Ocular Protection Practice and Associated Factors Among Ethiopian Welders: Institution-Based Cross-Sectional Study

Introduction

Work-related ocular injury is a global public health problem, particularly among welders and is reduced through proper ocular protection practice. No previous studies have explored ocular protection practice and associated factors among welders in Ethiopia or in the study area.

Objective

This study aimed to assess the proportion of ocular protection practice and associated factors among welders in Gondar city, Northwest Ethiopia.

Methods

An institution-based cross-sectional study was conducted among 403 welders in Gondar city, selected using systematic random sampling with an interval of 2, from July 6 to 23, 2021. Data were collected using a pre-tested structured questionnaire and an observational checklist. Binary logistic regression was used to identify factors associated with ocular protection practice and association was expressed using an adjusted odds ratio with a 95% confidence interval (CI). Variables with a P-value of less than 0.05 were considered statistically significant.

Results

Of 396 participated welders, 81.8% worked without job training, and 33.1% had faced ocular injury. Nearly 86% of welders had access to personal protective eyewear but their knowledge and attitude towards personal protective eyewear were 48.2% (95% CI: 44.8, 51.4) and 61.4% (95% CI: 57.6, 64.7), respectively. The proportion of a good-level of ocular protection practice was 56.8% (95% CI: 52.8, 61.9). Being gas welder (adjusted odds ratio [AOR]=0.26, 95% CI: 0.12, 0.53), work experience (AOR = 1.10, 95% CI: 1.01, 1.21), job training (AOR = 4.90, 95% CI: 2.32, 10.35), welders rated the cost of personal protective eyewear as fair (AOR = 2.30, 95% CI: 1.26, 4.20) and history ocular injury (AOR = 4.20, 95% CI: 2.40, 6.97) were positively associated with a good-level proportion of ocular protection practice.

Conclusion

This study found that the proportion of a good-level of ocular protection practice of welders was fair. Being gas welder, job training, work experience, history of ocular injury and welders rated the cost of personal protective eyewear as fair were significantly associated with a good-level of ocular protection practice.

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.

Investigating the field effectiveness of respirators against metal particle exposure in various workplaces: a systematic review

Welders are exposed to high levels of metal fumes, which could be resulting in various health impairments. Respirators became a practical protective option in workplaces, as they are lightweight and easy to use. This systematic review attempts to explore the field effectiveness of using respirators to reduce metal particle exposure in workplaces. We reviewed papers published from 1900 to April 2019 in five major bibliographic databases, including Embase, Web of Science, Medline, Scopus, and CINAHL, along with organizational websites to cover gray literature. In total, 983 references were identified from the databases, out of which, 520 duplicates were removed from the EndNote database. The remaining 463 references were screened for their title and abstract. Out of 463, 70 references went through the full-text screening. Finally, eight papers, including 19 workplace respirator studies, satisfied all the inclusion criteria and were reviewed in this report. The geometric means for metal levels in workers' breathing zone with and without respirators were 9.4 and 1,777 µg/m³ for iron, 1.1 and 139 µg/m³ for lead, 2.1 and 242 µg/m³ for zinc, and 27 and 1,398 µg/m³ for manganese oxide, respectively. Most reviewed studies reported significant differences between measured metal particle levels among workers who worn respirators and who did not. In addition, results showed that N95 provided significantly less protection than elastomeric half facepieces, full-face respirators, and powered air-purifying respirators (p<0.001). More field studies are recommended to investigate Workplace Protection Factor (WPF) and fit factor (FF) of different respirators to understand the actual protection levels that they could be provided to control welding fume exposure among welders in various workplaces.

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.

Instructor Training on Opioids and the Workplace, Prevention and Response in the Plumbing and Pipe-Fitting Industry: An Interview With Cheryl Ambrose

Workers in the plumbing and pipe-fitting industry experience a wide variety of physical and emotional pain related to job hazards and lifestyle issues. Pain treatment and stress can lead to prescription or illicit substance use. The United Association of Journeymen and Apprentices of the Plumbing and Pipe-Fitting Industry of the United States and Canada has taken on these issues by adapting training developed by the National Institute of Environmental Health Sciences, Opioids and the Workplace, Prevention and Response Training. Under the leadership of Cheryl Ambrose, Health, Safety, and Environmental Administrator, the United Association of Journeymen and Apprentices of the Plumbing and Pipe-Fitting Industry of the United States and Canada has added an instructor training course and is tailoring the National Institute of Environmental Health Sciences curriculum to industry and union needs.

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.

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.

The effects of occupational exposure to manganese fume on neurobehavioral and neurocognitive functions: An analytical cross-sectional study among welders

This study aimed to measure concentrations of manganese fume in breathing zone (BZ) and blood among welders to assess neurocognitive and neurobehavioral functions among them. In this study 38 welders and 27 administrative employees participated. Q16 questionnaire was used to evaluate neurobehavioral symptoms. The computerized Stroop test and Continuous Performance Test (CPT) were used to assess neurocognitive functions. Sampling and analysis of manganese fumes in the BZ and blood samples were performed according to NIOSH-7300 and NIOSH-8005 methods, respectively. Average concentration of manganese in the welders' BZ and blood was 0.81 ± 0.21 mg/m³ and 18.33 ± 5.84 µg/l. Frequency of neurobehavioral symptoms was significantly higher in welders compared with control group. Spearman correlation test showed a moderate correlation between Mn concentrations in the BZ and blood Mn levels (r_s = 0.352). There were statistical moderate and strong correlations between the frequency of neurobehavioral symptoms and manganese concentrations in the BZ (r=0.504) and blood Mn levels (r=0.643).The Pearson correlation coefficient (r=0.433-0.690) obtained on the psychological tests showed a moderate to strong correlation between manganese concentrations in the welders' BZ and blood and some indices of the Stroop test and CPT. The results of this study can confirm the effect of manganese inhalation on creating neurobehavioral and neurocognitive impairments in welders.

Higher Hippocampal Mean Diffusivity Values in Asymptomatic Welders

Chronic high-level manganese (Mn)-induced neurotoxicity has been associated with Mn accumulation in the basal ganglia and higher risk for developing parkinsonism. Recent studies in Mn-exposed animals revealed Mn accumulation in the hippocampus, the presence of Aβ diffuse plaques, and deficits in associative learning, the latter being hallmarks of Alzheimer's disease (AD) or related disorders. This and recent evidence of hippocampal Mn accumulation in welders prompted us to test the hypothesis that welders with chronic Mn exposure would display changes in the hippocampus. Subjects with (welders; n = 42) or without (controls; n = 31) welding history were studied. Mn exposure was estimated by occupational questionnaires, whole blood Mn, and R1 imaging (estimate of short-term brain Mn accumulation). Hippocampal diffusion tensor imaging (DTI; estimate of microstructural brain changes) and volume were determined. Compared with controls, welders displayed no significant difference in hippocampal volume (p = .165). Welders, however, exhibited higher DTI hippocampal mean diffusivity (MD) values compared with controls (p = .035) that was evident particularly in older welders (>50 years, p = .002). Hippocampal MD was associated significantly with age in welders (R = 0.59; p < .001) but not in controls (p = .16). Moreover, higher hippocampal MD values (age adjusted) were associated with long-term cumulative Mn exposure (R = 0.36, p = .021). Welders with chronic exposure have higher MD values in the hippocampus that become greater with increasing age, a brain change that is similar to that observed in those at risk for AD. The current results suggest that Mn exposure, coupled with aging, may make welders more vulnerable to AD or AD-like changes.

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.

Skin cancer protective behaviors among welders of west of Iran: Importance of access to protective equipment

BACKGROUND

Welders are normally at risk of skin cancer due to continuous contact with natural ultraviolet rays and welding radiation. Protective behaviors against the radiations are the most fundamental measures taken to prevent skin cancer in these individuals.

AIMS

This research aimed to evaluate the factors affecting the protective behaviors in welders.

PATIENTS/METHODS

In this cross-sectional research, participants were selected by the census method, and the research tool was a reliable and valid questionnaire filled by 154 welders in Yasuj, Iran. Data analysis was performed in SPSS version 16 using ANOVA, Pearson's correlation coefficient, and independent t test.

RESULTS

The highest age frequency was related to the age-group of 36-45 years, and the highest frequency of work experience was less than 10 years. In terms of the level of education, most welders had a diploma or a higher degree. In addition, most behaviors reported included using gloves, whereas the least applied method was using sunscreen cream, the most important cause of which was the high cost of the cream. In this regard, the Pearson's correlation coefficient demonstrated a negative association between skin cancer and job difficulty. In addition, performing of protective behaviors decreased in the target group by aging.

CONCLUSION

Given the unfavorable mean skin cancer protective behaviors in the welders, it is recommended that interventions, such as planned education, access to protective tools, and periodic skin examinations by a physician, be carried out to promote the health of these individuals and facilitate performing protective behaviors.

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.

The potential hazardous effect of exposure to iron dust in Egyptian smoking and nonsmoking welders

Exposure to iron dust and welding fumes is widespread and may increase the risk of lung inflammation. The aim of this study was to identify associations between exposure to iron/welding fumes and the levels of inflammatory parameters and allergic mediators among 120 Egyptian men. Forty nonsmoking and 40 smoking Egyptian welders as well as 40 healthy volunteers who were never exposed to welding fumes and were nonsmoking were enrolled in the study. Peak expiratory flow rates (PEFR) assessed at the end of the shift of work on working days revealed an impairment in lung function, with the smoking workers showing the worse results, followed by nonsmoking workers, as compared to healthy volunteers. Moreover, the results of the present study showed a significant increase in serum iron and immunoglobulin E, as well as plasma thiobarbaturic acid reactive substances, C-reactive protein, tumor necrosis factor-alpha, haptoglobin, interleukin-2, interleukin-6 and interleukin-23 histamine, lactate dehydrogenase isoenzyme-3, and calcitonin. In addition, the results revealed significant decrease in plasma α-1-antitrypsin and serum transferrin, as well as blood activities of antioxidant enzymes: catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase (as compared with control group). However, there was a nonsignificant change in arginase and α-L-fucosidase in smoking and nonsmoking welders exposed to iron dust and welding fumes. In conclusion, occupational exposure to iron dust and welding fumes increases lung inflammation risk among Egyptian blacksmith workers, a condition that worsens with smoking.

Physical workload and musculoskeletal disorders in back, shoulders and neck among welders

This study aimed to determine the effect of the physical workload on the back, neck and shoulders of welders. The prevalence of musculoskeletal symptoms was assessed using the Nordic questionnaire among 15 welders. The physical workload of the neck, back and upper arms was then measured by means of inclinometry as the welders were working. The results revealed that the highest prevalence of musculoskeletal disorders during the previous 12 months was in the lower back and shoulders. The median trunk and neck flexion were significantly associated with back and neck pain in welders with symptoms during the past year (p < 0.05). Physical exposure in welders with pain was characterized by significantly more awkward postures and percentage of time spent with the trunk and neck flexed more than 20°. The nature of their work and the design of their workstations may be causes of the symptoms they experienced during work.

Editor's Highlight: Lower Fractional Anisotropy in the Globus Pallidus of Asymptomatic Welders, a Marker for Long-Term Welding Exposure

INTRODUCTION

Welding fumes contain several metals including manganese (Mn), iron (Fe), and copper (Cu) that at high exposure may co-influence welding-related neurotoxicity. The relationship between brain accumulation of these metals and neuropathology, especially in welders with subclinical exposure levels, is unclear. This study examined the microstructural integrity of basal ganglia (BG) regions in asymptomatic welders using diffusion tensor imaging (DTI).

METHODS

Subjects with (n = 43) and without (age- and gender-matched controls; n = 31) history of welding were studied. Occupational questionnaires estimated short-term (HrsW; welding hours and E90; cumulative exposure, past 90 days) and long-term (YrsW; total years welding and ELT; cumulative exposure, lifetime) exposure. Whole blood metal levels (Mn, Fe, and Cu) were obtained. Brain MRI pallidal index (PI), R1 (1/T1), and R2* (1/T2*) were measured to estimate Mn and Fe accumulation in BG [caudate, putamen, and globus pallidus (GP)]. DTI was used to assess BG microstructural differences, and related with exposure measurements.

RESULTS

When compared with controls, welders had significantly lower fractional anisotropy (FA) in the GP. In welders, GP FA values showed non-linear relationships to YrsW, blood Mn, and PI. GP FA decreased after a critical level of YrsW or Mn was reached, whereas it decreased with increasing PI values until plateauing at the highest PI values. GP FA, however, did not show any relationship with short-term exposure measurements (HrsW, E90), blood Cu and Fe, or R(2)* values.

CONCLUSION

GP FA captured microstructural changes associated with chronic low-level Mn exposure, and may serve as a biomarker for neurotoxicity in asymptomatic welders.

Increased R2* in the Caudate Nucleus of Asymptomatic Welders

Welding has been associated with neurobehavioral disorders. Welding fumes contain several metals including copper (Cu), manganese (Mn), and iron (Fe) that may interact to influence welding-related neurotoxicity. Although welding-related airborne Fe levels are about 10-fold higher than Mn, previous studies have focused on Mn and its accumulation in the basal ganglia. This study examined differences in the apparent transverse relaxation rates [R2* (1/T2*), estimate of Fe accumulation] in the basal ganglia (caudate nucleus, putamen, and globus pallidus) between welders and controls, and the dose-response relationship between estimated Fe exposure and R2* values. Occupational questionnaires estimated recent and lifetime Fe exposure, and blood Fe levels and brain magnetic resonance imaging (MRI) were obtained. Complete exposure and MRI R2* and R1 (1/T1: measure to estimate Mn accumulation) data from 42 subjects with welding exposure and 29 controls were analyzed. Welders had significantly greater exposure metrics and higher whole-blood Fe levels compared with controls. R2* in the caudate nucleus was significantly higher in welders after controlling for age, body mass index, respirator use, caudate R1, and blood metals of Cu and Mn, whereas there was no difference in R1 values in the basal ganglia between groups. The R2* in the caudate nucleus was positively correlated with whole-blood Fe concentration. This study provides the first evidence of higher R2* in the caudate nucleus of welders, which is suggestive of increased Fe accumulation in this area. Further studies are needed to replicate the findings and determine the neurobehavioral relevance.

T1 Relaxation Rate (R1) Indicates Nonlinear Mn Accumulation in Brain Tissue of Welders With Low-Level Exposure

Although the essential element manganese (Mn) is neurotoxic at high doses, the effects of lower exposure are unclear. MRI T1-weighted (TIW) imaging has been used to estimate brain Mn exposure via the pallidal index (PI), defined as the T1W intensity ratio in the globus pallidus (GP) versus frontal white matter (FWM). PI may not, however, be sensitive to Mn in GP because Mn also may accumulate in FWM. This study explored: (1) whether T1 relaxation rate (R1) could quantify brain Mn accumulation more sensitively; and (2) the dose-response relationship between estimated Mn exposure and T1 relaxation rate (R1). Thirty-five active welders and 30 controls were studied. Occupational questionnaires were used to estimate hours welding in the past 90 days (HrsW) and lifetime measures of Mn exposure. T1W imaging and T1-measurement were utilized to generate PI and R1 values in brain regions of interest (ROIs). PI did not show a significant association with any measure of Mn and/or welding-related exposure. Conversely, in several ROIs, R1 showed a nonlinear relationship to HrsW, with R1 signal increasing only after a critical exposure was reached. The GP had the greatest rate of Mn accumulation. Welders with higher exposure showed significantly higher R1 compared either with controls or with welders with lower exposure. Our data are additional evidence that Mn accumulation can be assessed more sensitively by R1 than by PI. Moreover, the nonlinear relationship between welding exposure and Mn brain accumulation should be considered in future studies and policies.

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.

Awareness and Utilization of Welders' Personal Protective Eye Devices and Associated Factors: Findings and Lessons From a Nigerian Population

This study assessed commercial welders' awareness and utilization of personal protective eye devices (PPEDs), and their associations, in Enugu, Nigeria, between January and March, 2011. The participants included 343 males, age 33.9 years±10.0 SD years. The participants reported high awareness of welding-associated ocular hazards (99.4%) and PPEDs (75.2%-98.3%), but low PPED possession and utilization rates. Cost and "presumed lack of utility" were the leading barriers to PPED possession; non-utilization was mainly attributed to "user inconvenience" and "presumed lack of protective benefit." PPED utilization was significantly associated with lower educational status (p=.030) and electric welding (p<.0001). The underlying causes are amenable to preventive occupational eye health education, enhanced ergonomics and affordability of PPEDs, and legislative enforcement of their use.

Prevalence and pattern of occupational injuries at workplace among welders in coastal south India

Background:

Injuries among welders are an important health issue in metal industries at global level. The study aimed to assess the prevalence and pattern of injuries and its possible associated risk factors among welders.

Materials and Methods:

A cross-sectional study was conducted among 209 welders in metal industries of Puducherry, coastal south India. Data regarding all types of injuries during the past 1 year were collected by administering a pre-designed questionnaire. The various risk factors associated with injuries that include age, training before induction, experience, job duration, tobacco chewing, alcohol use and use of protective measures were assessed using standard questionnaire. The data was analyzed by univariate and multiple logistic regression analysis.

Results:

Majority of subjects were aged between 20 and 40 years (160, 76.6%) and educated below 10^th standard (181, 86.6%). Mean number of injury was found to be 10.74 (SD = 5.74) in the preceding year. All of them had more than 2 injuries and 44% (92) of them had more than 10 injuries. All of them had abrasions and more than three fourths of them had each of lacerations, foreign body in the eye, flash burns and contusions. Multiple logistic regression analysis showed that age less than 30 years (OR = 5.19), tobacco use (OR = 2.56), alcohol use (OR = 3.96) and institutional training (OR = 0.10) were the predictors associated with more than 10 injuries among welders.

Conclusion:

Injury among welders is an important health problem in this area. Strategies for strengthening institutional training for younger age groups may help in decreasing the burden of injuries.

Respiratory health of a population of welders

Objective:

The aim was to identify respiratory symptoms and respiratory function of welders in comparison to a “nonexposed group.”

Materials and Methods:

Information was collected by means of a questionnaire completed during an interview, and spirometry of all subjects.

Results:

This study involved 41 welders and 41 comparable nonexposed group. Sixteen (39%) welders reported bringing up phlegm from the chest first thing in the morning, compared with seven individuals (17.1%) in the nonexposed group. The difference is significant (Chi-square = 3.87 odds ratio (OR) 3.11 [1.0-9.9], P = 0.0182). Eleven welders had chronic bronchitis, which they had experienced most days for as long as 3 months, compared with one person in the nonexposed group. The difference was statistically significant, and OR was 1.7 (95% confidence interval 1.19-2.53). On the other hand, the difference in cough, shortness of breath and lung function was statistically insignificant when the welders were compared with the nonexposed group.

Conclusion:

This study showed more respiratory complaints, particularly chronic bronchitis, among welders compared with the nonexposed group, which is believed to be the result of welding emissions. Spirometry showed no impairment in lung function in both the welders and the nonexposed group.

A panel study of occupational exposure to fine particulate matter and changes in DNA methylation over a single workday and years worked in boilermaker welders

BACKGROUND

Exposure to pollutants including metals and particulate air pollution can alter DNA methylation. Yet little is known about intra-individual changes in DNA methylation over time in relationship to environmental exposures. Therefore, we evaluated the effects of acute- and chronic metal-rich PM2.5 exposures on DNA methylation.

METHODS

Thirty-eight male boilermaker welders participated in a panel study for a total of 54 person days. Whole blood was collected prior to any welding activities (pre-shift) and immediately after the exposure period (post-shift). The percentage of methylated cytosines (%mC) in LINE-1, Alu, and inducible nitric oxide synthase gene (iNOS) were quantified using pyrosequencing. Personal PM2.5 (particulate matter with an aerodynamic diameter ≤ 2.5 μm) was measured over the work-shift. A questionnaire assessed job history and years worked as a boilermaker. Linear mixed models with repeated measures evaluated associations between DNA methylation, PM2.5 concentration (acute exposure), and years worked as a boilermaker (chronic exposure).

RESULTS

PM2.5 exposure was associated with increased methylation in the promoter region of the iNOS gene (β = 0.25, SE: 0.11, p-value = 0.04). Additionally, the number of years worked as a boilermaker was associated with increased iNOS methylation (β = 0.03, SE: 0.01, p-value = 0.03). No associations were observed for Alu or LINE-1.

CONCLUSIONS

Acute and chronic exposure to PM2.5 generated from welding activities was associated with a modest change in DNA methylation of the iNOS gene. Future studies are needed to confirm this association and determine if the observed small increase in iNOS methylation are associated with changes in NO production or any adverse health effect.

Respiratory morbidity among welders in the shipbuilding industry, Goa

Context:

Welding is pivotal in shipbuilding. The fumes and gases involved in welding may cause respiratory morbidity.

Aim:

To study the prevalence of respiratory morbidity (RM) among welders vis à vis among nonwelders and its association with certain relevant factors.

Settings and Design:

A cross-sectional study of 276 welders and 276 nonwelders was conducted in the shipbuilding industry.

Materials and Methods:

An interviewer-administered questionnaire was followed by spirometric examination.

Statistical Analysis:

Odds ratio and its 95% CI and two-way ANOVA.

Results:

Prevalence of RM was found to be significantly higher among welders compared to nonwelders (who were comparable in age, duration of employment (DOE) and smoking habits,) with odds ratio (OR) of 1.78 (95% confidence interval (CI):1.20-2.63). Obstructive type of RM was predominant in both welders (26% (n = 73)) and nonwelders (17% (n = 49)) with welders being at a significantly higher risk (OR = 1.66 (95%: 1.10-2.49)). RM was commoner after the 40 years of age or after 20 years of employment in both groups. Smoking was associated with RM among welders (OR = 1.48, 95% CI: 1.24-1.75) as well as nonwelders (OR = 2.83, 95% CI: 2.26-3.54). Work-related respiratory symptoms (WRRS) was not found to be related to RM (OR = 1.69, 95% CI: 1.00-2.84). Consistent use of personal protective equipment (PPE) was protective against RM in welders (OR = 0.33, 95% CI: 0.28-0.37).

Conclusion:

Welders had a greater burden of RM and this was related to increasing age, DOE, smoking and inconsistent use of PPE. WRRS were not indicative of RM.

Pattern of eye diseases among welders in a Nigeria community

BACKGROUND

Welders have been identified as a high risk group for eye disorders due to their exposure to ultraviolet radiation.

OBJECTIVE

To determine the prevalence and types of eye diseases amongst welders in Ile-Ife, Osun state.

METHODS

This is a cross sectional descriptive study of 405 consenting welders. Information on socio-demographic characteristics was obtained using a pre-tested proforma and all subjects had visual actuity test, anterior and posterior segments examination, test of stereopsis and macular function.

RESULTS

Two hundred and seventy five (67.9%) of the respondents were arc welders, 99(22.5%) were gas welders while 39(9.6%) utilized both welding techniques. The age of the respondents ranged from 16 years to 80 years with a mean of 38 ± 13 years. Conjunctival degenerative disorders like pingueculum (50.1%) and pterygium(17.5%) constituted the commonest eye disorders among the welders. There were 6 blind eyes of 5 welders with pigmentary maculopathy accounting for the single case of bilateral blindness. There is a greater odd in developing pingueculum and Pterygium (OR=1.015, 1.039 respectively) in arc welders than in gas welders.

CONCLUSION

Pingueculum, Pterygium, corneal opacity, and pigmentary macular deposits were the common eye disorders among welders.

Night heart rate variability and particulate exposures among boilermaker construction workers

BACKGROUND

Although studies have documented the association between heart rate variability (HRV) and ambient particulate exposures, the association between HRV, especially at night, and metal-rich, occupational particulate exposures remains unclear.

OBJECTIVE

Our goal in this study was to investigate the association between long-duration HRV, including nighttime HRV, and occupational PM(2.5) exposures.

METHODS

We used 24-hr ambulatory electrocardiograms (ECGs) to monitor 36 male boilermaker welders (mean age of 41 years) over a workday and nonworkday. ECGs were analyzed for HRV in the time domain; rMSSD (square root of the mean squared differences of successive intervals), SDNN (SD of normal-to-normal intervals over entire recording), and SDNN(i) (SDNN for all 5-min segments) were summarized over 24-hr, day (0730-2130 hours), and night (0000-0700 hours) periods. PM(2.5) (particulate matter with an aerodynamic diameter </= 2.5 microm) exposures were monitored over the workday, and 8-hr time-weighted average concentrations were calculated. We used linear regression to assess the associations between HRV and workday particulate exposures. Matched measurements from a nonworkday were used to control for individual cardiac risk factors.

RESULTS

Mean (+/- SD) PM(2.5) exposure was 0.73 +/- 0.50 mg/m(3) and ranged from 0.04 to 2.70 mg/m(3). We observed a consistent inverse exposure-response relationship, with a decrease in all HRV measures with increased PM(2.5) exposure. However, the decrease was most pronounced at night, where a 1-mg/m(3) increase in PM(2.5) was associated with a change of -8.32 [95% confidence interval (CI), -16.29 to -0.35] msec nighttime rMSSD, -14.77 (95% CI, -31.52 to 1.97) msec nighttime SDNN, and -8.37 (95% CI, -17.93 to 1.20) msec nighttime SDNN(i), after adjusting for nonworking nighttime HRV, age, and smoking.

CONCLUSION

Metal-rich particulate exposures were associated with decreased long-duration HRV, especially at night. Further research is needed to elucidate which particulate metal constituent is responsible for decreased HRV.

Semen quality and reproductive hormones among welders -A preliminary study

OBJECTIVES

Welders are exposed to intense heat, toxic metals and their oxides and toxic gases during welding, and some of these substances reported to have adverse effects on reproductive organs. Thus, the present study was planned to investigate the sperm quality as well as reproductive hormones among welders exposed to a complex mixture of pollutants.

METHODS

Seventeen welders aged 43.8±12.0 (mean±SD) years with welding exposure of 1 to 10 years or more participated in this study. They were performing are and gas welding in a workshop. Blood (5-6 ml) and semen samples by masturbation were collected from them. Serum was separated and analyzed for reproductive hormones by RIA techniques. Semen was processed for microscopic examination.

RESULTS

The results of this study indicated that sperm concentration was in the normal range (≥20 million/ml) in all seventeen welders, however, motility, morphology as well as Hypo Osmotic Swelling test (HOS) demonstrated impairment in few welders, indicating deterioration in sperm quality compared to the reported normal reference value. Compared with the normal value of hormones provided in diagnostic kits brochure, follicle stimulating hormone (FSH), leutinizing hormone (LH) and testosterone levels were in the normal range, except in two subjects who showed higher FSH and LH levels and one who showed a lower value of testosterone.

CONCLUSIONS

This study suggests that welding might have had some adverse effects on sperm motility, morphology and physiologic function even though sperm concentration was in the normal range. Hormonal changes did not show any definite pattern, indicating a need for further study.