Systematic review and meta-analysis on prevalence, pattern, and factors associated with ocular protection practices among welders in sub-Saharan Africa.

Background: Due to hazardous working conditions, welders are more likely to be exposed to mild to severe eye issues during the welding process. Globally, this issue is a major contributor to vision loss and blindness. One of the most frequent causes of unilateral blindness in the globe is ocular injury. Objective: This review aimed to assess the pooled prevalence of ocular protection practice and associated factors among welders in sub-Saharan Africa. Methods: Databases including PubMed, Scopus, web of Science, Google Scholar, and the African Journals Online were systematically searched for relevant literature. The statistical analysis was performed using STATA data analysis software version 14, while Microsoft Excel was used for data abstraction. We checked publication bias using a funnel plot and Egger and Begg regression tests. A p-value < 0.05 was considered significant, suggesting the presence of presence publication bias. The I2 statistics were used to assess heterogeneity between studies. The study's overall effect was evaluated using the random effects model. Results: From retrieved 2,326 original studies, 17 studies were included in the final pooled prevalence analysis. The overall prevalence of ocular protection practice among small-scale welders in sub-Saharan Africa was 53.71% (95% CI: 42.54, 64.88). Having pre and in-service training [AOR: 4.97, 95% CI: (2.64, 9.36)], having work experience as a welder [AOR: 4.94, 95% CI: (3.24, 7.54)], and having a history of ocular injury [AOR: 2.99, 95% CI: (1.58, 5.66)] were significantly associated with the ocular protection practices. Conclusions: In sub-Saharan African countries, the ocular protection practices among small-scale welders were low. Furthermore, the current meta-analysis found ocular protection practice to be significantly associated with on-the-job training, work experience of welders, and a history of ocular injury in the past year of small-scale welders in sub-Saharan Africa. This review will serve as baseline data for further studies to generate inputs for eye care providers and policymakers to improve good practice levels about ocular protection. Policies should be put in place to ensure all welders use proper personal-protective equipment, and receive regular health training.

Development of implantable electrode based on bioresorbable Mg alloy for tissue welding application.

An implantable electrode based on bioresorbable Mg-Nd-Zn-Zr alloy was developed for next-generation radiofrequency (RF) tissue welding application, aiming to reduce thermal damage and enhance anastomotic strength. The Mg alloy electrode was designed with different structural features of cylindrical surface (CS) and continuous long ring (LR) in the welding area, and the electrothermal simulations were studied by finite element analysis (FEA). Meanwhile, the temperature variation during tissue welding was monitored and the anastomotic strength of welded tissue was assessed by measuring the avulsion force and burst pressure. FEA results showed that the mean temperature in the welding area and the proportion of necrotic tissue were significantly reduced when applying an alternating current of 110 V for 10 s to the LR electrode. In the experiment of tissue welding ex vivo, the maximum and mean temperatures of tissues welded by the LR electrode were also significantly reduced and the anastomotic strength of welded tissue could be obviously improved. Overall, an ideal welding temperature and anastomotic strength which meet the clinical requirement can be obtained after applying the LR electrode, suggesting that Mg-Nd-Zn-Zr alloy with optimal structure design shows great potential to develop implantable electrode for next-generation RF tissue welding application.

Investigating the effect of welding tool length on mechanical strength of welded metallic matrix by molecular dynamics simulation.

The welding process and the properties of welding instruments may improve the mechanical performance of an item. One of these properties is the length of the welding tool. This approach has a substantial effect on the mechanical strength of the metallic matrix. The current study used molecular dynamics modeling and LAMMPS software to evaluate the effect of welding tool length on the mechanical properties of a welded Cu-Ag metallic matrix. This simulation makes use of the Lennard-Jones potential function and the embedded atom model. First, the equilibrium phase of modeled samples was verified by changing the computation of kinetic and total energies. Next, the mechanical properties of the welded matrix were studied using the stated Young's modulus and ultimate strength. The stress-strain curve of samples demonstrated that the mechanical strength of atomic samples increased as the length of the welding tool (penetration depth) increased. Numerically, by increasing the tool penetration depth of Fe tools from 2 Å to 8 Å, Young's modulus and ultimate strength of the matrixes sample increase from 34.360 GPa to 1390.84 MPa to 38.44 GPa and 1510 MPa, respectively. This suggested that the length of the Fe welding tool significantly affected the mechanical properties of the welded metallic matrix. The longer the length of Fe welding tools, the more particles were involved, and consequently, more bonds were formed among the particles. Bonding among the particles caused changes in mechanical properties, such as greater ultimate strength. This method can optimize mechanical structures and be useful in various industries.

[Analysis of disease burden of welder's pneumoconiosis in Jiangsu Province].

Objective: To investigate the current status of disease burden and its influencing factors among welder's pneumoconiosis patients, and provide scientific basis for taking targeted intervention measures. Methods: From June 2022 to June 2023, the patients with welder's pneumoconiosis in Jiangsu Province were selected from 1956 to 2020 as the research objects, and disability adjusted life years (DALY) were used as the comprehensive index to study the disease burden. The direct and indirect economic losses caused by the diseases were calculated, and the factors affecting the disease burden were discussed by multiple linear regression method. Results: A total of 974 cases of welder's pneumoconiosis were reported in Jiangsu Province, the cumulative loss of DALY was 6300.73 person-years, and the per capita loss was 6.47 person-years. Among them, the healthy life years lost due to disability (YLD) was 6156.50 person-years (97.71%) , and the healthy life years lost due to premature death (YLL) was 144.23 person-years (2.29%) . Multiple linear regression analysis showed that the main factors affecting DALY were disability grade, diagnostic age, pneumoconiosis grade and length of dust exposure (P<0.05) . The total economic loss caused by 974 welder's pneumoconiosis patients was 1831838160.18 yuan, and the per capita loss was 1880737.33 yuan. Among them, the direct economic loss was 970917563.75 yuan (53.00%) , and the indirect economic loss was 860920596.43 yuan (47.00%) . Conclusion: Welder's pneumoconiosis causes serious disease burden to patients, and at the same time causes huge economic losses to individuals and society, which seriously hinders the development of society. Taking effective control measures to prevent the incidence of welder's pneumoconiosis is the key to reduce the disease burden.

Explosive weld joint characteristics of Copper-Tantalum via simulation.

This report aims to examine the effects of impact velocity, impact depth, and impact orientation on the Cu-Ta weld joint of the explosive welding process via MD simulation. The findings indicate that the residual shear stress in the welded block mostly increases as the impact velocity rises. The bottom Ta block is more severely distorted than the higher Cu block due to the impact direction. During the tensile test, three stress zones can be identified including the low-stress Cu block, the high-stress Ta block, and the medium-stress weld joint in the middle of the samples. The weld joint position is lower than the median line of the welded block. The Cu-Ta welded block with 500 m/s impact velocities had the highest ultimate tensile strength (UTS) value of 6.49 GPa. With increasing impact depth, the atomic strain level, residual shear stress, and weld joint dimensions all noticeably increase. The Cu-Ta welded block with an impact depth of 7.5 Å has the greatest UTS values, measuring 11.65 GPa, because of its well-crystal structure. Changing the impact orientation does not result in a dramatic change in atomic strain. Orientation (001) vs (001) has the highest strain and stress rates. With an impact orientation of (110) vs. (111), the Cu-Ta welded block gets the highest UTS value of 8.03 GPa compared to other orientations.

Experimental factors influencing the bioaccessibility and the oxidative potential of transition metals from welding fumes.

Inhalation of welding fumes (WFs) containing high levels of transition metals (Cr, Cu, Fe, Mn, Ni…) is associated with numerous health effects including oxidative stress. However, the measurements of the oxidative potential (OP) and bioaccessibility of WF transition metals depend on several physicochemical parameters and may be subject to several experimental artifacts. In this work, we investigated the influence of the experimental conditions that may affect the bioaccessibility of transition metals and their OP on stainless-steel WF extracts. WFs were produced using a generation bench and sampled on filters. The soluble fraction of the metals was analysed. Two different extraction fluids mimicking physiological pulmonary conditions were studied: phosphate buffer and Hatch's solution. Three extraction times were tested to determine the optimal time for a significant OPDTT using the dithiothreitol (DTT) method. The storage conditions of WFs after filter sampling such as duration, temperature and atmospheric conditions were investigated. The results indicate that experimental conditions can significantly affect the OPDTT and metal bioaccessibility analyses. Cr, Cu and Ni show higher solubility in Hatch's solution than in the phosphate buffer. Mn is highly sensitive to DTT and shows close solubility in the two fluids. An extraction time of 0.5 h in phosphate buffer allows a better sensitivity to OPDTT, probably by limiting complexations, interactions between metals and precipitation. Storage time and temperature can influence the physical or chemical evolution of the WFs, which can affect their OPDTT and Mn solubility. However, storage under N2(g) limits these changes. On-line measurements of OPDTT could provide an alternative to filter sampling to overcome these artifacts.

Welding fume exposure and prevalence of chronic respiratory symptoms among welders in micro- and small-scale enterprise in Akaki Kality sub-city, Addis Ababa, Ethiopia: a comparative cross-sectional study.

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.

Laser tissue welding by using collagen excitation at a 1,720 nm near-infrared optical window III.

Laser tissue welding (LTW) is a method of fusing incised tissues together. LTW has the potential to revolutionize plastic surgery and wound healing techniques by its ability to produce watertight, scarless seals with minimal foreign body reaction. While using thermal mechanisms to achieve LTW, energy from the incident laser is absorbed by water in the tissue. As the water temperature increases, partial denaturing of the collagen triple helix briefly occurs, which is quickly followed by renaturation of collagen as the tissue cools, thus providing a watertight seal. This research study investigates the efficacy of direct collagen excitation at 1,720 nm to accomplish LTW. This wavelength falls within the near-infrared (NIR) optical window III. The tensile strengths of pig skin that have been welded with NIR continuous-wave (CW) diode lasers at 1,455 nm, which promote thermal mechanisms of tissue welding, and 1,720 nm wavelengths, are compared. Near-infrared lasers tuned to 1,455 and 1,720 nm were used to weld incised pieces of porcine skin together without extrinsic solders or dyes. The tensile force of the welded tissues was measured using a digital force gauge. The average tensile force of the welded pig skin using the 1,720 nm laser was approximately four times greater than that using the CW 1,455 nm laser, suggesting that LTW accomplished through direct collagen excitation in the NIR optical window III provides greater tensile strengths.

Effects of occupational exposure to metal fume PM2.5 on lung function and biomarkers among shipyard workers: a 3-year prospective cohort study.

OBJECTIVE: This study investigates the associations of α1-antitrypsin, inter-α-trypsin inhibitor heavy chain (ITIH4), and 8-isoprostane with lung function in shipyard workers exposed to occupational metal fume fine particulate matter (PM2.5), which is known to be associated with adverse respiratory outcomes. METHODS: A 3-year follow-up study was conducted on 180 shipyard workers with 262 measurements. Personal exposure to welding fume PM2.5 was collected for an 8-h working day. Pre-exposure, post-exposure, and delta (∆) levels of α1-antitrypsin, ITIH4, and 8-isoprostane were determined in urine using enzyme-linked immunosorbent assays. Post-exposure urinary metals were sampled at the beginning of the next working day and analyzed by inductively coupled plasma-mass spectrometry. Lung function measurements were also conducted the next working day for post-exposure. RESULTS: An IQR increase in PM2.5 was associated with decreases of 2.157% in FEV1, 2.806% in PEF, 4.328% in FEF25%, 5.047% in FEF50%, and 7.205% in FEF75%. An IQR increase in PM2.5 led to increases of 42.155 µg/g in ∆α1-antitrypsin and 16.273 µg/g in ∆ITIH4. Notably, IQR increases in various urinary metals were associated with increases in specific biomarkers, such as post-urinary α1-antitrypsin and ITIH4. Moreover, increases in ∆ α1-antitrypsin and ∆ITIH4 were associated with decreases in FEV1/FVC by 0.008% and 0.020%, respectively, and an increase in ∆8-isoprostane resulted in a 1.538% decline in FVC. CONCLUSION: Our study suggests that urinary α1-antitrypsin and ITIH4 could indicate early lung function decline in shipyard workers exposed to metal fume PM2.5, underscoring the need for better safety and health monitoring to reduce respiratory risks.

[Bibliometric and visual analysis of neurological damage caused by electrical welding operations].

Objective: To analyze and summarize the trends and hot spots in the field of neurological damage caused by electric welding operations, and to provide ideas for new researches by searching the domestic and international literature. Methods: In December 2022, using Web of Science Citation Index (Web of Science), China Journal Full-Text Database (CNKI) and Wanfang Database as search databases, literature search was conducted on the Chinese and English search terms related to eletrical welding operations and neurological damage. The bibliometric analysis software VOSviewer 1.6.18 and CiteSpace 6.1.6 were used to visualize the publication year, publication quantity, country, research institution and key words of the literature. Results: A total of 309 articles (112 in Chinese and 197 in English) were included in this study. The first domestic and international papers were published in 1976 and 1994 respectively, and the number of papers reached the peak in 2006 and 2018, and then showed a downward trend to varying degrees. In China, Shandong First Medical University (including Shandong Institute of Occupational Health and Occupational Disease Prevention and Shandong Academy of Medical Sciences) and Wuhan University of Science and Technology had the largest number of publications. The 309 articles were from 52 Chinese journals and 86 English journals. The co-occurrence analysis of key words showed that the domestic research mainly focused on eletrical welding operation, welding workers, neurobehavioral function and manganese, and the nervous system damage caused by manganese in welding smoke was the field of international attention. Long term exposure, risk, and performance were key buzzwords in the field. Conclusion: The research focus in the field of nervous system damage caused by electric welding operation has an obvious trend of time evolution, gradually transiting from clinical manifestations to its toxic mechanism and early biomarkers.

TERT-independent telomere elongation and shelterin dysregulation after pulmonary exposure to stainless-steel welding fume in-vivo.

Telomeres are inert DNA sequences (TTAGGG) at the end of chromosomes that protect genetic information and maintain DNA integrity. Emerging evidence has demonstrated that telomere alteration can be closely related to occupational exposure and the development of various disease conditions, including cancer. However, the functions and underlying molecular mechanisms of telomere alteration and shelterin dysregulation after welding fume exposures have not been broadly defined. In this study, we analyzed telomere length and shelterin complex proteins in peripheral blood mononuclear cells (PBMCs) and in lung tissue recovered from male Sprague-Dawley rats following exposure by intratracheal instillation (ITI) to 2 mg/rat of manual metal arc-stainless steel (MMA-SS) welding fume particulate or saline (vehicle control). PBMCs and lung tissue were harvested at 30 d after instillation. Our study identified telomere elongation and shelterin dysregulation in PBMCs and lung tissue after welding fume exposure. Mechanistically, telomere elongation was independent of telomerase reverse transcriptase (TERT) activation. Collectively, our findings demonstrated that welding fume-induced telomere elongation was (a) TERT-independent and (b) associated with shelterin complex dysregulation. It is possible that an alteration of telomere length and its regulatory proteins may be utilized as predictive biomarkers for various disease conditions after welding fume exposure. This needs further investigation.

Risk of bladder, kidney and prostate cancer from occupational exposure to welding fumes: a systematic review and meta-analysis.

BACKGROUND: Our aimed to conduct a meta-analysis of cohort studies on risk of genitourinary (GU) cancers in workers exposed to welding fumes (WF). METHODS: We performed a systematic review of studies published on Pubmed, Scopus and Embase following PRISMA criteria. Two researchers selected cohort studies on WF exposure. From 2582 articles, 7 non-overlapping studies were included. Quality of studies was scored according to CASP. We run a random effects meta-analysis to calculate the relative risk (RR) and 95% confidence intervals (CI) of GU cancer, overall and stratified by cancer, country, and quality score. RESULTS: We included seven studies reporting results on GU cancers, including prostate, bladder and kidney cancer (PC, BC, and KC). The RR was 1.19 (95% CI = 1.07-1.32, 16 risk estimates) for GU cancer; 1.13 (95% CI = 0.90-1.42, 4 risk estimates) for PC; 1.26 (95% CI = 0.98-1.60, 7 risk estimates) for BC and 1.28 (95% CI = 1.12-1.47, 5 risk estimates) for KC. Heterogeneity was present in all meta-analyses (p < 0.001). The increased risk was more pronounced in North American than in European studies (respectively, OR = 1.35, 95% CI = 1.18-1.55; OR = 1.13, 95% CI = 1.01-1.27 p heterogeneity = 0.03). There was no heterogeneity according to quality score (p = 0.4). Data were insufficient to investigate associations by industry or welding type. Publication bias for each cancer was excluded. CONCLUSION: This meta-analysis suggests increased risk of KC and BC, but not of PC, in workers exposed to WF. Confounding by other occupational and non-occupational risk factors could not be excluded. Data were not adequate to address the risk of specific exposure circumstances.

Reported harassment and mental ill-health in a Canadian prospective cohort of women and men in welding and electrical trades.

OBJECTIVES: Experience of psychosocial environments by workers entering trade apprenticeships may differ by gender. We aimed to document perceived harassment and to investigate whether this related to mental ill-health. METHODS: Cohorts of workers in welding and electrical trades were established, women recruited across Canada and men from Alberta. Participants were recontacted every 6 months for up to 3 years (men) or 5 years (women). At each contact, they were asked about symptoms of anxiety and depression made worse by work. After their last regular contact, participants received a "wrap-up" questionnaire that included questions on workplace harassment. In Alberta, respondents who consented were linked to the administrative health database that recorded diagnostic codes for each physician contact. RESULTS: One thousand eight hundred and eighty five workers were recruited, 1,001 in welding trades (447 women), and 884 in electrical trades (438 women). One thousand four hundred and nineteen (75.3%) completed a "wrap up" questionnaire, with 1,413 answering questions on harassment. Sixty percent of women and 32% of men reported that they had been harassed. Those who reported harassment had more frequently recorded episodes of anxiety and depression made worse by work in prospective data. In Alberta, 1,242 were successfully matched to administrative health records. Those who reported harassment were more likely to have a physician record of depression since starting their trade. CONCLUSIONS: Tradeswomen were much more likely than tradesmen to recall incidents of harassment. The results from record linkage, and from prospectively collected reports of anxiety and depression made worse by work, support a conclusion that harassment resulted in poorer mental health.

Mechanical and fatigue resistance of restorations supported by welded-framework and realized using computer-aided designed prosthetic shells: In vitro pilot study.

Resin coating in implants rehabilitation cannot always be aesthetic, durable and comfortable for the patient mainly due to the limited dimensions of the final structure. Intraoral welding technique and computer-aided designed prosthetic shells may be a solution. This in vitro study evaluates the capacity of load and the weakest point of implant-supported provisional prosthesis using welded titanium framework. Twelve samples were produced to simulate an implant supported fixed prosthetic bridge. Two implants (Ankylos; Dentsply Sirona Implants; Germany) were inserted inside blocks of nanoceramic material produced with a stereolithographic 3D printer. A polymethylmethacrylate (PMMA) resin shell was performed with CAD/CAM and relined on welded framework. Six samples were produced with the same procedure reducing resin thickness. The samples were subjected to fatigue test (6,500,000 cycles) using ElectroForce 3310 fatigue machine (t1); subsequently a mechanical compression test using a universal Shimadzu AGS-X 10 machine (t2). The samples were analyzed with a photographic and radiographic documentation at t0, t1 and t2. The samples survived mechanical fatigue test without evidence of failure. The radiographic and photographic evaluation revealed the fracture of resin coating after the mechanical compression test. The samples with minimal resin thickness fractured first. Adequate assessment of the resin thickness is mandatory to improve the longevity of these rehabilitations. CAD-CAM digital prosthetic design allows us to optimize the thicknesses and the prosthetic shapes, allowing us to obtain good degrees of resistance even in the presence of reduced prosthetic spaces.

Application of Multiple Occupational Health Risk Assessment Models for Metal Fumes in Welding Process.

Welding fumes have an important role to create the adverse health effects. So, the aim of this study was to use of multiple occupational health risk assessment models for metal fumes in welding process. This cross-sectional study was conducted among welding workers. Sampling of heavy metals such as Sn, Zn, Al, Fe, Cd, Pb, Cu, Mn, Ni, Cr, and As was provided based on the National Institute for Occupational Safety and Health (NIOSH) method 7300 and analyzed by inductively coupled plasma mass spectroscopy (ICP-MS). Risk assessment was managed by four methods including Malaysia's method, Control of Substances Hazardous to Health Essentials (COSHH model), Chinese OHRA standard (GBZ/T 298-2017), and EPA method. Also, Monte Carlo simulation was used to examine the uncertainties by using the Crystal Ball tool. To compare the models, the risk levels of each model were converted into the risk ratio and the SPSS 22.0 software was used to the statistical analysis. The consistency of the two occupational health risk assessment models was examined by Cohen's Kappa. Risk ration was the highest level for Cr (VI) fumes in all models. Also, carcinogenic risk was unacceptable for all examined fumes. Moreover, non-carcinogenic risk was the highest (HI > 1) for As fumes. Mont Carlo simulations suggested that exposure time (ET) had a significant effect on the risk. Also, there was a good consistency between Malaysia method/GBZ/T 298-2017 and COSHH model/GBZ/T 298-2017. Therefore, it is recommended that the engineering and administrative controls should be provided to reduce exposure.

Experimental study on the mechanical properties and thermal damage of laser welding the ruptured flexor digitorum longus tendons.

To investigate the influence of laser parameters on the performance of tendon tissue, experiments were conducted and the process of laser-assisted tendon welding was studied. Several conclusions were drawn by analyzing the effects of laser parameters on the tensile strength, microstructure, and collagen content of tendon tissue incisions. The optimal parameters for laser welding tendon tissue were found to be a laser power of 5 W, a scanning speed of 150 mm/s, and a defocus amount of 0 mm, resulting in a laser energy density of 32.164 J/cm2 . At these parameters, the percentage of inactivated cells due to thermal damage was only 23.78%, and the tensile strength of the tendon tissue incisions reached 0.61 MPa. Additionally, the collagen content around the incision was measured to be 33.679%, composed of type I and type III collagens, with the latter accounting for 50.714% of the total collagen content.

Hazards associated with blue light emitted during gas metal arc welding of mild steel using various shielding gases and currents.

Blue light emitted during arc welding is known to potentially cause photoretinopathy. To help prevent retinal injury, it is important to identify the hazards associated with various welding conditions. The present work conducted experiments involving gas metal arc welding of mild steel under various conditions, and measured the spectral radiance of the arcs. The effective radiance values, as used by the American Conference of Governmental Industrial Hygienists (ACGIH) to quantify exposure level of blue light, were subsequently calculated from the data. The resulting values were in the range of 5.0-118 W/cm2/sr, corresponding to hazardous levels according to ACGIH guidelines. The effective radiance was increased at higher welding currents and when pulsed currents were used rather than steady currents. The blue light hazard was also affected by the type of shielding gas employed. These data confirm that it is very hazardous to stare at arcs during gas metal arc welding of mild steel. As such, appropriate eye protection is necessary during arc welding, and directly staring at the arc should be avoided.

Levels and control of welding fume exposure to total particulate, hexavalent chromium, and manganese in contracted activities in an oil refinery setting (2008-2018).

In response to increasing focus on occupational exposures to welding fume, a 10-year series of personal exposure measurements was analyzed for the two main welding processes (Shielded Metal Arc Welding or Stick and Tungsten Inert Gas welding or TIG) used in an oil refinery setting. Exposures from ancillary gouging and grinding were also analyzed. The operations were conducted under a permit-to-work system, which stipulated control measures in the form of ventilation and respiratory protective equipment (RPE) depending on the work environment, base metal, and welding process. The analysis focused on three health hazards of interest: total particulate (TP); hexavalent chromium (Cr (VI)); and manganese (Mn). The study's aims were the analysis of exposure levels related to operational conditions to verify the adequacy of required control measures and the generation of quantitative information for the development of predictive exposure models. Arithmetic mean exposures were 2.01 mg/m3 for TP (n = 94), 13.86 µg/m3 for Cr (VI) (n = 160), and 0.024 mg/m3 for Mn (n = 95). Requirements and practices for ventilation and use of RPE appeared adequate for maintaining exposure levels below maximum use concentrations. Predictive models for mean exposure levels were developed using multiple linear regression. Different patterns emerged for TP, Cr (VI), and Mn exposure determinants. Enclosed or confined work environments were associated with elevated exposure levels, regardless of the provision of local exhaust or general dilution ventilation. Carbon arc, used with gouging and grinding, contributed significantly to TP exposure (p = 0.006). The relative TP source strengths of the two main welding processes were comparable to the literature data. For Cr (VI), stick welding was associated with approximately 50-fold (p < 0.001) higher exposure potential than TIG welding. For Mn, this difference was approximately 2.5-fold. Differences were observed across the three analytes in exposure reduction efficiency of local exhaust ventilation (LEV) compared to natural ventilation, possibly due to ineffective use in confined spaces. These findings contribute to the overall understanding of TP, Cr (VI), and Mn exposures from welding and required controls in an oil refinery setting.

Impact of welding occupation on serum aluminium level and its association with physical health, cognitive function, and quality of life: a cross-sectional study.

OBJECTIVE: There is an occupational health concern about welders' inhalation of toxic aluminium fumes. We investigated whether serum aluminium level (SAL) and demographic variables can significantly predict physical health parameters, cognition, and quality of life (QoL) among welders. METHODS: The cross-sectional study involved 100 age- and location-matched men (50 welders and 50 non-welders). SAL obtained using a graphite furnace atomic absorption spectrometer, and data collected using blood pressure and body mass index (BMI) apparatuses, biodata form, pain rating scale, General Practitioner Assessment of Cognition, WHOQoL-BREF, and Nordic musculoskeletal symptoms (MSS) questionnaire were analysed using independent samples t test, chi-square, Pearson's correlation, and hierarchical linear regression. RESULTS: Welders had significantly higher SAL (mean difference [MD] = 1.77 µg/L, p < 0.001), lower QoL (MD = 3.92, p = 0.039), and higher prevalence of MSS on the neck (χ2 = 10.187, p = 0.001), shoulder (χ2 = 9.007, p = 0.003), upper back (χ2 = 6.832, p = 0.009), and knee (χ2 = 12.190, p < 0.001) than non-welders. There was a significant bivariate association between SAL, systolic blood pressure (ß = 0.313, p = 0.002), and BMI (ß = 0.279, p = 0.005), but not pain intensity, cognition, or QoL. SAL remained a significant predictor of systolic blood pressure after adjustment for physical health and QoL parameters (ß = 0.191, p = 0.044). The association between SAL and social QoL became significant after adjustment for physical health and other QoL domains (ß = - 0.210, p = 0.032) and demographic variables (ß = - 0.233, p = 0.046). CONCLUSION: Welders had significantly higher SAL, musculoskeletal symptoms, blood pressure, and lower QoL than non-welders. SAL was associated with adverse physical health parameters and social-related QoL, not cognition. We recommend routine aluminium bioavailability and physical health checks among welders.