Cancer morbidity of foundry workers in Korea

Use of micronucleus cytome assays with buccal cells for the detection of genotoxic effects: A systematic review and meta-analysis of occupational exposures to metals

Micronucleus (MN) assays with buccal cells are at present widely used to investigate occupational exposures to genotoxic carcinogens. This article describes their use for the monitoring of metal exposed workers. We found in total 73 relevant articles, in the majority (97 %) increased MN and/or other nuclear anomalies were reported. Most studies were realized in South East Asia and South America. A variety of different occupations was studied including welders, electroplaters, painters, workers in battery recycling and production, tannery workers, dental technicians, miners, workers in foundries and smelters, and also subjects working in waste recycling, glass, aluminum and steel production. In many investigations the effects increased with the duration of the working period. The quality of individual studies was evaluated with a quality score tool. The number of cells was in most studies sufficient and DNA-specific stains were used. However, many studies have shortcomings, e.g. they focused solely on MN formation and did not evaluate anomalies, which provide additional information about the stability of the genetic material and acute cytotoxic effects. Only 35 % of the investigations contain quantitative information about exposures to metals and other toxicants. In 6 of these studies, correlations were observed between the concentrations of specific metals (As, Pb, Cr, Cd) in body fluids and MN frequencies. Taken together, the available data indicate that the MN assay can be used to detect chromosomal damage in metal exposed groups; furthermore, it enables also comparisons between subgroups differing in regard to their exposure and allows an estimation of the efficiency of protective measures. The exposure of workers to metals is currently controlled with chemical analytical measurements only, MN assays with buccal cells could contribute to further improve the safety at workplaces as they reflect the biological consequences including synergistic and antagonistic interactions between toxicants.

DNA damage in foundry workers using non-invasive micronucleus cytome assay

Workers in the foundry industry are exposed to hazardous chemical agents such as metal fumes, gases, vapor of molten metal, and respirable dust and hazardous physical agents such as heat, noise, and electromagnetic fields. Co-exposures to hazardous physical and chemical agents in foundry workplaces may cause DNA damage in workers. This study aimed to evaluate DNA damage in foundry workers. Thirty-three exposed foundry workers as a exposure groups and 33 non-exposed individuals as a control groups participated in this study. Buccal micronucleus cytome (BMCyt assay) assay was used to assess DNA damage. Results showed that foundry workers were under exposure to hazardous chemical and physical agents such as metal fumes and noise. The percentage of micronucleus (MN) cells in exposure group (0.59 ± 0.93 %) were statistically higher than control group (0.23 ± 0.23 %) (P < 0.05) %). Also, the percentage of nuclear bud cells and binucleated cells in exposure group were statistically higher than control group (P < 0.05). The percentage of differentiated normal cells were significantly higher in the control group compared to the exposed group (P < 0.05). Foundry workers are at risk of DNA damage; therefore, prevention measures need to be implemented to reduce exposure to air pollutants in foundry workplaces.

Occupational exposure of foundry workers assessed by the urinary concentrations of 18 elements and arsenic species

BACKGROUND

Some raw materials applied in Fe foundry industries may contain potentially toxic elements. Thus, foundry worker's occupational exposure is a constant health concern.

METHOD

In this study, 194 urine samples from foundry workers were analyzed by inductively coupled plasma mass spectrometry for biomonitoring of Al, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, I, Mn, Ni, Pb, Sb, Sn, Se, U and Zn. Moreover, arsenic speciation was performed in representative samples of production sector workers (group A) and administration sector workers (group B).

RESULTS

Concentrations of As, Pb, Cd, Cu, Cs, I, Sb in urines from group A were higher than those found for group B. Samples of group A presented Cs, Ni, Mn, Pb, U and Zn concentrations higher than values reported for exposed workers assessed by other studies. Forty-four samples from group A exceed As-reference limits. Group A had approximately seven times more inorganic As (as arsenite) and 14 times more organic As (as dimethyl As) than group B. A statistically significant difference was observed in the elemental concentration in the workers' urine by the time in the function. Moreover, alcohol consumption is probably influencing the urine concentration of As, Ba, Cd, Co, Cu, Fe, I, Se and Zn.

CONCLUSION

The monitored foundry workers are exposed to potentially toxic elements and more attention must be given to their health. Therefore, workplace safety conditions must be improved, and constant biomonitoring is necessary to ensure workers' health.

Determination and Prediction of Respirable Dust and Crystalline-Free Silica in the Taiwanese Foundry Industry

Background: Respirable crystalline silica (RCS) has been recognized as a human carcinogen; however, the measurement and analysis of RCS in small-scale foundries is rare and difficult. This study aimed to measure respirable dust and RCS levels among 236 foundry workers in Taiwan and used these data to establish predictive models for personal exposure. Methods: Personal sampling of various production processes were measured gravimetrically and analyzed using the X-ray diffraction method. Multiple linear regression was used to establish predictive models. Results: Foundry workers were exposed to geometric means and geometric standard deviations of 0.52 ± 4.0 mg/m³ and 0.027 ± 15 mg/m³ for respirable dust and RCS, respectively. The highest exposure levels were observed among workers in the sand blasting process, with geometric means of 1.6 mg/m³ and 0.099 mg/m³ for respirable dust and RCS, respectively. The predictive exposure model for respirable dust fitted the data well (R² = 0.75; adjusted R² = 0.64), and the predictive capacity for RCS was higher (R² = 0.89; adjusted R² = 0.84). Conclusions: Foundry workers in the sand blasting process may be exposed to the highest levels of respirable dust and RCS. The developed models can be applied to predict respirable dust and RCS levels adequately in small-scale foundry workers for epidemiological studies.

Task distribution, work environment, and perceived health discomforts among Indian ceramic workers

BACKGROUND

The study examined the work environment of Indian ceramics workers and assessed associations between work hazards, work category, and self-reported symptoms.

METHODS

The multi-method ergonomic review technique (MMERT) checkpoints was used for work analysis and prevalence of self-reported symptoms among 329 male workers.

RESULTS

Ambient temperature and relative humidity in ceramic industries were 39.9°C and 17.4% respectively. Musculoskeletal discomfort was observed as a primary complaint; especially lower extremity pain (45%). Load handlers and machine operators had the highest levels of work hazards, including high skill requirement, strenuous work posture, poor commitment by the organization. Poor job autonomy, task clarity, hot workplace, inappropriate workplace design, inadequate auxiliary support, and mental overload were significantly associated with self-reported symptoms (P < 0.001).

CONCLUSION

Work categories are associated with work hazards and may lead to various health symptoms among ceramic workers. Control of workplace hazards may lower rates of symptoms and thus may lead to improved health, productivity, and well-being. Am. J. Ind. Med. 59:1145-1155, 2016. © 2016 Wiley Periodicals, Inc.

Occupational exposure to silica dust and risk of lung cancer: an updated meta-analysis of epidemiological studies

BACKGROUND

Crystalline silica is considered as one of the most common and serious occupational hazards to workers' health. Although its association with lung cancer has been studied for many decades, the conclusion remains somewhat controversial. Our objectives are to review and summarize the epidemiological evidence on the relationship between occupational silica exposure and risk of lung cancer and to provide an update on this major occupational health concern.

METHODS

Eligible studies up to 29 April 2016 were identified. Pooled effect estimates were calculated according to the reported outcome and the study design. Cohort, case control and proportional mortality studies were examined separately. Studies reporting results according to silicotic status were grouped together and analyzed. Due to the significant amount of heterogeneity expected, random effects models were implemented. Subgroup and meta-regression analyses (both univariate and multivariate) were performed in an attempt to explain heterogeneity. Studies which had adequate exposure characterization were selected to find out whether there was an exposure-response relationship between silica and lung cancer.

RESULTS

The risk of lung cancer was found to be elevated in both silicotics and non-silicotics. The pooled standardized mortality ratio (SMR) was 2.32 with a 95 % confidence interval (95 % CI) of 1.91-2.81 and 1.78 (95 % CI 1.07-2.96) respectively. The pooled standardized incidence ratio (SIR) was 2.49 (95 % CI 1.87-3.33) and 1.18 (95 % CI 0.86-1.62) respectively. Subgroup analysis showed that workers in the mining industry had the highest risk of lung cancer with a pooled SMR of 1.48 (95 % CI 1.18-1.86) and the weakest association was seen in potteries with a pooled SMR of 1.14 (95 % CI 1.05-1.23). A positive exposure-response relation was found between cumulative silica exposure and risk of lung cancer.

CONCLUSION

The results of our meta-analysis supported the carcinogenic role of silica on the lungs, which was more pronounced at higher levels of exposure, in the presence of silicosis and in the mining industry. Further research is needed to evaluate whether non-silicotics are truly at risk, whether a predisposing factor would explain this potential risk, and to determine the mechanism of carcinogenicity of silica in humans.

Occupational exposure to crystalline silica and gastric cancer: a systematic review and meta-analysis

Crystalline silica is a widely used industrial material that is readily available worldwide, and is one of the most common types of particulate mineral pollutants. It has been classified as a group 1 human carcinogen of the respiratory system; however, whether it is linked to gastric cancer remains uncertain. We conducted a systemic review and meta-analyses to search for evidence of the relationship between gastric cancer and occupational exposure to crystalline silica. We searched for articles on occupations involving silica exposure and gastric cancer studies up to December 2014. Pooled-risk estimates of the association between occupational crystalline silica exposure and risk of gastric cancer were calculated by a random effects model. Metaregression analyses of industry type and histological confirmation status, study design and industrial subgroup analyses were performed. 29 articles, including 9 case-control and 20 cohort studies, were analysed. The overall summary effects size was 1.25 (95% CI 1.18 to 1.34) for the association of occupational silica exposure with gastric cancer. Both heterogeneity and publication bias were partially attenuated after subgroup analyses. Heterogeneity of studies was attenuated after metaregression by industry. Higher overall effects were observed in the mining and foundry industries. We found a significant relationship between occupational crystalline silica exposure and gastric cancer. Our results were strengthened by various subgroup analyses and, considering the biological plausibility of our premise, further studies are required to better understand this association.

Effect of time of exposure to environmental risk on the lung function of foundry workers: a cross-sectional study

[Purpose] This cross-sectional study aimed to compare foundry workers of the metallurgical industry with high and low exposure time and with a control group. [Subject and Methods] The workers were evaluated for pulmonary function and peak expiratory flow (PEF), respiratory symptoms, smoking habits, and physical activity level. Descriptive statistical analysis and ANOVA one-way test were used. [Results] The mean age was 33.9 ± 8.25 years (18-59), pulmonary function: FVC: 95 ± 18% of predicted, FEV1: 95.0 ± 15.8% of predicted, FEV1/FVC ratio of 0.82 ± 0.09, and PEF = 499.7 ± 118.5 l/min. Overall, 85.1% of workers were classified that physically active, 7.93% of workers reported respiratory symptoms, and 14.28% reported being smokers. There was no statistically significant difference between groups for the variables of lung function. [Conclusion] The pulmonary function is preserved in foundry workers independently of exposure time.

Lung function and functional capacity among foundry workers using effective risk control measures

BACKGROUND

Inhaled dust in the environment can trigger specific reactions in the airways and cause various respiratory diseases.

OBJECTIVE

Evaluate the lung function and functional capacity of foundry workers who are exposed to metals and use effective control measures.

METHOD

A cross-sectional study was realized with 108 workers at a bronze foundry and machining plant and in maintenance at a private university, both in Brazil. The workers were divided into two groups: the study group exposed to metals but using risk control measues and a control group not exposed to metal work. The Medical Research Council Questionnaire on Respiratory Symptoms and the International Physical Activity Questionnaire were administered, and lung function and functional capacity were evaluated. Comparative statistics were used to identify differences in the outcome measures between the two groups.

RESULTS

The groups had similar personal and anthropometric characteristics and time on the job. Spirometry and peak expiratory flow presented no significant differences between the groups. And there was also no statistically significant difference between groups in functional capacity as assessed by performance on the six-minute walk test.

CONCLUSION

Foundry industry workers in Brazil who were exposed to metal but used risk control measures had similar lung function and functional capacity when compared to the control group who were not exposed to metal. This is a positive results and maybe related to age, time exposure and control of occupational hazards. However, these workers need to continue being monitored in longitudinal studies.

Increased cytogenetic abnormalities in exfoliated oral mucosal cells of South Indian foundry workers

Biomonitoring offers a valuable tool to estimate the genetic risk as of exposure to genotoxic agents. Here, we intend to assess the potential cytogenetic damage related with occupational exposure to polycyclic aromatic hydrocarbons by evaluating the genetic damages in exfoliated buccal epithelial cells of foundry workers via counting micronucleus (MNs) and other nuclear abnormalities (NAs). This was a cross-sectional study and all study subjects were male . Exfoliated buccal mucosal cells were obtained from 100 subjects involved in either foundry molding or melting processes, and 100 controls matched for sex, age, and smoking from the area of Coimbatore city, Southern India. For each individual, 2000 exfoliated buccal cells were analyzed. Significantly, there was a higher frequency of MN in the exposed workers than in the controls (P < 0.05). Smoking was associated with the increased frequencies of micronuclei and NAs in the buccal epithelium of both the control and the exposed groups. Smoking represented significant factors in terms of increasing the production of MN when the control and the exposed groups were compared (P < 0.05). The results specify that buccal cells of foundry workers display increased levels of genotoxicity and these biomarker responses may be related to the increased cancer risk. These results conclude that the studied individuals are at a risk group and they require periodical biological monitoring and proper care which is essential for them.

Assessment of Occupational Exposure to Dust and Crystalline Silica in Foundries

BACKGROUND

The term "crystalline silica" refers to crystallized form of SiO2 and quartz, as the most abundant compound on the earth's crust; it is capable of causing silicosis and lung cancer upon inhaling large doses in the course of occupational exposure. The aim of this study was to assess occupational exposure to dust and crystalline silica in foundries in Pakdasht, Iran.

MATERIALS AND METHODS

In this study, airborne dust samples were collected on PVC filters (37 mm diameter, 0.8 mm pore size), by using a sampling pump and open face cyclone at a flow rate of 2.2 l/min for a maximum volume of 800 liters. For determining crystalline silica spectrometry was used according to the National Institute of Occupational Safety and Health (NIOSH) method No. 7601 for analysis of samples.

RESULTS

Results showed that crystalline silica concentration was higher than NIOSH and the American Conference of Government Industrial Hygienist (ACGIH) allowed extent (0.025 mg/m(3)). Concentration of crystalline silica was 0.02-0.1 mg/m(3). Total dust concentration average was higher than the allowed extent by Permissible Exposure Limit (PEL) of the Occupational Safety and Health Administration (OSHA).

CONCLUSION

It is essential to take necessary measures to control crystalline silica dust regarding the fact that 50% of workers are exposed to higher than the allowed extent.

Epidemiologic characteristics of compensated occupational lung cancers among Korean workers

An understanding of the characteristics of occupational lung cancer is important to establish policies that prevent carcinogen exposure and to compensate workers exposed to lung carcinogens. This study analyzed the characteristics of occupational lung cancers in workers who were compensated under the Industrial Accident Compensation Insurance Law between 1994 and 2011. A total of 179 occupational lung cancers were compensated. The main carcinogenic exposure was asbestos, followed by crystalline silica and hexavalent chromium. The mean exposure duration and latency were 19.8 and 23.2 yr. The most common industry was manufacturing, followed by construction and transportation. The most common occupation was maintenance and repair, followed by foundry work, welding, painting, and spinning or weaving. Although asbestos was predominant carcinogen, the proportion of these cases was relatively low compared to other developed countries. Proper surveillance system is needed to monitor occupational lung cancer and improve prevention measures.

Cause-specific mortality due to malignant and non-malignant disease in Korean foundry workers

BACKGROUND

Foundry work is associated with serious occupational hazards. Although several studies have investigated the health risks associated with foundry work, the results of these studies have been inconsistent with the exception of an increased lung cancer risk. The current study evaluated the mortality of Korean foundry workers due to malignant and non-malignant diseases.

METHODS

This study is part of an ongoing investigation of Korean foundry workers. To date, we have observed more than 150,000 person-years in male foundry production workers. In the current study, we stratified mortality ratios by the following job categories: melting-pouring, molding-coremaking, fettling, and uncategorized production work. We calculated standard mortality ratios (SMR) of foundry workers compare to general Korean men and relative risk (RR) of mortality of foundry production workers reference to non-production worker, respectively.

RESULTS

Korean foundry production workers had a significantly higher risk of mortality due to malignant disease, including stomach (RR: 3.96; 95% CI: 1.41-11.06) and lung cancer (RR: 2.08; 95% CI: 1.01-4.30), compared with non-production workers. High mortality ratios were also observed for non-malignant diseases, including diseases of the circulatory (RR: 1.92; 95% CI: 1.18-3.14), respiratory (RR: 1.71; 95% CI: 1.52-21.42 for uncategorized production worker), and digestive (RR: 2.27; 95% CI: 1.22-4.24) systems, as well as for injuries (RR: 2.36; 95% CI: 1.52-3.66) including suicide (RR: 3.64; 95% CI: 1.32-10.01).

CONCLUSION

This study suggests that foundry production work significantly increases the risk of mortality due to some kinds of malignant and non-malignant diseases compared with non-production work.

Prevalence of occupational asthma and respiratory symptoms in foundry workers

This cross-sectional study was conducted in a foundry factory to assess the prevalence of respiratory symptoms and occupational asthma in foundry workers. Physical examination, spirometric evaluation, chest radiograph, and a questionnaire related to respiratory symptoms were performed. Monitoring of peak expiratory flow rates, spirometric reversibility test, and high-resolution computed tomographies were performed for the participants having respiratory symptoms and/or impaired respiratory function test. A total of 347 participants including 286 workers from production department and 61 subjects who worked in nonproduction departments were enrolled in this study. It is found that phlegm (n: 71, 20.46%) and cough (n: 52, 14.98%) were the most frequent symptoms. The other symptoms were breathlessness (n: 28, 8.06%), chest tightness (n: 14, 4.03%), and wheezing (n: 7, 2.01%) . The prevalence of occupational asthma was found to be more frequent among the subjects who worked in the production department (n: 48, 16.78% ) than the other persons who worked in the nonproduction department (n: 3, 4.91%) by chi-square test (P: 0.001). To prevent hazardous respiratory effects of the foundry production, an early diagnosis of occupational asthma is very important. Cessation of cigarette smoking and using of protective masks during the working time should be encouraged.

Status of neurocognitive and oxidative stress conditions in iron–steel workers

The aim of this study was to determine oxidative stress status as well as ferrous (Fe) and Copper (Cu) levels in blood, neurocognitive impairment, and clinical markers in iron–steel workers. A comparative cross-sectional analysis was performed in 50 iron–steel workers who have been in contact with Fe and Cu in comparison with a control group containing 50 healthy subjects in the same age group and sex. Blood levels of lipid peroxidation, total antioxidant capacity, Fe, and Cu along with neurocognitive impairment were measured in workers and controls. Clinical examination was accomplished to record any abnormal sign or symptoms. Comparing with controls, the workers showed higher blood levels of lipid peroxidation and Cu and also a lower total antioxidant capacity. There was a positive correlation between work history and interstitial lung disease that strengths the presumption to progress to chronic obstructive lung disease in future. The results indicate that exposure to a combination of Fe and Cu in iron–steel workers induces oxidative stress. Especially, in the present case, toxic effect of Cu has been more than positive effects of Fe, but the combined exposure resulted in no such critical toxicity.

Two Cases of Lung Cancer in Foundry Workers

Background

Iron and steel foundry workers are exposed to various toxic and carcinogenic substances including crystalline silica, polycyclic aromatic hydrocarbons, and arsenic. Studies have been conducted on lung cancer in iron and steel founding workers and the concentration of crystalline silica in foundries; however, the concentration of crystalline silica and cases of lung cancer in a single foundry has never been reported in Korea. Therefore, the authors report two cases of lung cancer and concentration of crystalline silica by the X-ray diffraction method.

Case presentation

A 55-year-old blasting and grinding worker who worked in a foundry for 33 years was diagnosed with lung cancer. Another 64-year-old forklift driver who worked in foundries for 39 years was also diagnosed with lung cancer. Shot blast operatives were exposed to the highest level of respirable quartz (0.412 mg/m³), and a forklift driver was exposed to 0.223 mg/m³.

Conclusions

The lung cancer of the two workers is very likely due to occupationally related exposure given their occupational history, the level of exposure to crystalline silica, and epidemiologic evidence. Further studies on the concentration of crystalline silica in foundries and techniques to reduce the crystalline silica concentration are required.

Laryngeal cancer and silica dust exposure: a systematic review and meta-analysis

BACKGROUND

Individual epidemiological studies generally lack the power to examine the association between silica exposure or silicosis and laryngeal cancer. We summarized pertinent evidence from published literature by using meta-analysis.

METHODS

A systematic literature search was performed to identify cohort and case-control studies, and the method of meta-analysis was used to combine standardized mortality ratios (SMRs) or standardized incidence ratios (SIRs) from cohort studies and odds ratios (ORs) from case-control studies.

RESULTS

A significantly increased risk of laryngeal cancer (pooled OR = 1.39, 95% confidence interval (95% CI): 1.17-1.67) among workers exposed to silica dust was observed by combining six case-control studies with adjustment for smoking and alcohol consumption. A similarly increased but statistically non-significant risk estimate was observed from cohort studies, with a pooled SMR of 1.38 (95% CI: 0.79-1.96) for silicosis cases; and a pooled SMR of 1.13 (95% CI: 0.82-1.45) and a pooled SIR of 1.50 (95% CI: 0.59-2.42) for workers with silica dust exposure.

CONCLUSION

This systematic review demonstrated a weak association between silica or silicosis and laryngeal cancer. Owing to the inherent limitations of the original studies, interpretation of the results of this meta-analysis should be cautious.