, welding aluminum vehicle parts poses challenges, particularly porosity issues caused by trapped hydrogen gas in the weld metal. This study aimed to investigate the impact of the welding room environment on the health and properties of aluminum welding joints. To achieve this, an isolated room was created, where variations in airflow velocity (1.1 m/s, 1.6 m/s, and 2.1 m/s) and temperature (19 °C, 27 °C, and 35 °C) were implemented. The fume condition of the room was assessed to determine its impact on health aspects, while bead appearance and macrostructure were evaluated to assess weld joint quality. Results revealed that higher airflow velocity and temperature reduced fume concentration in the welding room, indicating a healthier environment. However, these conditions also led to increased porosity defects and influenced the performance of the shielding gas. Additionally, higher ambient temperatures increased hydrogen solubility in the molten aluminum, exacerbating porosity issues. For optimal welder comfort and high-quality weld joints, it is recommended to maintain a low temperature and airflow velocity in the welding room, ensuring a healthier working environment while minimizing porosity defects.

There is an increasing need to evaluate concentrations of nanoparticles in occupational settings due to their potential negative health effects. The Nanoparticle Respiratory Deposition (NRD) personal sampler was developed to collect nanoparticles separately from larger particles in the breathing zone of workers, while simultaneously providing a measure of respirable mass concentration. This study compared concentrations measured with the NRD sampler to those measured with a nano Micro Orifice Uniform-Deposit Impactor (nanoMOUDI) and respirable samplers in three workplaces. The NRD sampler performed well at two out of three locations, where over 90% of metal particles by mass were submicrometer particle size (a heavy vehicle machining and assembly facility and a shooting range). At the heavy vehicle facility, the mean metal mass concentration of particles collected on the diffusion stage of the NRD was 42.5 ± 10.0 µg/m3, within 5% of the nanoMOUDI concentration of 44.4 ± 7.4 µg/m3. At the shooting range, the mass concentration for the diffusion stage of the NRD was 5.9 µg/m3, 28% above the nanoMOUDI concentration of 4.6 µg/m3. In contrast, less favorable results were obtained at an iron foundry, where 95% of metal particles by mass were larger than 1 µm. The accuracy of nanoparticle collection by NRD diffusion stage may have been compromised by high concentrations of coarse particles at the iron foundry, where the NRD collected almost 5-fold more nanoparticle mass compared to the nanoMOUDI on one sampling day and was more than 40% different on other sampling days. The respirable concentrations measured by NRD samplers agreed well with concentrations measured by respirable samplers at all sampling locations. Overall, the NRD sampler accurately measured concentrations of nanoparticles in industrial environments when concentrations of large, coarse mode, particles were low.

Computational fluid dynamics (CFD) is an indispensable simulation tool for predicting the emission of pollutants in the work environment. Welding is one of the most common industrial processes that might expose the operators and surrounding workers to certain hazardous gaseous metal fumes. In the present study, we used computational fluid dynamics (CFD) methodology for simulating the emission of iron fumes from the shielded metal arc welding (SMAW) procedure. A galvanized steel chamber was fabricated to measure the pollutant concentration and identify the size of the fume created by the SMAW. Then, the emission of welding aerosol was simulated using a method of computational fluid-particle dynamics with the ANSYS 2020 R1 software. The highest amount of welding fumes concentration was related to iron fumes (i.e., 3045 μg/m3 with a diameter of 0.25 μm). The results of the current study indicated that the local exhaust and general ventilation system can prevent the spreading of welding fumes to the welder's breathing zone and the surrounding environment. CFD was also found to be an efficient method for predicting the emission of the iron fumes created by SMAW as well as for selecting an appropriate ventilation system. However, further studies that take the modeling of welding-generated emission of additional metal particles and gases into account will need to be undertaken. [ABSTRACT FROM AUTHOR]

Objectives: The mask fit test confirms whether the wearing condition of the wearer's face and the facepiece of the respirators are used appropriately. This study aimed to examine whether the results of the mask fit test affect the association between the concentration of metals related to welding fumes in biological samples and the results of time‐weighted average (TWA) personal exposures. Methods: A total of 94 male welders were recruited. Blood and urine samples were obtained from all participants to measure the metal exposure levels. Using personal exposure measurements, the 8‐h TWA (8 h‐TWA) of respirable dust, TWA of respirable Mn, and 8‐h TWA of respirable Mn were calculated. The mask fit test was performed using the quantitative method specified in the Japanese Industrial Standard T8150:2021. Results: Fifty‐four participants (57%) passed the mask fit test. Only in the Fail group of the mask fit test, it was observed that blood Mn concentrations be positively associated with the results of TWA personal exposure after adjusting for multivariate factors (8‐h TWA of respirable dust; coefficient, 0.066; standard error (SE), 0.028; P = 0.018, TWA of respirable Mn: coefficient, 0.048; SE, 0.020; P = 0.019, 8 h‐TWA of respirable Mn: coefficient, 0.041; SE, 0.020; P = 0.041). Conclusions: The results clarify that welders with high concentrations of welding fumes in their breathing air zone are exposed to dust and Mn if there is leaking air owing to the lack of fitness between respirators and the wearer's face when using human samples in Japan. [ABSTRACT FROM AUTHOR]

Objective This study investigated time trends in occupational exposure to various chemicals in Sweden and the distribution across demographic and labor market sectors. Methods Exposure to six chemicals was investigated from 1980 to 2013 by application of a job exposure matrix to national population registers. Respirable crystalline silica (RCS), diesel engine exhaust, welding fumes, wood dust, chlorinated hydrocarbon solvents, and lead were selected to represent different groups of chemicals. Trends in exposure prevalence were investigated by linear regression and compared to the occupationally active population. Confidence intervals for the rate of change over time were obtained by bootstrapping. Results The proportion of workers born outside the Nordic countries increased over time in those exposed to RCS, diesel exhaust and wood dust. There was a shift of exposed jobs to small companies (<50 employees), especially for RCS, welding fumes, wood dust, and chlorinated hydrocarbon solvents. For RCS and welding fumes, there was a marked drop in exposure levels from 1980 to 1990 but small changes thereafter. Exposure to lead diminished, both in terms of prevalence and intensity. Conclusions Over time, several exposures tended to shift to small companies, the construction sector, and migrant workers, all factors being indicative of less well-controlled working conditions. Occupational exposure to chlorinated organic solvents and lead diminished, while exposure levels to RCS and welding fumes have changed little since 1990. In view of the serious and well-established negative health effects, increased efforts to reduce exposure to RCS and welding fumes are needed. [ABSTRACT FROM AUTHOR]

This paper presents the influence of synthetic rutile addition to the electrode flux on the shielded metal arc welding emissions. A systematic study was conducted by modifying the electrode flux composition with synthetic and conventional rutile combinations. The fume particulates emitted during welding were sampled using an AWS F1.2 standard fume test chamber, and its concentration was determined through gravimetric analysis. Online monitoring of arc stability, droplet transfer characteristics, and spatter formations was performed using digital storage oscilloscope, high-speed camera, and infrared camera devices, respectively. The UVC and ozone concentrations in the arc atmosphere were also measured using standard procedures. The results revealed that the addition of synthetic rutile up to 50% could reduce the fume emissions by as much as 31.4% compared to the conventional electrode. The present study also focused on the reduction of hexavalent chromium (Cr(VI)), a hazardous and carcinogenic chemical species in welding fumes. In order to achieve a combined reduction in the concentration of hexavalent chromium and fume, Zn, a reactive metal, was added to the electrode flux of the experimental electrodes. The primary mechanism of reduction in fumes and Cr(VI) concentration was recognized from the study as the decrease in the surface tension of the pendent liquid droplet ensued by the presence of fine-grained TiO2 in the synthetic rutile. Apart from lowering fume emissions, the experimental electrodes achieved a deposition efficiency of up to 61.9%, which was appreciably higher than that of the conventional electrode. [ABSTRACT FROM AUTHOR]

Welding fume is generated during welding activities and is a known cancer-causing hazard for those working in the welding industry. Worker exposure has been shown to regularly exceed the applicable workplace exposure standard, and control measures are required to reduce worker exposure. The aim of this study is to compare the effectiveness of control measures to prevent welding fume exposure to workers. To achieve this aim, three common welding fume control measures (local exhaust ventilation (LEV), powered air purifying respirators (PAPRs) and on-gun extraction) were used during four different welding tasks. Compared to using no controls, LEV hood capture is likely to reduce welding fume concentrations in the breathing zone of a welder by up to a factor of 9. The use of on-gun LEV is likely to reduce welding fume concentrations in the breathing zone of a welder by up to a factor of 12. The 5th percentile effective protection factors of the PAPR for all sampled welding activities were considerably greater than the required minimum protection factor of 50 specified in AS/NZS 1715:2009 for powered air purifying respirators (PAPRs) with class PAPR-P3 particulate filters with any head covering.

The most important welding processes used are the gas metal arc (GMA) welding, the tungsten inert gas (TIG) welding, and the manual metal arc (MMA) welding processes. The goal of our investigation was to monitor the distribution of iron (Fe), manganese (Mn), calcium (Ca), and magnesium (Mg) in the lung, spleen, liver, and kidney of mice after inhalation exposure of different welding methods using different steel base materials. The treatment groups were the following: MMA-mild steel, MMA-molybdenum-manganese (MoMn) alloy, TIG-mild steel, and TIG-stainless steel. The samples were taken 24 and 96 h after the treatments. Most importantly, it was found that the Mn concentration in the lung' samples of the MMA-mild steel and the MMA-MoMn groups was increased extremely at both sampling times and in the spleen' samples also. In the TIG groups, the rise of the Mn concentration was only considerable in the lungs and spleens at 24 h, and emerged concentration was found in the liver in 96 h samples. Histopathology demonstrated emerged siderin content in the spleens of the treated animals and in siderin filled macrophages in the lungs mostly in all treated groups. Traces of high-level glycogen retention was found in the MMA groups at both sampling times. Similar glycogen retention in TIG-Ms and TIG stainless group's liver samples and emerged number of vacuoles, especially in the hepatocytes of the TIG-stainless steel 96 h group were also found. The mentioned results raise the consequence that there is a considerable difference in the kinetics of the Mn distribution between the MMA- and the TIG-fume–treated groups. Hence, the result suggests that manganese has a particle-size–dependent toxico-kinetics property. The anomaly of the glycogen metabolism indicates the systemic effect of the welding fumes. Also, the numerous vacuoles mentioned above show a possible liver-specific adverse effect of some components of the TIG-stainless steel welding fumes. [ABSTRACT FROM AUTHOR]

The aim of this part of the article is to substantiate the order of procedures for determining the hygienic characteristics of welding materials in accordance with the International Standards of ISO 15011 series and, accordingly, with the harmonized National DSTU ISO 15011. The essence of the problem of correct comparative hygienic evaluation of welding materials by improving the procedure of studying indices of the levels of emissions and chemical composition of welding fumes applying the standards of DSTU ISO 15011. The features of basic procedures of hygienic evaluation of welding materials, their specifics and order, as well as the main indices used for its performance are presented. [ABSTRACT FROM AUTHOR]

OBJECTIVE: This study investigated whether low-to-moderate exposure to welding fumes is associated with adverse effects on the cardiovascular system. METHODS: To test this, we performed a longitudinal analysis of 78 mild steel welders and 96 controls; these subjects were examined twice, six years apart (ie, timepoints 1 and 2). All subjects (male and non-smoking at recruitment) completed questionnaires describing their health, work history, and lifestyle. We measured their blood pressure, endothelial function (by EndoPAT), and risk markers for cardiovascular disease [low-density lioprotein (LDL), homocysteine, C-reactive protein]. Exposure to welding fumes was assessed from the responses to questionnaires and measurements of respirable dust in their breathing zones adjusted for use of respiratory protection equipment. Linear mixed-effect regression models were used for the longitudinal analysis. RESULTS: Median respirable dust concentrations, adjusted for respirable protection, of the welders were 0.7 (5–95 percentile range 0.2–4.2) and 0.5 (0.1–1.9) mg/m^3 at timepoints 1 and 2, respectively. Over the six-year period, welders showed a statistically significant increase in systolic [5.11 mm Hg, 95% confidence interval (CI) 1.92–8.31] and diastolic (3.12 mm Hg, 95% CI 0.74–5.5) blood pressure compared with controls (multi-variable adjusted mixed effect models). Diastolic blood pressure increased non-significantly by 0.22 mm Hg (95% CI -0.02–0.45) with every additional year of welding work. No consistent significant associations were found between exposure and endothelial function, LDL, homocysteine, or C-reactive protein. CONCLUSION: Exposure to welding fumes at low-to-moderate levels is associated with increased blood pressure, suggesting that reducing the occupational exposure limit (2.5 mg/m^3 for inorganic respirable dust in Sweden) is needed to protect cardiovascular health of workers.

Objectives Workplace measurements in the past have shown that the applicable occupational exposure limits (OELs) are regularly exceeded in practice when high-emission welding processes are applied. The InterWeld pilot study was planned as part of an intervention study to show under which conditions compliance with the OEL is achievable in gas metal arc welding (GMAW) with solid wire. The investigation focussed on local exhaust ventilation, i.e. captor hoods and welding torches with integrated fume extraction. Methods Forty tests with hand-guided GMAW were configured by experts with regard to all technical parameters and carried out by a professional welder. Effects of protective measures and process parameters on the exposure to respirable welding fumes and airborne manganese (Mn), chromium, nickel, and hexavalent chromium were investigated. Personal sampling was carried out in the welder's breathing zone outside the face shield at high flow rates (10 l min−1) in order to achieve sufficient filter loading. Particle masses and welding fume concentrations were determined by weighing the sampling filters. Metal concentrations were analysed by inductive coupled plasma mass spectrometry. In order to evaluate the effects on exposure, the measurements were performed under similar conditions. The data were analysed descriptively and with mixed linear models. For measurements below the limit of detection, the exposure level was estimated using multiple imputation. Results Two to five times higher exposures to respirable welding fumes and airborne metals were observed during welding of 10 mm sheets than during welding of 2- or 3-mm sheets. Welding fume and Mn exposure were reduced by 70 and 90% when on-torch extraction or a captor hood was applied. Other airborne metals were reduced to a similar extent. Modifications on welding parameters led to a reduction of exposure against respirable particles by 51 up to 54%. Conclusions Although proper extraction at the point of origin and lower-emitting process variants ensure a drastic reduction in exposure, compliance with current OELs is not guaranteed. In order to ensure adequate health protection, especially at workplaces where thick sheets with long relative arc times are processed, there is a need for technical development. [ABSTRACT FROM AUTHOR]

The aim of the article was to elaborate a single system of hygienic evaluation of welding materials in accordance with the standards of DSTU ISO 15011 series and justify the appropriateness of its application. The essence of the problem of a correct comparative hygienic evaluation of domestic and foreign welding materials is explained. The methods of improvement of the procedure of studying indices of levels of emissions and chemical composition of welding fumes due to the application of DSTU ISO 15011 standards are presented. The scope of the requirements of each of the standards of the specified series is characterized. The main procedures of hygienic evaluation of welding materials, their specifics and sequence, as well as the main indices, based on which it is carried out, are highlighted. [ABSTRACT FROM AUTHOR]

Introduction and purpose: Risk assessment of toxic or hazardous chemicals enables industrial hygienists to make appropriate decisions regarding management provisions in a healthy workplace. Exposure to total fumes and manganese during welding can have harmful effects on welders’ health. Therefore, the present study was conducted in the metal industry to evaluate the concentration and determine the risk of welders’ exposure to total fumes and manganese in 2018. Methods: In this descriptive-analytical and cross-sectional study, welding fumes were sampled in the breathing zone of 35 welders using filters and cyclones moreover, the concentration of fumes was determined by a weight method. The samples were analyzed according to NIOSH 7301 method using an Inductively Coupled Plasma-Optical Emission Spectrometry to determine the manganese concentration in the fume. Moreover, health exposure risk assessment of workers exposed to welding fumes was performed using the recommended method by the Singapore Health and Safety Association method. The data were analyzed in MINITAB software (version 17). A p-value less than 0.05 was considered statistically significant. Results: The mean concentrations of total fumes and manganese produced in Shielded Metal Arc were 9.56±1.67 and 0.45±0.08 mg/m-3, respectively. These values are about 2 and 22 times higher than the recommended occupational threshold limit for total fumes and manganese according to the American Conference of Governmental Industrial Hygienists, respectively. The risk assessment results showed that the mean values of exposure to total and manganese fume for the welders were moderate and high, respectively. Conclusion: Due to the high level of welders’ exposure to manganese during welding in the metal industry, preventive measures, such as engineering and management control techniques are recommended to reduce exposure to these fumes.

Objective: To explore the bioaccessibility of the main metal components in welding fume welding fume in simulated lung fluid, and to evaluate the exposure level of each metal component in combination with the EPA inhalation exposure risk assessment model. Methods: In November 2022, the microscopic morphology characteristics of welding fumes were analyzed by scanning electron microscopy, the bioaccessibility of each metal component in lung fluid simulated normal and lung inflammatory states was analyzed by in vitro simulation method, and the exposure level of each metal component was calculated in combination with the EPA inhalation exposure risk assessment model. Results: The main metal components in carbon dioxide gas shielded welding fumes were Fe, Mn, Zn, Ti, Al, Cu, Cr, Cd, Ni and As, and the bioaccessibility in simulated normal lung interstitial fluid was 0.82%-1.84%, 5.07%-9.41%, 4.52%-7.23%, 5.10%-8.67%, 20.48%-29.60%, 5.27%-9.83%, 4.80%-7.56%, 0.07%-1.08%, 6.48%-13.84% and 33.02%-42.81%. The bioaccessibility of the above metal components in the lung fluid under simulated lung inflammation was 14.79%-27.45%, 34.53%-46.11%, 35.31%-59.13%, 16.45%-22.51%, 60.78%-76.51%, 26.58%-34.12%, 15.32%-25.87%, 2.0%-5.7%, 34.77%-43.33% and 71.34%-88.36%, respectively. Compared with the simulated lurg interstitial fluid, the bioaccessibility of metal components in the lung fluid under the simulated inflammatory state was increased, and the difference was statistically significant ( P <0.05). The average daily exposure dose Mn in the two simulated lung fluids exceeded the inhalation reference limit (>50 times), and the average daily exposure dose Ti and Cr in the simulated lung inflammation exceeded the reference limit (>1.3 times) . Conclusion: Attention should be paid to the bioaccessibility characteristics of metal components in the exposure level and hazard assessment of welding fumes.

The lowering of the German occupational exposure limit from 3 mg/m3 to 1.25 mg/m3 by 2018 and the high health hazard from tubular cored electrodes shows the need to determine and minimize the emission potential of such wires. With the background knowledge that 95 % of the emitted welding fumes are caused by the filler metal, the possibility to reduce the emission potential at the source of origin is the best opportunity. The objective of the described research project was to reduce the fumes emitted by tubular cored wires without decreasing their economic benefits. Customary cored wires were investigated as well as design features of the wires were detected to optimize them. The selection and adaptation of the filler metal was carried out in cooperation with the manufacturers within their specifications. The technology and basis for the determination of the fume emission rates forms the DIN EN ISO 15011–1:2017. As a first step, the influence of the wire geometry and the filling type was investigated. Two exemplary results are that metal powder electrodes produced three times higher emission rates than rutile cored wires and that the wire geometry has an influence of 40 % on the emission potential. Afterwards, selected tubular cored wires were studied with the objective to figure out the influence of various process parameters. Such as arc voltage, contact tip work distance and shielding gas composition. One result was that the metal-cored wire responded with the highest changes in emission potential when the welding parameter changed. The investigation showed that the health hazard of tubular cored wires is dependent on their design and the process characteristics. Therefore, the hazard classifications of cored wires, e.g. the German TRGS 528 should be rethought. Furthermore, a good comparison of emission rates from different authors without a defined filter type is very difficult. [ABSTRACT FROM AUTHOR]

Welders have an increased risk for cardiovascular disease (CVD) following exposure to welding fumes. The underlying mechanisms are largely unknown; however, oxidative stress, systemic inflammation, and endothelial dysfunction have been suggested as contributing factors to particle-induced CVD. We investigated effects of mild steel welding fume (MSWF) on three target cell types: macrophages, pulmonary epithelial, and vascular endothelial cells. Cells were exposed to MSWF at nontoxic doses for 6 h/day, for five consecutive days. The expression of 40 genes involved in inflammation, fibrosis, and endothelial activation was analyzed. Moreover, changes in the reactive oxygen species production and migration capacity of cells were assessed. The expression of matrix metallopeptidase 1 (MMP1) was induced in both epithelial and endothelial cells following repeated exposure to MSWF. Although MMP1 is important in inflammatory responses in vivo, this effect was not concurrent with changes in the inflammatory status, cell proliferation, and migration capacities, nor did it induce oxidative stress in the cells. Thus, repeated exposure with low doses of MSWF was sufficient neither for inducing inflammatory stress in epithelial cells and macrophages nor for endothelial activation, and higher concentrations of MSWF or the nonparticle fraction of MSWF may be critical in causing the increased risk of CVD observed among welders. [ABSTRACT FROM AUTHOR]

Welding, as a process, is a standard manufacturing method used to combine metals and produces complex aerosols of potentially dangerous metal fumes and gases. Welding procedures, the length of contact, and other workplace conditions other than welding gases were the leading causes that affected the welder's health. Welding gas particles all seem to be somewhere around or less than one micrometer in diameter and less than 100 nanometers in diameter. Vapors are present during welding, whether or not a smoke plume is visible. Owing to their small scale, the vapors can infiltrate the alveoli deeply into the respiratory system. This study aimed to determine the elements and gases and their relation with welder health by using FESEM and EDS x-ray technique. The welders from north rumaila (NR)and south rumaila (SR) the oil field (24 people) were selected for this study and by using the disposable mask to capture the welding fume to determine the nanoparticles of toxic elements, and the results show clinical signs for three persons in SR compare with two persons in NR. On the other hand, the presents of chromium, bromine, argon, and cerium in NR, lack in SR. At the same time, vanadium was found in SR and zero in NR. Generally, other elements like aluminum, copper, palladium, magnesium, lanthanum, iron, and vanadium were observed in both NR and SR in different concentrations; after viewing the NR and SR workshop, the notable mistake was the absence of safety equipment like welding fume extractors and other kinds of HEPA filters. [ABSTRACT FROM AUTHOR]

Studies suggest that alterations in circulating factors are a driver of pulmonary-induced cardiovascular dysfunction. To evaluate, if circulating factors effect endothelial function after a pulmonary exposure to welding fumes, an exposure known to induce cardiovascular dysfunction, serum collected from Sprague Dawley rats 24 h after an intratracheal instillation exposure to 2 mg/rat of 2 compositionally distinct metal-rich welding fume particulates (manual metal arc welding using stainless steel electrodes [MMA-SS] or gas metal arc welding using mild steel electrodes [GMA-MS]) or saline was used to test molecular and functional effects of in vitro cultures of primary cardiac microvascular endothelial cells (PCMEs) or ex vivo organ cultures. The welding fumes elicited significant pulmonary injury and inflammation with only minor changes in measured serum antioxidant and cytokine levels. PCME cells were challenged for 4 h with serum collected from exposed rats, and 84 genes related to endothelial function were analyzed. Changes in relative mRNA patterns indicated that serum from rats exposed to MMA-SS, and not GMA-MS or PBS, could influence several functional aspects related to endothelial cells, including cell migration, angiogenesis, inflammation, and vascular function. The predictions were confirmed using a functional in vitro assay (scratch assay) as well as an ex vivo multicellular environment (aortic ring angiogenesis assay), validating the concept that endothelial cells can be used as an effective screening tool of exposed workers for determining bioactivity of altered circulatory factors. Overall, the results indicate that pulmonary MMA-SS fume exposure can cause altered endothelial function systemically via altered circulating factors. [ABSTRACT FROM AUTHOR]

Copper and zinc containing welding fumes are able to induce systemic inflammation in healthy subjects. In this study the no observed effect levels (NOEL) for welding fumes containing either copper or zinc were assessed. Fifteen healthy male volunteers participated in an exposure. Each subject was exposed to two different concentrations of both, copper and zinc containing welding fumes. Exposure was performed in the Aachen Workplace Simulation Lab. The NOEL was found at metal concentrations between 0.2 and 0.3 mg/m³ for copper and between 0.8 and 1.2 mg/m³ for zinc. The NOEL identified in this study was about a factor of 10 higher than the German workplace threshold limit values (TLV). However. TLV in other countries was in the same range or even higher than the NOEL indicating a considerable risk for workers. [ABSTRACT FROM AUTHOR]

Welding fume particles can pose serious health risks because of its nanoscaled size and pulmonary toxicity. The main components of welding fume particles are iron oxides, most of which are easily magnetized in a magnetic field and subject to magnetic attraction. According to this characteristic, we developed a magnetic composite filter composed of a polyester filter and neodymium iron boron (NdFeB) particles to improve the filtering effect on fume particles. The performance parameters of magnetic filter were studied experimentally. At 5 cm/s face velocity, the filtration efficiency and quality factor of magnetic filter #4 were 2.09 times and 1.55 times of those of filter #0 (no NdFeB particles coated), respectively. In the loading process, the particles accumulation did not weaken the magnetic attraction effect. The filtration efficiencies of magnetic and nonmagnetic filters for 600 nm particles increased by 10.53% at 14.65 g/m2 and 8.17% at 14.33 g/m2, respectively. Unlabelled Image • A magnetic composite filter composed of a polyester filter and NdFeB particles is presented. • The magnetic filter can significantly improve the filtration performance on welding fume particles • The particles accumulation on the magnetic filter does not weaken the magnetic attraction effect. [ABSTRACT FROM AUTHOR]

The exposome is the measure of all exposures of an individual in a lifetime and how those exposures relate to health. The goal was to examine an experimental model integrating multiple aspects of the exposome by collecting biological samples during critical life stages of an exposed animal that are applicable to worker populations. Genetic contributions were assessed using strains of male rats with different genetic backgrounds (Fischer-344, Sprague Dawley, and Brown-Norway) maintained on a regular or high-fat diet for 24 weeks. At week 7 during diet maintenance, groups of rats from each strain were exposed to stainless steel welding fume (WF; 20 mg/m3 × 3 h/d × 4 days/week × 5 weeks) or air until week 12, at which time some animals were euthanized. A separate set of rats from each strain were allowed to recover from WF exposure until the end of the 24-week period. Bronchoalveolar lavage fluid and serum were collected at 7, 12, and 24 weeks to assess general health indices. Depending on animal strain, WF exposure and high-fat diet together worsened kidney toxicity as well as altered different serum enzymes and proteins. Diet had minimal interaction with WF exposure for pulmonary toxicity endpoints. Experimental factors of diet, exposure, and strain were all important, depending on the health outcome measured. Exposure had the most significant influence related to pulmonary responses. Strain was the most significant contributor regarding the other health indices examined, indicating that genetic differences possibly drive the exposome effect in each strain. [ABSTRACT FROM AUTHOR]

In this work, a new covered electrode was developed for a SMAW process by the concurrent use of two fume reduction techniques viz; nano-arc stabilizer coating on welding core wire and nano-particle substitution on the welding flux. The experimental core electrode wires were coated with nano-zirconium to improve the electrode's arc stability and reduce the effective oxygen concentration in the arc atmosphere. To further improve the arc stability, size-reduced synthetic rutile was mixed with the electrode flux. Total fume formation from experimental and conventional electrodes was evaluated and compared. Compared to the conventional electrode, the experimental electrode showed an 82 % reduction in fume production and an 85 % reduction in breathing zone concentration. The combined effect of nano zirconia and size-reduced synthetic rutile increased the reactivity of the arc atmosphere and favoured the reduction of inhalable and respirable fume mass concentration by improving arc stability and reducing spatter formation. The experimental electrodes showed a significant reduction in Cr(VI) concentration in fume up to 68 %. The Cr (VI) concentration in the inhalable and respirable fumes was also reduced by 36 % and 52 % in that order. • Experimental electrodes obtained an 82 % reduction in fume formation rate and 85 % reduction in breathing zone concentration. • Constituents such as Fe,Ni,Mn,Mo,and Cr were reduced for inhalable/respirable ranges. • Cr (VI) up to 36 % in the inhalable and 53 % in the respirable range were reduced. • The morphological analysis indicates the respirable and inhalable fume behaviour. [ABSTRACT FROM AUTHOR]

Based on the principles of plasma discharge adsorption, a new technology of fume coil-clarion, fume charge and fume removal was proposed to purify welding fumes. A fume removal device was designed which might track welding fume source am real rime, and parameters of length and spacing of two electrode plates were determined. By the charge calculation and three-dim-tensional eclectic field analysis of plasma electrostatic adsorption device, the moron trajectory and the change law of fume par-icicles in electric field were studied, and COMSOL software was used to simulate and analyze the effects of particle sizes, inlet gas flow rates and biteplate voltages on the addition efficiency of fume particles. The results show that when the interpolate voltage as in the range of kV, while movement rime in the electric field the fumes particle size may achieve rapid and efficient absorption, and resulting in significant purification. [ABSTRACT FROM AUTHOR]

Welding is a major and highly skilled process that its fumes causes serious health hazards, the biological effect of these fumes on health status consists of respiratory disorders and production of systemic oxidative stress. To determine the relationship between antioxidant enzymes and welding fumes, the blood level of two Red blood cell (RBC) enzymes (Superoxide dismutase (SOD), Glutathione peroxidase (GPX) and serum level of TAS of 51 welders were compared with 42 office workers. Measurement of enzymes concentration and activity was done using spectrophotometer. Environmental and personal exposure air samples for total dust and welding fume metals were collected. Significant decreases were observed in Total serum antioxidant status (TAS) levels (8.3%), SOD (8%) and GPX (36.7%) activities. It was also seen that smoking had negative effect on the TAS concentration. It was concluded that exposure to welding fumes could act as a factor initiating oxidative stress chain in the welders body. Welding fumes could affect the RBC antioxidant enzymes by disrupting the homeostasis of oxidant-antioxidant status and induce oxidative stress. This effect can occur even at the standard level of exposure. This oxidative stress may induce many hazardous effects on human health. [ABSTRACT FROM AUTHOR]

The inhalation and the deposition of welding-generated ultrafine particles in welders' respiratory tracts have been linked to severe pulmonary impairments. In the present study, a mobile aerosol lung deposition apparatus (MALDA) was developed and applied to study the respiratory deposition of ultrafine welding fume particles. The MALDA was constructed with a set of physiologically representative human tracheobronchial airway replicas made with high-resolution 3D printers. Ultrafine welding fume particles were generated in a welding fume chamber and delivered to the MALDA. A series of respiratory deposition experiments were carried out using the MALDA to investigate the deposition of ultrafine welding fume particles in different airway generations of the tracheobronchial airways. The results showed that the fractional deposition of ultrafine welding fume particle in the human tracheobronchial airways down to the 9th airway generation could be readily and systematically measured by the MALDA. The estimated cumulative respiratory deposition ranged from approximately 9–31% for ultrafine welding fume particles between 10 and 100 nm in diameter. The results acquired demonstrated that the MALDA developed has the potential to become a useful apparatus in the future to estimate the respiratory deposition of ultrafine particles in real workplaces. [ABSTRACT FROM AUTHOR]

In order to develop effective protection measures and reduce the number of diseases in the welding industry, a detailed study of the mechanism of propagation of welding fumes in the working zone is necessary. The present work investigates the characteristics of fume sedimentation in the working zone during arc welding with various covered industrial electrodes. The influence of covering type (rutile, basic, acid, and rutile-cellulose) on the quantity (number of particles) of РМ0.3...PM10 fractions in fumes is shown. Data on the absolute quantitative prevalence of particles of the smallest measured PM0.3 fraction (PM0.3/PM10 ≫ 75–90%) were obtained. Based on regression analysis, the sedimentation processes of welding fumes were modeled. The shortest forecast period of particles sedimentation is forecast for acid covered electrodes (53 min.), the maximum – for basic covered ones (150 min.). The maximum predicted distance of fumes distribution in space is expected for rutile-cellulose covered electrodes (16 m), the smallest – for rutile covered ones (6 m). The different types of electrodes for arc welding were ranked according to the degree of negative impact of exposure to fumes depending on the duration of their fume emission rate in the air and the propagation distance in the working zone. [ABSTRACT FROM AUTHOR]

Exposures to airborne particles and toxic gases generated by welding fabrication activities will potentially lead to various diseases. Accurate information on the transport and deposition of such aerosols in the respiratory system is critically needed for precise health risk assessments. To address the data demand mentioned above, a multiscale computational fluid-particle dynamics (CFPD) model was developed in this study. Specifically, a virtual fabrication shop was integrated with a virtual human in the numerical model to evaluate the effects of ventilation condition, particle size, and gas species on the lung uptakes of those welding fume particles and gases. Welding fume particle and gases transmission, transport, and deposition have been simulated and analyzed starting from the emission source to the subject-specific human respiratory system via oral inhalation. Spherical iron particles with diameters of 100, 190, and 830 nm were simulated. The transport and absorption of NO x and CO were predicted too. Steady-state inhalation with 11.87 L/min was applied with two different air filter ventilation conditions. The numerical results indicate that the ventilation condition can significantly influence welding gas transport and deposition. The pulmonary gas absorption rate is much higher at poor ventilation conditions. The air-tissue absorption coefficient is another crucial factor that can impact pulmonary gas absorption. The total particle deposition fractions (TDFs) from mouth/nose to generation 6 (G6) are less than 18.0%, and particles mostly deposit in the oral cavity. Regional and local particle deposition data demonstrate that particles tend to enter the two upper lobes more than the other three lobes. In summary, this study paves the way to build a personalized in silico tool based on CFPD models for noninvasive precise health risk assessments associated with different welding activities. • A CFPD based multiscale model is developed for welding fume lung dosimetry estimation. • Welding fume particles tend to enter the two upper lobes more than the other three lobes in the subject-specific respiratory system via mouth inhalation. • Key parameters that can significantly influence welding fume lung dosimetry are determined. [ABSTRACT FROM AUTHOR]