Effect of welding fumes on the cardiovascular system: a six-year longitudinal study

Inflammatory Responses to Zn/Cu-Containing Welding Fume in Human Alveolar Epithelial and Macrophage Cell Lines, with MIP-1β/CCL4 as a Much More Sensitive Macrophage Activation Marker than IL-8 and TNF-α

Zinc (Zn)- and copper (Cu)-containing welding fumes elevate inflammatory markers (CRP, TNF-α, IL-6, IL-8) in healthy individuals and welders. Zn- and Cu-containing nanoparticles are toxic to human macrophages. Therefore, ZnO exposure limits are under discussion. In this study, the effects of Zn/Cu-containing welding fume suspensions on A549 alveolar epithelial cells (exposure concentrations: 0.01/0.1/1/10/100 µg/mL) and THP-1 macrophages (additionally 0.001 µg/mL) were investigated over a period of 48 h. Effects on apoptosis, cytotoxicity, genotoxicity, superoxide dismutase (SOD) activity, and cytokine levels (IL-6, IL-8, MIP-1β/CCL4, TNF-α) were evaluated. Welding fume exposure increased SOD activity, and it increased Annexin-V binding and cytotoxicity effects starting at 10 µg/mL in A549 cells and particularly in THP-1 macrophages. A549 cells showed increased IL-6 at 10 and 100 µg/mL, and significant IL-8 release occurred at 10 µg/mL for A549 and 0.1 µg/mL for macrophages. Exposed macrophages released TNF-α at 1 µg/mL after 24 and 48 h and MIP-1β/CCL4 at 0.01 µg/mL after 6 h and at 0.001 µg/mL after 48 h. No genotoxic effects were detected. MIP-1β/CCL4 is a sensitive new biomarker for human macrophages exposed to Zn/Cu-containing welding fumes. The findings suggest that Zn/Cu particles affect lung cells already at doses below current occupational thresholds.

Occupational epidemiological characteristics of noise-induced hearing loss and the impact of combined exposure to noise and dust on workers' hearing-a retrospective study

Introduction

The aim of the study was to investigate the occupational epidemiological characteristics of hearing loss among noise-exposed workers through a cross-sectional study and to explore the impact of combined noise and dust exposure on workers' hearing loss through a longitudinal study.

Results

This cross-sectional study revealed that the risk of speech-frequency hearing loss increases with age (OR = 1.096, 95%CI = 1.081-1.111). Independent factors influencing high-frequency hearing loss include sex, age, hazardous factors, industry category, and enterprise size. Scientific research and technical services (OR = 1.607, 95%CI = 1.111-2.324), wholesale and retail (OR = 2.144, 95%CI = 1.479-3.107), manufacturing (OR = 1.907, 95%CI = 1.429-2.545), and other industries (OR = 1.583, 95%CI = 1.002-2.502) are risk factors for high-frequency hearing loss, whereas being female (OR = 0.297, 95%CI = 0.236-0.373) is a protective factor against high-frequency hearing loss. Independent factors influencing occupational noise-induced hearing loss include sex, working age, hazardous factors, industry category, smoking, and drinking, with the risk of occupational noise-induced hearing loss increasing with working age (OR = 1.045, 95%CI = 1.031-1.058). Noise and dust work (OR = 1.271, 95%CI = 1.011-1.597), other work (OR = 0.619, 95%CI = 0.479-0.800), manufacturing (OR = 2.085, 95%CI = 1.336-3.254), other industries (OR = 2.063, 95%CI = 1.060-4.012), occasional smokers (OR = 0.863, 95%CI = 0.652-1.142), regular smokers (OR = 1.216, 95% CI = 0.987-1.497), and excessive drinkers (OR = 2.171, 95%CI = 1.476-3.193) are risk factors for occupational noise-induced hearing loss, whereas being female (OR = 0.496, 95%CI = 0.347-0.709) is a protective factor against occupational noise-induced hearing loss. The longitudinal study revealed differences in pure-tone hearing threshold test results at 500 Hz, 1,000 Hz, 3,000 Hz, 4,000 Hz, and 6,000 Hz in both ears before and after enrollment among noise-exposed workers (p < 0.05). Combined noise and dust exposure (OR = 4.660, 95%CI = 1.584-13.711), 1st year (OR = 1.540, 95%CI = 1.128-2.103), 2nd year (OR = 1.994, 95%CI = 1.409-2.821), and 3rd year (OR = 1.628, 95%CI = 1.170-2.264) were risk factors for high-frequency hearing loss.

Discussion

Combined noise and dust exposure is a risk factor for occupational noise-induced hearing loss. Additionally, occupational noise-induced hearing loss is influenced by gender, working age, enterprise industry category, smoking, and drinking. Employers should enhance occupational health management and improve workers' occupational health literacy, with a particular focus on older male workers of long working age, and those with unhealthy habits. Combined exposure to noise and dust may have a synergistic effect on causing high-frequency hearing loss, and comprehensive protective measures should be implemented for workers exposed to both.

Longitudinal changes in cardiovascular disease-related proteins in welders

OBJECTIVE

Occupational exposure to welding fumes is linked to a higher risk of cardiovascular disease; however, the threshold exposure level is unknown. Here, we aimed to identify changes in proteins associated with cardiovascular disease in relation to exposure to welding fumes.

METHODS

Data were obtained from two timepoints six years apart for 338 non-smoking men (171 welders, 167 controls); of these, 174 (78 welders, 96 controls) had measurements available at both timepoints. Exposure was measured as personal respirable dust (adjusted for personal protective equipment), welding years, and cumulative exposure. Proximity extension assays were used to measure a panel of 92 proteins involved in cardiovascular processes in serum samples. Linear mixed models were used for longitudinal analysis. The biological functions and diseases related to the identified proteins were explored using the Ingenuity Pathway Analysis software.

RESULTS

At both timepoints, the median respirable dust exposure was 0.7 mg/m3 for the welders. Seven proteins were differentially abundant between the welders and controls and increased incrementally with respirable dust: FGF23, CEACAM8, CD40L, PGF, CXCL1, CD84, and HO1. CD84 was significant after adjusting for multiple comparisons. These proteins have been linked to disorders of blood pressure, damage related to clogged blood vessels, and chronic inflammatory disorders.

CONCLUSION

Exposure to mild steel welding fumes below current occupational exposure limits for respirable particles and welding fumes in Europe and the US (1-5 mg/m3) was associated with changes in the abundance of proteins related to cardiovascular disease. Further research should evaluate the utility of these proteins as prospective biomarkers of occupational cardiovascular disease.

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.

Fifty years of research in the Scandinavian Journal of Work, Environment & Health

OBJECTIVE

The Scandinavian Journal of Work, Environment & Health was launched 50 years ago. In this paper we describe how research topics have changed over time.

METHODS

A complete list of all 2899 articles in the past 50 years was compiled. Each article was coded for type of exposure, type of health outcome, research design, first author, and country of correspondence address. Count of citations was based on the Scopus database.

RESULTS

Overall, the attention for chemical exposure in the first 30 years has shifted towards the psychosocial work environment, shift work, and physical work load. These shifts in exposure are mirrored by increased attention over time for mental disorders and musculoskeletal disorders. Cardiovascular disorders and cancer have been studied consistently over the past 50 years. Researchers from Scandinavian countries have been responsible for about 50% of the Journal's content, while authorship has broadened to about 30 countries in recent years.

CONCLUSION

During the past 50 years, some research topics have consistently remained highly visible in the Journal, whereas other topics have gained or lost interest. In terms of authors' contribution, the Journal has its roots in research from the Nordic countries, but has evolved over time as a truly international periodical with a well-recognized position in research on occupational health.

Assessment of welding fume impacts in a confined workplace by two extraction patterns - a case study of small-scale manufacturing industries

Welding fume exposure at work is recognized as a known concern for public health. This study aims to assess the welding fumes produced during welding using two different extraction patterns and to compare their influences. A thorough assessment of domestic arc welders in the erode district of India was done to assess their exposure to welding gases. The survey results chose the gas metal arc welding (GMAW) process for future investigation. The stainless-steel grade SS 316 L was used in this study. To weld 3-mm, 5-mm, and 6-mm-thick stainless-steel specimens, ER316 L filler wire and four shielding gas compositions were used. Two distinct, cost-effective welding hoods with a square duct section and a conical duct section were constructed to examine welding gases. The produced fume was collected on a 240 mm glass fibre filter and re-weighted during welding. Gas flow rates of 5, 10, and 15 LPM were investigated, with current intensities of 150A, 200A, and 275A. A novel attempt has been made to compare fume formation rates (FFR) obtained using two extraction patterns. According to this investigation, weld fume hoods with conical duct sections extract more welding gases than square duct sections. The extraction rate using two extraction patterns was compared. Furthermore, the addition of CO₂ to any shielding gas mixture results in a higher fume formation rate. The experimental FFR values were quite close to the American Welding Society (AWS) specifications. This finding also revealed that welders' socio-demographic characteristics, such as age, marital status, level of education, and work experience, influenced their awareness of occupational hazards and personal protection equipment (PPEs). As a result, there should be a strong emphasis on hazard identification education and strict enforcement of proper PPEs use among small-scale welders in and around the erode district to protect welders from a variety of hazards.

Short-term and residential exposure to air pollution: Associations with inflammatory biomarker levels in adults living in northern France

INTRODUCTION

Air pollution has an impact on health, and low-grade inflammation might be one of the underlying mechanisms. The objective of the present study of adults from northern France was to assess the associations between short-term and residential exposure to air pollution and levels of various inflammatory biomarkers.

METHODS

The cross-sectional Enquête Littoral Souffle Air Biologie Environnement (ELISABET) study was conducted from 2011 to 2013 in the Lille and Dunkirk urban areas of northern France. Here, we evaluated the associations between PM₁₀, NO₂ and O₃ exposure (on the day of the blood sample collection and on the day before, and the mean annual residential level) and levels of the inflammatory biomarkers high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-17A, IL-22, and tumor necrosis factor α.

RESULTS

We assessed 3074 participants for the association with hsCRP and a subsample of 982 non-smokers from Lille for the association with plasma cytokine levels. A 10 μg/m³ increment in PM₁₀ and NO₂ levels on the day of sample collection and on the day before was associated with a higher hsCRP concentration (3.43% [0.68; 6.25] and 1.75% [-1.96; 5.61], respectively, whereas a 10 μg/m³ increment in O₃ was associated with lower hsCRP concentration (-1.2% [-3.95; 1.64]). The associations between mean annual exposure and the hsCRP level were not significant. Likewise, the associations between exposure and plasma cytokine levels were not statistically significant.

CONCLUSION

Short-term exposure to air pollution was associated with higher serum hsCRP levels in adult residents of two urban areas in northern France. Our results suggest that along with other factors, low-grade inflammation might explain the harmful effects of air pollution on health.

Occupational exposure to particles and biomarkers of cardiovascular disease-during work and after vacation

Objective

Ambient particle matter is a risk factor for cardiovascular disease (CVD). However, little is known about associations between particles in occupational settings and risk of CVD. We investigated associations between occupational dust exposure and biomarkers of CVD, and potential recovery effects after vacation.

Methods

Personal dust exposure measurements (respirable silica, respirable dust < 4 µm, and particles of 0.1–10 µm (PM 0.1–10) were conducted once, and biological sampling were performed twice on non-smoking, male construction workers in Stockholm county, Sweden; during work and immediately after summer vacation. Linear regressions with adjustments for confounders and covariates were performed evaluating associations between occupational dust exposure and biomarkers. Paired t tests were performed evaluating changes before and after vacation.

Results

Sixty-five workers participated. Homocysteine concentrations were significantly higher with increasing concentrations (mg/m³) of respirable silica, respirable dust, and PM 0.1–10, and pulse rate with higher levels of respirable dust and dust of PM 0.1–10. Homocysteine levels were also positively correlated to number of years of dust exposure, as were low-density lipoprotein (LDL) levels. A clear recovery effect was present for LDL after vacation, but not for homocysteine.

Conclusions

Occupational dust exposure was associated with some CVD risk markers, even at mean exposure concentrations below the Swedish occupational exposure limits for respirable silica and respirable dust, respectively. Vacation resulted in recovery for some risk markers. However, the change of the homocysteine and LDL levels suggest a long-term effect. Reduction of occupational exposure to dust may decrease the risk of CVD among exposed workers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00420-022-01900-5.

Respiratory health disorders among workers in some Egyptian welding enterprises

Welding fumes contain a complex mixture of metallic oxides that pose a risk to welders' respiratory systems. This study aimed to evaluate respiratory health disorders among workers in some Egyptian welding enterprises and their relationship to the workplace environment. This research was performed from January 1^st, 2019 to February 28^th, 2021 in welding enterprises in Birket El-Sabaa, a randomly selected district of Menoufia governorate, Egypt. A cross-sectional comparative study was conducted on 110 welders and 110 non-occupationally exposed subjects. Environmental studies were carried out for total welding fumes, respirable dust, and manganese air levels. Spirometric measures and manganese levels in whole blood were applied. Analysis of the personal air samples revealed that the mean values of welding fumes, respirable dust, and manganese air levels were higher than the international permissible levels. Welders had a higher significant prevalence of respiratory manifestations (rhinitis, cough, expectoration, wheezes, dyspnea, and chronic bronchitis) as well as decreased spirometric measures (FVC%, FEV₁%, FEV₁/FVC%, and FEF_25-75%) than controls. The mean value of whole blood manganese level was statistically significantly higher among welders than that of the controls (3.35 ± 0.5 and 1.81 ± 0.79 ng/mL; respectively). A significant relationship was reported between longer work time and the prevalence of respiratory manifestations and decreased spirometric measurements. The use of masks/respirators was associated with a reduced prevalence of respiratory manifestations. Finally, welders that are exposed to welding fumes at concentrations higher than the permissible levels in welding establishments suffer from adverse respiratory problems, as shown by increased prevalence of respiratory manifestations and lower spirometric measurements. Regular use of high-quality personal protective equipment, especially masks, as well as periodic medical examinations for welders, is highly urged.

Exposure to Mild Steel Welding and Changes in Serum Proteins With Putative Neurological Function-A Longitudinal Study

Welders are exposed to high levels of metal particles, consisting mainly of iron and manganese (Mn) oxide. Metal particles, especially those containing Mn can be neurotoxic. In this exploratory study, we evaluated associations between welding and expression of 87 putative neurology-related proteins in serum in a longitudinal approach. The study cohort from southern Sweden included welders working with mild steel (n = 56) and controls (n = 67), all male and non-smoking, which were sampled at two timepoints (T1, T2) 6-year apart. Observed associations in the longitudinal analysis (linear mixed models) were further evaluated (linear regression models) in another cross-sectional sample which included welders (n = 102) and controls (n = 89) who were sampled only once (T1 or T2). The median respirable dust levels for welders after adjusting for respiratory protection was at T1 0.6 (5–95 percentile: 0.2–4.2) and at T2 0.5 (0.1–1.8) mg/m³. The adjusted median respirable Mn concentration was at T2 0.049 mg/m³ (0.003–0.314) with a Spearman correlation between adjusted respirable dust and respirable Mn of r_S = 0.88. We identified five neurology-related proteins that were differentially expressed in welders vs. controls in the longitudinal sample, of which one (nicotinamide/nicotinic acid mononucleotide adenylyltransferase 1; NMNAT1) was also differentially expressed in the cross-sectional sample. NMNAT1, an axon-protective protein linked to Alzheimers disease, was upregulated in welders compared with controls but no associations were discerned with degree of exposure (welders only: years welding, respirable dust, cumulative exposure). However, we identified five additional proteins that were associated with years welding (GCSF, EFNA4, CTSS, CLM6, VWC2; welders only) both in the longitudinal and in the cross-sectional samples. We also observed several neurology-related proteins that were associated with age and BMI. Our study indicates that low-to-moderate exposure to welding fumes is associated with changes in circulating levels of neurology-related proteins.