With modernization, air pollution has become increasingly serious, and its effects on health have been revealed. As a result, public interest in environmental pollution has become critical for regulating air pollution. In our study, we aim to evaluate the impact of air pollution levels on public attention to environmental issues and examine whether awareness of the residential environment’s impact on health acts as a mediator in this relationship.

We conducted an analysis on 400 individuals surveyed in the preliminary feasibility study on adverse health effects in the Pohang Industrial Complex, to examine the relationship between particulate matter 2.5 (PM2.5) and attention to environmental issues. Logistic regression analysis was performed, and mediation analysis was used to determine whether awareness of the residential environment’s impact on health mediated the relationship.

The logistic regression analysis results showed that PM2.5 levels were associated with attention to environmental issues (adjusted odds ratio [AOR]: 2.1; 95% confidence interval [CI]: 1.3–3.5; p = 0.003) and awareness of health impacts (AOR: 3.4; 95% CI: 1.6–7.1; p = 0.001). The PM2.5 levels showed 9.9% (95% CI: 5.4–14.0) increase in the prevalence of high attention to environmental issues, of which, only 1.0% (95% CI: 0.2–2.3) were mediated by health impact awareness. In the overall analysis, 10% of the total effect of PM2.5 on attention to environmental issues was mediated by health impact awareness.

According to this study’s results, there was a correlation between air pollution levels and attention to environmental issues. Awareness of the health impacts of air pollution partially mediated the effect of air pollution levels on attention to environmental issues. In future studies, it is recommended to identify other mediators to further understand this structure.

This study investigated the effect of dispatch frequency on blood cadmium levels and the effect of blood cadmium levels on hypertension in male firefighters in a metropolitan city.

We conducted a retrospective longitudinal study of male firefighters who completed the regular health checkups, including a health examination survey and blood cadmium measurements. We followed them for 3 years. To investigate the effect of dispatch frequency on blood cadmium levels and the effect of blood cadmium levels on hypertension, we estimated the short-term (model 1) and long-term (model 2) effects of exposure and hypothesized a reversed causal pathway model (model 3) for sensitivity analysis. Sequential conditional mean models were fitted using generalized estimating equations, and the odds ratios (ORs) and the respective 95% confidence intervals (CIs) were calculated for hypertension for log-transformed (base 2) blood cadmium levels and quartiles.

Using the lowest category of dispatch frequency as a reference, we observed that the highest category showed an increase in blood cadmium levels of 1.879 (95% CI: 0.673, 3.086) μg/dL and 0.708 (95% CI: 0.023, 1.394) μg/dL in models 2 and 3, respectively. In addition, we observed that doubling the blood cadmium level significantly increased the odds of hypertension in model 1 (OR: 1.772; 95% CI: 1.046, 3.003) and model 3 (OR: 4.288; 95% CI: 1.110, 16.554). Using the lowest quartile of blood cadmium levels as a reference, the highest quartile showed increased odds of hypertension in model 1 (OR: 2.968; 95% CI: 1.121, 7.861) and model 3 (OR: 33.468; 95% CI: 1.881, 595.500).

We found that dispatch frequency may affect blood cadmium levels in male firefighters, and high blood cadmium levels may influence hypertension in a dose-response manner.

Firefighters are constantly exposed to harmful substances in the respiratory tract and require management measures. We comprehensively compared factors affecting the lung function of firefighters to identify management measures that can reduce the deterioration of lung function.

A cross-sectional study was conducted in 1,108 male firefighters. Subjects were surveyed with self-written questionnaires that included a history of smoking, number of workouts per week, work department, and medical history, including diseases that could affect lung function. Body mass index was calculated using an automatic body measurement instrument and body fat, body fat percentage, muscle mass, and skeletal muscle mass were measured using Inbody 770. Based on the body weight obtained from body measurements, skeletal muscle mass height-adjusted skeletal muscle index (hSMI) compared to height was determined. For lung function, forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), FEV₁/FVC, and peak expiratory flow (PEF) were measured using a spirometer HI-801. Analysis of variance and independent t-tests were performed for univariate analysis of factors that could affect lung function, and multiple regression analysis was performed for multivariate analysis.

When the factors relating lung function were analyzed using regression analysis, FEV₁ was negatively correlated with age, body fat percentage, and duty year, positively with height and hSMI. FVC increased with height and hSMI, decreased with age, body fat percentage, and duty year. FEV₁/FVC was related with age, height, body fat percentage and working history. Height and muscle mass were analyzed as related factors on PEF. When the analysis was conducted on firefighters who exercised more than 3 times a week, working history had lower relation with FEV₁ and body fat percentage had no relation with FEV₁/FVC.

We suggest management measures to reduce body fat percentage and increase skeletal muscle mass to maintain lung function in firefighters.

Noise-induced hearing loss is an occupational disease, and workplace noise exposure is a major hazard in Korea. Although hearing protectors effectively reduce a worker's exposure to noise, their success is compromised by the wearer's inability to fit the protectors correctly, and there are no proper training methods for using hearing protectors in small-scale industries. This study aims to evaluate the effect of earplug training on hearing protection using field microphone-in-real-ear (F-MIRE) and prevent noise-induced hearing loss.

The study population comprised 172 noise-exposed manufacturing workers who visited occupational health facilities in Daegu, South Korea, between July 2014 and September 2017. Personal attenuation ratings (PARs) were calculated with F-MIRE. Paired t-tests were used to compare the differences in PAR (dB) before and after training, and generalized estimating equations (GEEs) were used to compare the differences in PAR according to the number of trainings.

Mean PARs increased after the first and second training, and the differences were statistically significant. Among the 30 participants who received all 4 trainings, PARs were significantly higher after each training than before the training. As the number of training increased, the differences in PARs significantly increased. When comparing pretraining PARs for each training session, we found statistically significant differences between the first and second training and between the second and third training, but not between the third and fourth training.

In this study, the short- and long-term effects of earplug training were statistically significant. In particular, the PAR before and after the fourth training showed the greatest increase, and the PARs continued to increase during each training.

Using analysis of air samples from the workplace, we report on one case of pneumoconiosis in an individual who has been working in a polytetrafluoroethylene (PTFE) spraying process for 28 years.

The patient was diagnosed with granulomatous lung disease caused by PTFE using computed tomography (CT), lung biopsy and electron microscopy. To assess the qualitative and quantitative exposure to PTFE in workplace, Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX) and thermogravimetric analysis (TGA) were performed on air samples from the workplace. The presence of PTFE particles was confirmed, and the airborne concentration of PTFE was estimated to be 0.75 mg/m³.

This case demonstrates that long-term exposure to PTFE spraying can cause granulomatous lung lesions such as pneumoconiosis; such lesions appear to be caused not by the degradation products of PTFE from high temperatures but by spraying the particles of PTFE. Along with air-sampling analysis, we suggest monitoring the concentration of airborne PTFE particles related to chronic lung disease.

Arsenic is known as an endocrine disruptor that people are exposed to through various sources such as drinking water and indigestion of marine products. Although some epidemiological and animal studies have reported a correlation between arsenic exposure and diabetes development, there are limited studies regarding the toxic effects of organic arsenic including arsenobetaine on the human body. Here, we analyzed the association between urine arsenobetaine and the homeostasis model assessment of β-cell function (HOMA-β), which is an index for predicting diabetes development and reflecting the function of pancreatic β-cells.

In the fourth Korea National Health and Nutrition Examination Survey (KNHANES), health and nutrition surveys and screening tests were performed. Of the total survey population, people with confirmed values for urine total arsenic and arsenobetaine were included, and known diabetic patients were excluded. A total 369 participants were finally included in the study. We collected surveys on health, height, body weight, body mass index, blood mercury level, fasting glucose level, and serum insulin level and calculated HOMA index. Owing to sexual discrepancy, we performed sexually stratified analysis.

Urine total arsenic and total arsenic minus arsenobetaine was not associated with HOMA-IR and HOMA-β in univariate analysis or in sexually stratified analysis. However, urine arsenobetaine showed a statistically significant relationship with HOMA-β in univariate analysis, and only male participants showed a significant correlation in sexually stratified analysis. In the analysis adjusted for age, BMI, smoking, alcohol drinking, physical activity and blood mercury, the HOMA-β value in the group below the 25th percentile of arsenobetaine was significantly higher than the group between 50 and 75th percentile, while no difference was shown for HOMA-IR. In sexually stratified analysis, The value of HOMA-β was significantly higher in male participants with below the 25th percentile urine arsenobetaine than the group between 25 and 50th and between 50 and 75th, while no difference was shown for HOMA-IR. However, female participants did not demonstrate a relationship between HOMA–IR, HOMA-β and urine arsenobetaine.

This study revealed the association between urine arsenobetaine and pancreatic β-cell function assessed by HOMA-β in the normal population (without diabetes), especially in males, despite adjusting for factors affecting pancreatic β-cell function and diabetes.

The online version of this article (doi:10.1186/s40557-017-0181-0) contains supplementary material, which is available to authorized users.