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.

Occupational exposure to nickel and hexavalent chromium and the risk of lung cancer in a pooled analysis of case-control studies (SYNERGY).

There is limited evidence regarding the exposure-effect relationship between lung-cancer risk and hexavalent chromium (Cr(VI)) or nickel. We estimated lung-cancer risks in relation to quantitative indices of occupational exposure to Cr(VI) and nickel and their interaction with smoking habits. We pooled 14 case-control studies from Europe and Canada, including 16 901 lung-cancer cases and 20 965 control subjects. A measurement-based job-exposure-matrix estimated job-year-region specific exposure levels to Cr(VI) and nickel, which were linked to the subjects' occupational histories. Odds ratios (OR) and associated 95% confidence intervals (CI) were calculated by unconditional logistic regression, adjusting for study, age group, smoking habits and exposure to other occupational lung carcinogens. Due to their high correlation, we refrained from mutually adjusting for Cr(VI) and nickel independently. In men, ORs for the highest quartile of cumulative exposure to CR(VI) were 1.32 (95% CI 1.19-1.47) and 1.29 (95% CI 1.15-1.45) in relation to nickel. Analogous results among women were: 1.04 (95% CI 0.48-2.24) and 1.29 (95% CI 0.60-2.86), respectively. In men, excess lung-cancer risks due to occupational Cr(VI) and nickel exposure were also observed in each stratum of never, former and current smokers. Joint effects of Cr(VI) and nickel with smoking were in general greater than additive, but not different from multiplicative. In summary, relatively low cumulative levels of occupational exposure to Cr(VI) and nickel were associated with increased ORs for lung cancer, particularly in men. However, we cannot rule out a combined classical measurement and Berkson-type of error structure, which may cause differential bias of risk estimates.

The Prevalence of Musculoskeletal Symptoms among Welders and Non-Welders in Ikenne, Ogun State, Nigeria: A Comparative Cross-Sectional Study.

BACKGROUND: Musculoskeletal symptoms in welders may affect their health and quality of life. This study determined the prevalence of musculoskeletal symptoms among welders compared to non-welders and determined the body part(s) mostly affected. METHODOLOGY: The study is a comparative cross-sectional study. 142 welders and 136 security officers in Ikenne local government area of Ogun State, Nigeria were included in the study. The Nordic Musculoskeletal Questionnaire (NMQ) was used to obtain information on the prevalence of musculoskeletal disorders (MSDs). Descriptive statistics methods were used to summarize the data. Chi-square bivariate analysis was conducted to test for associations between welders' occupational characteristics and the 12-month prevalence of back pain. RESULTS: The mean age of respondents was 36.8±13.9 years and 36.7±9.4 for non-welders. Two-fifth (40.8%) of the welders had less than 10 years of work experience. About half (50.7%) of them worked six days a week, and many (54.9%) worked more than eight hours daily. The prevalence of back pain was higher among welders (74.6%) than in security officers (33.8%). This finding was significant (P<0.001). Also, knee pain was more common among welders (31.7%) compared to security officers (16.2%). The 12-month prevalence of back pain among welders and control was 74.6% and 33.8% respectively and knee pain among welders and control was 31.7% and 16.2% respectively. Both were statistically significant (p=0.001). In the last seven days, back pain was present more among welders than in controls (50.0% Vs 26.5%). CONCLUSION: The study shows a high prevalence of musculoskeletal symptoms among welders compared to non-welders. The lower back is the part of the body most affected. Training and health education of the workers on the negative effect of musculoskeletal symptoms on the body, and the right posture to adopt at work would go a long way in reducing the occurrence of these symptoms.

CONTEXTE: Les symptômes musculo-squelettiques chez les soudeurs peuvent affecter leur santé et leur qualité de vie. Cette étude a déterminé la prévalence des symptômes musculo-squelettiques chez les soudeurs par rapport aux non-soudeurs et a déterminé la ou les parties du corps les plus touchées. MÉTHODOLOGIES: L'étude est une étude transversale comparative. 142 soudeurs et 136 agents de sécurité dans la zone de gouvernement local d'Ikenne de l'État d'Ogun, au Nigéria, ont été inclus dans l'étude. Le questionnaire nordique sur les troubles musculo-squelettiques (NMQ) a été utilisé pour obtenir de l'information sur la prévalence des troubles musculo-squelettiques (TMS). Des méthodes statistiques descriptives ont été utilisées pour résumer les données. Une analyse bivariée du chi carré a été effectuée pour vérifier les associations entre les caractéristiques professionnelles des soudeurs et la prévalence des maux de dos sur 12 mois. RÉSULTATS: L'âge moyen des répondants était de 36,8±13,9 ans et de 36,7±9,4 ans pour les non-soudeurs. Les deux cinquièmes (40,8 %) des soudeurs avaient moins de 10 ans d'expérience de travail. Environ la moitié (50,7 %) d'entre eux travaillaient six jours par semaine, et beaucoup (54,9 %) travaillaient plus de huit heures par jour. La prévalence des maux de dos était plus élevée chez les soudeurs (74,6 %) que chez les agents de sécurité (33,8 %). Ce résultat était significatif (P<0,001). De plus, la douleur au genou était plus fréquente chez les soudeurs (31,7 %) que chez les agents de sécurité (16,2 %).La prévalence à 12 mois des maux de dos chez les soudeurs et les témoins était de 74,6 % et 33,8 % respectivement, et la douleur au genou chez les soudeurs et le groupe témoin était de 31,7 % et 16,2 % respectivement. Les deux étaient statistiquement significatifs (p = 0,001). Au cours des sept derniers jours, les maux de dos étaient plus présents chez les soudeurs que chez les témoins (50,0 % contre 26,5 %). CONCLUSION: L'étude montre une prévalence élevée de symptômes musculo-squelettiques chez les soudeurs par rapport aux non-soudeurs. Le bas du dos est la partie du corps la plus touchée. La formation et l'éducation sanitaire des travailleurs sur l'effet négatif des symptômes musculo-squelettiques sur le corps, et la bonne posture à adopter au travail contribueraient grandement à réduire l'apparition de ces symptômes. Mots clés: Symptômes musculo-squelettiques, Soudeurs, Nigeria, Questionnaire nordique sur les troubles musculo-squelettiques.

Ergonomic demands and fetal loss in women in welding and electrical trades: A Canadian cohort study.

OBJECTIVES: To determine the relationship between ergonomic demands of the job at conception and fetal loss (miscarriage or stillbirth). METHODS: Women with a welding or electrical trade apprenticeship were identified across Canada for the Women's Health in Apprenticeship Trades-Metal and Electrical study. They completed a reproductive and employment history at recruitment and every 6 months for up to 5 years to provide details on pregnancies and work demands. Job at conception was identified and fetal loss examined in relation to ergonomic exposures/demands, allowing for potential confounders. RESULTS: A total of 885 women were recruited; 447 in welding and 438 in electrical trades. Of these, 574 reported at least one pregnancy. Analysis of 756 pregnancies since the woman started in her trade suggested no increased risk of fetal loss in those choosing welding rather than electrical work. Among 506 pregnancies conceived during a period working in a trade, 148 (29.2%) ended in fetal loss: 31.2% (73/234) in welding, and 27.6% (75/272) in electrical work. Detailed exposure information was available for 59% (299/506) of these pregnancies. In welders, the risk of fetal loss was increased with whole-body vibration (prevalence ratio [PR] = 2.14; 95% confidence interval [CI] 1.39-3.31) and hand-arm vibration for > 1 hour/day (PR = 2.15; 95% CI 1.33-3.49). In electrical workers risk increased with more than 8 days working without a rest day (PR = 2.29; 95% CI 1.25-4.17). Local exhaust ventilation reduced risk in welders. CONCLUSIONS: There was no significant increase in fetal loss in welding trades compared to electrical work. Vibration, largely from grinding, and extended work rotations appear to be potentially modifiable factors of some importance.

Musculoskeletal disorders and level of physical activity in welders.

BACKGROUND: Welders demonstrate a high prevalence of musculoskeletal disorders (MSDs), as indicated by high rates of illness-related absenteeism. Leisure time physical activity (LTPA) could be a preventive strategy. However, little is known about LTPA prevalence and its association with MSDs among welders. AIMS: The aim of this study was to analyse the prevalence of MSD and LTPA levels among welders and to identify risk factors for the main disorder of low back pain (LBP). METHODS: The following data were collected from 145 welders from 34 companies in the German steel industry: individual factors (demographics, health behaviour), job-related factors (welding process, welding hours per day, employment years, shift work, ergonomic tools) and MSD (Nordic questionnaire). LTPA (International Physical Activity Questionnaire) was calculated to determine the metabolic equivalent of task (MET) per week as an objective measure of energy expenditure. Prevalence and multivariate regression analysis were calculated to determine odds ratios (ORs). RESULTS: The 12-month prevalence of LBP was 71%, for neck pain 61% and for shoulder pain 55%. Forty-two per cent of the participants accumulated <600 MET/week. The multivariate regression model revealed LTPA <600 MET/week (OR 3.4, 95% CI 1.05-10.85) and neck pain in the previous 12 months (OR 5.2, 95% CI 2.02-13.56) to be significantly associated with LBP. CONCLUSIONS: The results show a high prevalence of MSDs and thus a strong requirement for intervention. Therefore, LTPA should be prioritized and employers should encourage access to regular activity.

Oxidative stress status of Turkish welders.

Welding, a fabrication process that joins metals or thermoplastics by causing coalescence, is indispensable in modern society and ubiquitous in industry. Welding generates fumes that contain several metals and gases that comprise fine and ultrafine particles with the potential for adverse effects. Although health risks of welders have been evaluated in different populations, occupational exposure to welding fumes is still considered to be an important health problem, especially in developing countries. The aim of this study was to investigate the effects of welding fume exposure on important oxidative stress parameters such as superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), total glutathione (GSH), glutathione peroxidase (GPx), malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in Turkish welders (n = 48). The influence of confounding factors such as age, smoking habits, alcohol consumption, and duration of exposure on the studied parameters was also analyzed. In our study, significant decreases in the levels of GSH and activities of CAT, SOD, and GPx and significant increases of MDA, 8-OHdG levels and GR activity were found in the workers compared to the controls. There was a negative correlation between GSH levels and alcohol usage. Also, older workers (≥35 years) had significantly higher GR levels than younger workers. But smoking and alcohol usage, duration of exposure, and utilization of protective measures had no significant effect on the studied parameters in the workers. These results indicate that occupational exposure to welding fumes appears to induce oxidative stress and oxidative DNA damage.

Effects of mild steel welding fume particles on pulmonary epithelial inflammation and endothelial activation.

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.

[Research progress on the effects of welding fumes exposure on lung].

Welding is an important industrial activity worldwide which involving millions of practitioners. Due to the influence of welding method, welding dust concentration, ventilation, weather and other factors, the exposure of the welder is different. And resulting in different respiratory symptoms, including decreased lung function, welder's pneumoconiosis and even lung cancer, which seriously affects the life quality of the worker. Through referring to literatures, the research status of welding dust and respiratory diseases was summarized to provide direction for future research.

Exposure to Welding Fumes, Hexavalent Chromium, or Nickel and Risk of Lung Cancer.

To investigate the risk of lung cancer after exposure to welding fumes, hexavalent chromium (Cr(VI)), and nickel, we analyzed 3,418 lung cancer cases and 3,488 controls among men from 2 German case-control studies (1988-1996). We developed a welding-process exposure matrix from measurements of these agents, and this was linked with welding histories from a job-specific questionnaire to calculate cumulative exposure variables. Logistic regression models were fitted to estimate odds ratios with confidence intervals conditional on study, and they adjusted for age, smoking, and working in other at-risk occupations. Additionally, we mutually adjusted for the other exposure variables under study. Overall, 800 cases and 645 controls ever worked as regular or occasional welders. Odds ratios for lung cancer with high exposure were 1.55 (95% confidence interval (CI): 1.17, 2.05; median, 1.8 mg/m3 × years) for welding fumes, 1.85 (95% CI: 1.35, 2.54; median, 1.4 µg/m3 × years) for Cr(VI), and 1.60 (95% CI: 1.21, 2.12; median, 9 µg/m3 × years) for nickel. Risk estimates increased with increasing cumulative exposure to welding fumes and with increasing exposure duration for Cr(VI) and nickel. Our results showed that welding fumes, Cr(VI), and nickel might contribute independently to the excess lung cancer risk associated with welding. However, quantitative exposure assessment remains challenging.

Prevalence, pattern and factors associated with ocular disorders in small-scale welders in Katwe, Kampala.

BACKGROUND: Welders are at an increased risk of eye disorders as a result of their occupation, leading to enormous vocational and economic consequences. With limited published studies among welders in low resource settings, we sought to determine the prevalence, pattern and factors associated with ocular disorders among small-scale welders in Katwe, Kampala. METHODS: In a field-based cross-sectional study, we recruited 343 small-scale welders. Simple random sampling was done to select the study participants. A pretested questionnaire was used to collect information on demographics, ocular, general history, systemic and ocular examination. The proportion of small-scale welders with ocular disorders (defined as any abnormal finding on eye examination) was determined. The bivariate and multivariate analyses were carried out, using logistic regression methods at a level of significance of 0.05. RESULTS: The mean age of the participants was 36 years (SD ± 12). The overall prevalence of ocular disorders was found to be 59.9%. The common ocular disorders included conjunctiva disorders (32%) and presbyopia (27%). There was a statistically significant relationship between females (OR = 4.279, P-value = 0.007), age 35 and above (OR = 4.244, P-value< 0.001), history of foreign body removal (OR = 1.677, P-value = 0.041), and ocular disorders. CONCLUSIONS: There is a high prevalence of ocular disorders among small-scale welders. Conjunctiva disorders, presbyopia and myopia were the commonest. Being female, age 35 and above and foreign body removal, were significantly associated with ocular disorders among welders. Policies should be put in place to ensure all welders use proper personal -protective equipment (welding helmets), and also receive regular eye checkup and health education.

Neurobehavioral performance of patients diagnosed with manganism and idiopathic Parkinson disease.

PURPOSE: There is a lack of knowledge about neurobehavioral performance among patients with manganism and how their performance differs from that of idiopathic Parkinson disease patients (PD). This study was initiated with the aim to describe and compare neurobehavioral performance among patients diagnosed with manganism, PD and a group of referents. MATERIALS AND METHODS: Neurobehavioral performance was assessed in 34 patients diagnosed with manganism, 13 with PD, and 43 healthy workers (turners/fitters) who served as the reference group. Seventeen of the manganism patients had also been tested approximately 65 months previously. RESULTS: Manganism patients scored substantially more poorly than referents on tests for motor speed, manual dexterity and balance. They also performed more poorly than the PD patients on the postural sway test. In contrast, the PD patients had higher postural tremor intensity with narrower frequency dispersion than manganism patients. The pattern of neurobehavioral performance was more asymmetrical in PD compared to manganism patients, in particular when testing for tremor intestity, grooved pegboard and static steadiness, indicating lateralized impairment in the PD patients. The amount of bradykinesia was comparable between the patient groups. Neurobehavioral performance deteriorated slightly among 17 manganism patients followed for 65 months compared with the age-related decline among referents. CONCLUSIONS: Patients with manganism had severe bradykinesia and balance disturbances, but only slight postural tremor. In contrast, PD patients had significant postural tremor and bradykinesia, but only slight balance disturbances. Their neurobehavioral performance indicated lateralized impairment, more unilateral. Neurobehavioral performance deteriorated slightly in manganism patients during a 65-month follow-up.

A study of atherothrombotic biomarkers in welders.

INTRODUCTION: Studies have shown that welders have increased cardiovascular mortality. This may be due to airborne particulate matter (PM) exposure. Elevated levels of PM in polluted urban air have been associated with increased cardiovascular mortality and morbidity. This study seeks to explore potential mechanisms for the increased cardiovascular mortality in welders. METHODS: Seventy welders were compared to 74 referents. Exposure to PM was assessed by personal full-shift sampling of work room air the last 2 days before collection of blood samples. Selected biomarkers of pro-coagulant activity, endothelial/platelet activation and systemic inflammation were determined in the samples. RESULTS: The welders had been occupationally exposed to PM for 15 years on average. The geometric mean current exposure to PM was 8.1 mg/m3. They had statistically significantly higher concentrations of TNF-α, P-selectin, CD40L, prothrombin fragment 1 + 2 and D-dimer than the referents. Increasing concentrations of D-dimer and CD40L were observed by increasing current exposure to PM. DISCUSSION: The study shows that welders highly exposed to welding PM were in a pro-thrombotic state with increased thrombin generation and consequently higher D-dimer concentrations. The welders had also increased endothelial/platelet activation as compared to the referents. These alterations are compatible with increased cardiovascular mortality as previously reported among welders.

Modelling of exposure to respirable and inhalable welding fumes at German workplaces.

The International Agency for Research on Cancer classified welding fumes as carcinogenic to humans, and occupational exposure limits should be established to protect welders. The aim of this study is to estimate exposure levels to inhalable and respirable welding fumes by welding process to use them for exposure assessment in epidemiological studies and to derive occupational exposure limits. In total, 15,473 mass concentrations of inhalable and 9,161 concentrations of respirable welding fumes could be analyzed along with welding-related and sampling information, which were compiled in the German database MEGA between 1983 and 2016. In both particle-size fractions, model-based geometric means of the concentrations were estimated by welding process and material for frequently used welding processes adjusted for sampling time and median-centered for calendar years. The inhalable concentrations were approximately twice the respirable concentrations, with medians of 3 mg/m3 (inter-quartile range: 1.2-7.0 mg/m3) and 1.5 mg/m3 (inter-quartile range: < limit of detection -3.8 mg/m3), respectively. The adjusted geometric means of flux-cored arc welding, metal inert and active gas welding, shielded metal arc welding and torch cutting ranged from 0.9 to 2.2 mg/m3 for respirable welding fumes and from 2.3 to 4.7 mg/m3 for inhalable fumes. In both particle-size fractions, geometric means were between 0.1 and 0.9 mg/m3 when performing tungsten inert gas, autogeneous, resistance, laser, and plasma welding or spraying. Results derived from this large dataset are useful for a quantitative exposure assessment to estimate health risks of welders.

[An analysis of work-related musculoskeletal disorders and ergonomic loads in male welders in shipbuilding industry].

Objective: To investigate the prevalence of work-related musculoskeletal disorders (WMSDs) in male welders in different work areas of shipbuilding industry based on their operational working position and body position characteristics and to analyze the operational positions and ergonomic loads. Methods: In February 2017, 412 male welders from the hull and block work areas of a large ship factory were selected by stratified sampling. The prevalence and effects of WMSDs within a year were investigated using the Nordic Musculoskeletal Disorders Questionnaire, and a rapid exposure checklist was used to obtain the ergonomic load index by comprehensive scoring; the exposure-response relationship between the ergonomic loads and WMSDs symptoms of subjects in the hull and block work areas was evaluated. Results: Among the male welders working in the hull work area of shipbuilding industry, WMSDs occurred more commonly in the neck, lower back/waist, and legs, accounting for 53.16% (126/237) , 51.90% (123/237) , and 41.77% (99/237) , respectively; among those working in the block work area, WMSDs occurred more commonly in the lower back/waist, wrist, and legs, accounting for 52.57% (92/175) , 49.14% (86/175) , and 45.14% (79/175) , respectively. There were significant differences in the distribution of cases of pain within the last 7 days and one month, pain lasting more than one month, or absence from work due to pain within a year in the four positions between the two work areas (P<0.05). In the hull work area, high and extremely high exposure levels were mainly seen in the neck, lower back/waist, and legs, accounting for 76.79%(182/237), 69.20%(164/237), and 59.49%(141/237), respectively; in the block work area, high and extremely high exposure levels were mainly seen in the lower back/waist, wrist, and legs, accounting for 77.71%(136/175), 50.29% (88/175), and 46.29% (81/175), respectively. The detection rates of WMSDs in these four positions significantly increased as the exposure levels rose (P<0.01). Conclusion: The WMSDs of male welders working in the hull and block work areas of shipbuilding industry occurs more commonly in the lower back/waist and legs. The risk of WMSDs symptoms increases with the rise of ergonomic load.

Mitigation measures of electromagnetic field exposure in the vicinity of high frequency welders.

BACKGROUND: Presented information about the welding process and equipment, focusing on the emission of electromagnetic field (EMF) with levels significant in terms of the labor safety regulations in force in Poland - the ordinances of the Minister of Family, Labour and Social Policy that came into force on June 27, 2016 and June 29, 2016 - emerged due to harmonization with European Union directive 2013/35/EU of 26 June 2013 of the European Parliament and the Council. They presented methods of determination of the EMF distribution in the welding machine surroundings and analyzed the background knowledge from the available literature. MATERIAL AND METHODS: The subject of the analysis included popular high frequency welders widely used in the industry. Electromagnetic field measurements were performed in the welder operating place (in situ) during machine normal operations, using measurement methods accordant with labor safety regulations in force in Poland and according to the same guidelines, the EMF distributions and parameters having been described. RESULTS: They presented various scenarios of particular, real examples of excessive exposure to EMF in the dielectric welder surroundings and showed solutions, ranging from simple and costless and ending on dedicated electromagnetic shielding systems, which allowed to reduce EMF exposure in some cases of more than 80% (protection zone ranges) or eliminate dangerous zone presence. CONCLUSIONS: It has shown that in the dielectric welders surrounding, significant EMF strength levels may be the result of errors or omissions which often occur during development, installation, operation or modification of welding machines. It has allowed to present the measures that may significantly reduce the exposure to EMF of workers in the welder surroundings. The role of accredited laboratories in helping in such cases was underlined. Med Pr 2017;68(6):693-703.

Increase in oxidative stress levels following welding fume inhalation: a controlled human exposure study.

BACKGROUND: Tungsten inert gas (TIG) welding represents one of the most widely used metal joining processes in industry. It has been shown to generate a large majority of particles at the nanoscale and to have low mass emission rates when compared to other types of welding. Despite evidence that TIG fume particles may produce reactive oxygen species (ROS), limited data is available for the time course changes of particle-associated oxidative stress in exposed TIG welders. METHODS: Twenty non-smoking male welding apprentices were exposed to TIG welding fumes for 60 min under controlled, well-ventilated settings. Exhaled breathe condensate (EBC), blood and urine were collected before exposure, immediately after exposure, 1 h and 3 h post exposure. Volunteers participated in a control day to account for oxidative stress fluctuations due to circadian rhythm. Biological liquids were assessed for total reducing capacity, hydrogen peroxide (H2O2), malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations at each time point. A linear mixed model was used to assess within day and between day differences. RESULTS: Significant increases in the measured biomarkers were found at 3 h post exposure. At 3 h post exposure, we found a 24 % increase in plasma-H2O2 concentrations ([95%CI: 4 % to 46 %], p = 0.01); a 91 % increase in urinary-H2O2 ([2 % to 258 %], p = 0.04); a 14 % increase in plasma-8-OHdG ([0 % to 31 %], p = 0.049); and a 45 % increase in urinary-8-OHdG ([3 % to 105 %], p = 0.03). Doubling particle number concentration (PNC) exposure was associated with a 22 % increase of plasma-8-OHdG at 3 h post exposure (p = 0.01). CONCLUSION: A 60-min exposure to TIG welding fume in a controlled, well-ventilated setting induced acute oxidative stress at 3 h post exposure in healthy, non-smoking apprentice welders not chronically exposed to welding fumes. As mass concentration of TIG welding fume particles is very low when compared to other types of welding, it is recommended that additional exposure metrics such as PNC are considered for occupational risk assessments. Our findings highlight the importance of increasing awareness of TIG welding fume toxicity, especially given the realities of welding workplaces that may lack ventilation; and beliefs among interviewed welders that TIG represents a cleaner and safer welding process.

Assessment of DNA damage as an index of genetic toxicity in welding microenvironments among iron-based industries.

Welding is used extensively in different industries. Welders are always at a risk of exposure to a number of gases and metal-containing fumes in their respective microenvironments in which they work. Welding fumes consist of a wide range of complex metal oxide particles which can deposit in different parts of their bodies causing serious health problems. In the present study, 35 welders (age: 33.80 ± 1.04 years) from two iron-based industries have been assessed for DNA damage in peripheral blood lymphocytes using single-cell gel electrophoresis. An equal number of subjects (N = 35; age: 30.40 ± 1.51 years) matched to exposed subjects with respect to sex, age, socioeconomic status, smoking, and alcoholic habits were taken as controls. The results revealed that the damaged cell frequency (DCF) and mean comet tail length (CTL) in welders were significantly higher as compared to the controls (DCF: 69.74 ± 1.68 vs. 31.14 ± 1.67 and CTL: 29.21 ± 1.48 vs. 1.47 ± 0.08; p < 0.05). The effect of confounding factors such as age, duration of exposure, smoking, and drinking habits was also studied. Blood lead levels also showed a positive correlation with duration of exposure and CTL, and the overall results indicated an increased genetic damage as an index of genotoxicity in workers occupationally engaged in welding microenvironments.

Pulmonary fibrosis and exposure to steel welding fume.

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

Primary DNA damage in welders occupationally exposed to extremely-low-frequency magnetic fields (ELF-MF).

BACKGROUND: Electric arc welding is known to involve considerable exposure to extremely-low-frequency magnetic fields (ELF-MF; 50 Hz). The aim of the present study was to evaluate individual exposure to ELF-MF during arc welding and to assess the eventually associated genotoxic hazard by evaluating primary DNA damage. METHODS: The study group comprised 21 electric arc welders (exposed) and 21 non-exposed control subjects (healthy blood donors). Occupational exposure to ELF-MF was measured using personal dosimeters worn during one complete work-shift (7 am to 5 pm). The extent of primary DNA damage was measured in peripheral blood leukocytes with the standard procedure of the alkaline comet assay. RESULTS: Tail length showed to have similar values in welders and controls. Whereas, the data showed a significant decrease for tail intensity (p = 0.01) and tail moment (p = 0.02) counts in exposed subjects compared to controls. CONCLUSIONS: The different results of our present study and published investigations from other research groups reporting positive results in the comet assay might be a result of different chromium and/or nickel (or other metals) exposure levels, which lead to DNA-protein cross-links at lower concentrations and DNA single-strand breakages at higher concentrations. Since these results are derived from a small-scale pilot study, a larger scale study should be undertaken.

Modulatory role of welding fumes on serum zinc and copper levels and oxidative stress markers among welders: Considering smoking as a possible implication.

The presence of heavy metals in welding fumes and the numerous metals that make up welding gases expose welders to numerous occupational dangers, including major occupational health issues worldwide. The gases from welding are a significant and highly skilled process that have a considerable negative impact on welders' overall health and wellbeing. This study evaluated the influence of welding fumes on serum zinc and copper levels and oxidative stress biomarkers in welders considering smoking as a potential risk factor. The study used a case-control experimental design. Forty (40) healthy adult males were randomly selected comprising twenty (20) in the experimental group involving smokers and nonsmokers with welding experience and twenty (20) in the control group involving smokers and nonsmokers without welding experience. Data are expressed as the mean±SEM, and comparisons of means across groups were performed using one-way ANOVA, followed by Turkey's multiple comparisons test. The results showed that the serum zinc and copper levels of smokers were significantly (p < 0.05) increased in comparison to the control group, and a graded increase in the serum GST and MDA levels was observed across groups. The serum SOD level of smoker nonwelders was significantly (p < 0.05) increased when compared with the control group. Smokers who did not weld had significantly (p < 0.05) higher serum SOD levels. The results likewise showed a statistically nonsignificant reduction in glutathione levels and a substantial decrease in total antioxidant capacity (TAC) in the experimental group. Overall, changes in the antioxidant parameters showed that smoking and welding fumes can exacerbate an increase in the activity of reactive oxygen species (ROS), resulting in deteriorated health conditions.