Recently, there has been increasing worldwide concern about outdoor air pollution, especially particulate matter (PM), which has been extensively researched for its harmful effects on the respiratory system. However, sufficient research on its effects on cardiovascular diseases, such as hypertension, remains lacking. In this study, we examine the associations between PM levels and hypertension and hypothesize that higher PM concentrations are associated with elevated blood pressure.

A total of 133,935 adults aged ≥ 40 years who participated in the Korean Genome and Epidemiology Study were analyzed. Multiple linear regression analyses were conducted to investigate the short- (1–14 days), medium- (1 and 3 months), and long-term (1 and 2 years) impacts of PM on blood pressure. Logistic regression analyses were conducted to evaluate the medium- and long-term effects of PM on blood pressure elevation after adjusting for sex, age, body mass index, health-related lifestyle behaviors, and geographic areas.

Using multiple linear regression analyses, both crude and adjusted models generated positive estimates, indicating an association with increased blood pressure, with all results being statistically significant, with the exception of PM levels over the long-term period (1 and 2 years) in non-hypertensive participants. In the logistic regression analyses on non-hypertensive participants, moderate PM₁₀ (particulate matter with diameters < 10 μm) and PM_2.5 (particulate matter with diameters < 2.5 μm) levels over the long-term period and all high PM₁₀ and PM_2.5 levels were statistically significant after adjusting for various covariates. Notably, high PM_2.5 levels of the 1 year exhibited the highest odds ratio of 1.23 (95% confidence interval: 1.19–1.28) after adjustment.

These findings suggest that both short- and long-term exposure to PM is associated with blood pressure elevation.

Environmental exposure is characterized by low concentration, chronic, and complex exposure. Traditional epidemiological studies show limitations in reflecting these characteristics since they usually focus on a single or very limited number of exposure factors at a time. In this study, we adopted the methodology of environment-wide association study (EWAS) to figure out the association of human liver function with various environmentally hazardous substances.

We analyzed 2,961 participants from the Korean National Environmental Health Survey Cycle 4 (2018–2020). Using generalized linear model (GLM) analysis, we analyzed the association of 72 variables with 3 liver function indices (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and gamma glutamyl transferase [GGT]). Finally, we visualized our results with Manhattan plot.

In GLM analysis, perfluorooctanesulfonate were positively associated with ALT (odds ratio [OR]: 2.2; 95% confidence interval [CI]: 1.39–3.46; p _adjusted = 0.0147) and perfluorodecanoic acid showed positive association with GGT (OR: 2.73; 95% CI: 1.36–5.5; p _adjusted = 0.0256). Plasma mercury showed positive association with GGT (OR: 1.45; 95% CI: 1.14–1.84; p _adjusted = 0.0315). Using a plastic container while keeping food in the refrigerator was associated with elevated GGT compared to using a glass container (OR: 1.51; 95% CI: 1.16–1.95; p _adjusted = 0.0153). 2-ethyl-5-oxohexyl phthalate, showed a negative trend with all 3 indices, with AST (OR: 0.54; 95% CI: 0.39–0.73; p _adjusted = 0.00357), ALT (OR: 0.5; 95% CI: 0.34–0.75; p _adjusted = 0.036), GGT (OR: 0.55; 95% CI: 0.4–0.76; p _adjusted = 0.00697). Bisphenol S and frequent use of sunblock cream showed negative association with ALT (OR: 0.77; 95% CI: 0.66–0.89), and GGT (OR: 0.25; 95% CI: 0.11–0.55), respectively.

We conducted an exploratory study on environmental exposure and human liver function. By using EWAS methodology, we identified 7 factors that could have potential association with liver function.

Mental health problems are emerging issues in occupational safety and health, whereas the findings on the relationship between physical hazards and mental health are not consistent. The aim of our study was to investigate the association between physical hazard exposure and mental health outcomes including depression and anxiety.

We included 48,476 participants from the fifth Korean Working Conditions Survey (KWCS) in this study. The χ² test and logistic regression analyses were conducted to assess the association between physical hazard exposures and mental health. All statistical analyses were performed sex-specifically.

In logistic regression analysis, the odds ratios (ORs) of depression were significantly increased in male workers who were exposed to vibration (severe OR: 1.54, 95% confidence interval [CI]: 1.21–1.95) and noise (severe OR: 1.93, 95% CI: 1.49–2.48) whereas the ORs of depression were not significant in female workers from vibration (severe OR: 0.86, 95% CI: 0.50–1.38) or noise exposure (severe OR: 1.39, 95% CI: 0.84–2.17). The ORs of anxiety were significantly increased in male workers with vibration (severe OR: 1.76, 95% CI: 1.43–2.15) and noise exposure (severe OR: 2.12, 95% CI: 1.69–2.63) whereas the OR between vibration and anxiety (severe OR: 1.45, 95% CI: 0.91–2.21) was not significant in female workers. High or low temperature exposure had significant associations with depression and anxiety in both male and female subjects.

Results of our study suggest that physical hazard exposures may be associated with increased risk of mental health problems including depression and anxiety. These associations are more prominent in male workers in comparison with female workers.

Phthalates are one of renowned endocrine-disrupting chemicals, although inconsistent results are present around their effect on onset of menarche. Our hypothesis is that pre-pubertal exposure to phthalates is associated with acceleration of menarche.

We analyzed a total of 236 middle school (7th to 9th grade) girls from Korean National Environmental Health Survey 2015–2017. We used multiple linear regression to investigate impact of eight phthalate metabolites on age of menarche. We also conducted logistic regression to evaluate association between phthalate metabolite concentrations and early onset of menarche, adjusting for grade, maternal age of menarche and body mass index (BMI).

In linear regression analysis, no significant association was found for any phthalate metabolites. In logistic regression analysis, however, odds ratios (ORs) of early menarche were significantly increased for mono-n-butyl phthalate (MnBP) and for sum of all phthalates. When compared to group with the lowest level, high concentration group for MnBP presented significantly increased odds of early menarche (OR: 2.09; 95% confidence interval [CI]: 1.03, 4.23) after adjusting for grade, maternal age of menarche and BMI. Furthermore, high concentrations of sum of all phthalates were associated with significant increase of OR of early menarche (OR: 2.22; 95% CI: 1.10, 4.49) after adjustment, compared to the lowest concentration group.

Results of our study suggest that exposure to phthalates around puberty may be associated with increased risk of early menarche.

Rhinitis was the most frequently diagnosed disorder among users of humidifier disinfectants (HDs). The aim of our study was to investigate on the relationship between allergic rhinitis (AR) and HD uses.

Our study used the data from the eighth Panel Study on Korean Children; a total of 1,540 participants were enrolled. The χ² test and multiple logistic regression analyses were conducted to debunk the association between AR and HD uses.

In our analysis, odds ratios (ORs) of doctor-diagnosed AR increased significantly when simply the response of whether HDs were used in the past was considered. When the brands of HD were considered, ORs of doctor-diagnosed AR were found to be increased significantly for those who have used polyhexamethylene guanidine phosphate/oligo(2-[2-ethoxy]-ethoxyethyl)guanidinium-containing HDs (model 3: 1.41, 95% confidence interval [CI]: 1.02–1.95). However, once duration of usage was additionally considered, ORs of doctor-diagnosed AR increased significantly only for those who have used chloromethylisothiazolinone/methylisothiazolinone-containing HDs for more than or equal to 3 months (model 3: 2.08, 95% CI: 1.17–3.69). Further, past use of HD was associated with significantly increased ORs of AR diagnosed before 2013 (model 3: 1.35, 95% CI: 1.02–1.79).

Results of our study suggest that past uses of HDs may be associated with an increased risk of AR.

Depression is considered as a risk factor for cardiovascular disease (CVD) and associated with changes in individuals' health status that might influence CVD risk. However, most studies have scrutinized this relationship on a rather narrower and specific study population. By focusing on general population of Korea, we sought to inspect the association of depression with CVD risk and cardiovascular risk factors.

The data from the first year (2016) of the 7th Korea National Health and Nutrition Examination Survey was used. Participants were classified by the Patient Health Questionnaire-9 (PHQ-9) score as such: normal group (PHQ-9 score 0–4), mild depression (MD) group (PHQ-9 score 5–9) and moderate and severe depression (MSD) group (PHQ-9 score 10–27). General linear model was used to analyze differences and the trend of mean CVD risk according to depression level. Adjusted odds ratios (AORs) were calculated by logistic regression to identify the association between depression and cardiovascular risk factors after adjusting for age.

Mean CVD risk of MSD group was higher than that of normal group (p < 0.05). There was a tendency of CVD risk to increase as depression worsened (p < 0.01). Among men, MSD group was associated with current smoking (AOR, 2.97; 95% confidence interval [CI], 1.78–4.97), taking antihypertensive medications (AOR, 2.42; 95% CI, 1.26–4.66), increased fasting blood sugar (> 125 mg/dL; AOR, 2.37; 95% CI, 1.25–4.50) and taking diabetes medications (AOR, 3.08; 95% CI, 1.65–5.72). MD group was associated with current smoking (AOR, 1.60; 95% CI, 1.18–2.17). Among women, MSD group was associated with high body mass index (≥ 25 kg/m²; AOR, 1.61; 95% CI, 1.11–2.32), large waist circumference (≥ 85 cm; AOR, 1.63; 95% CI, 1.12–2.37), current smoking (AOR, 5.11; 95% CI, 3.07–8.52) and taking diabetes medications (AOR, 2.62; 95% CI, 1.68–4.08). MD group was associated with current smoking (AOR, 1.86; 95% CI, 1.18–2.93).

We suggest that depression is associated with increased risk for CVD occurrence in general population of Korea.

Shift work is associated with a higher risk of cardiovascular diseases. Here, we sought to assess the relationship between shift work and plasma homocysteine levels. Determining the correlations between shift work and homocysteine levels may provide a better understanding of the mechanisms underlying cardiovascular diseases.

This study was performed using data from routine health examinations of steel workers in 2017. In total, 431 male workers (70 daytime workers and 361 shift workers) employed on a rolling departure schedule were recruited. Plasma homocysteine levels > 15 μmol/L were considered elevated. The χ², analysis of variance, and multiple logistic regression analyses were used to examine the association between shift work and plasma homocysteine levels.

In comparison to daytime workers, the odds ratio (OR) of hyperhomocysteinemia in individuals with < 10 years of shift work was 1.14 (95% confidence interval [CI]: 0.64–2.03), compared to 2.01 (95% CI: 1.14–3.54) for workers with ≥ 10 years of experience. After adjusting for confounding variables, the adjusted OR for shift workers with < 10 years of experience was 0.95 (95% CI: 0.50–1.80), compared to 2.00 (95% CI: 1.07–3.74) for workers with ≥ 10 years of experience.

The risk of hyperhomocysteinemia was significantly higher in shift workers compared to those working normal daytime hours, particularly among long-term shift workers.