Background: Depression substantially impacts on quality of life, personal relationships, and self-care. Gastrointestinal disorders are the common comorbidity of depression and 24.3% of patients with depression have disordered bowel habits. Dietary intake of live microbes alters the host’s microflora and is beneficial for the prevention and control of bowel health and depression. We aim to investigate the association of dietary intake of live microbes with bowel health and depression and to further examine weather bowel health or depression mediates the therapeutic effect of live microbes.

Methods: Participants’ data were obtained from the National Health and Nutrition Examination Survey (NHANES) 2005–2010, which is designed to examine the health and nutritional status of the non-institutionalized US population by a complex, multi-stage, probability sampling design. The foods were grouped into categories on the basis of estimated microbial levels: low (<10⁴ CFUs/g), medium (Med; 10⁴–10⁷ CFU/g), and high (Hi; >10⁷ CFU/g). Participants were further classified into three groups (G1: participants without MedHi foods intakes; G2: those with MedHi foods intakes greater than zero but less than the median; and G3: those with MedHi foods intakes greater than the median).

Results: A total of 10,785 US adults were selected. The median of MedHi foods intake was 66.1 g/day. Participants in the G2 (OR = 0.739, 95% CI: 0.581–0.941) and G3 (OR = 0.716, 95% CI: 0.585–0.877) groups had significant association with lower risks of depression, and participants in the G3 group had significant association with lower risks of hard stools (OR = 0.885, 95% CI: 0.692–0.989) and loose stools (OR = 0.769, 95% CI: 0.585–0.954). Interestingly, further mediation analyses showed that the association of dietary live microbe intake with depression is mediated by the stool types, and the association of dietary live microbe intake with stool types is mediated by the depression (all P < 0.05).

Conclusions: A high dietary intake of live microbes, especially a minimum of 66.1 g of MedHi foods per day, is associated with a lower risk of depression, hard stools, and loose stools consistency. Depression and bowel health mutually act as mediators in this association, indicating dietary intake of live microbes may simultaneously affect bowel health and depression.

Background: Chronic arsenite exposure has been known to induce cancer in various organs; however, the underlying mechanisms remain elusive. The characteristic feature of carcinogenesis due to arsenic exposure is that the disease develops after a prolonged latent period, even after cessation of exposure. Our previous study revealed that arsenite exposure induces premature senescence in hepatic stellate cells and suggests that the senescence-associated secretory phenotype (SASP) factors from the senescent cells promote hepatic carcinogenesis. However, arsenite exposure in the liver occurs not only in hepatic stellate cells, but also in hepatocytes. Therefore, we examined whether arsenite exposure in hepatocytes also causes premature senescence and the enhancement of SASP factors. We also assessed whether those effects remained after cessation of arsenite exposure.

Methods: Human hepatocyte-derived cell line Huh-7 was exposed to sodium arsenite for 72 hours to determine the concentration at which cell proliferation was inhibited. In the 5 µM of exposure, various cellular senescence markers and SASP factors were analyzed and compared with unexposed cells. We also examined whether those senescence markers and SASP factors were maintained after cessation of arsenite exposure. Finally, we explored whether the increased expression of SASP factor, which was upregulated in hepatocytes by arsenic exposure in this study, is related to the prognosis of human hepatocellular carcinoma.

Results: After exposure to 5 µM of sodium arsenite for 72 hours, various senescent features, such as the induction of P21 mRNA, the reduction of LAMINB1 mRNA, morphological changes, phosphorylation of P53, and the presence of SA-β-gal positive cells were observed. Those changes were maintained after cessation of arsenite exposure. In addition, mRNA levels of SASP factors (MMP1, MMP3, MMP10, GDF15, PAI-1, and IL-6) were increased after arsenite exposure, and their high expression levels were maintained after cessation of arsenite exposure. Furthermore, by analyzing the TCGA database, we found that the increased expression levels of many SASP factors negatively correlated with prognosis.

Conclusions: Arsenite exposure induces premature senescence in hepatocyte-derived cells and increases SASP factors that are related to hepatic tumorigenesis. Once arsenite exposure induces premature senescence, the senescent cells remain even after cessation of exposure.

Background: Artificial light at night (ALAN) has been increasingly recognized as a potential environmental risk factor for mental health issues. However, no meta-analyses have been conducted to summarize the findings. This study aimed to evaluate the pooled associations between outdoor and indoor ALAN exposures and the risk of depression.

Methods: Adhering to the PRISMA guideline, we conducted systematic searches across PubMed, Web of Science, EMBASE, Cochrane, and Ovid databases for studies published before May 1st, 2024.

Results: A total of 7 studies (5 for outdoor ALAN and 2 for indoor ALAN) with a combined total of 560,219 participants were included in the meta-analysis. Specifically, a 1 nW/cm²/sr increase in outdoor ALAN was associated with a 0.43% (95% CI: 0.21%, 0.65%) increase in depression risk. Meanwhile, a 1 lux increase in indoor ALAN was associated with a 3.29% (95% CI: 0.85%, 5.79%) increase in depression risk. No potential heterogeneity was observed for outdoor ALAN exposure and indoor ALAN exposure. Subgroup analyses for outdoor ALAN indicated that development level, sample size, age group, sex, study design, modality of depression assessment, or adjustment of sleep-related variables in models may not be potential sources of heterogeneity. Sensitivity analyses confirmed the robustness of the findings, while evidence of publication bias was observed for studies on outdoor ALAN.

Conclusions: Our findings suggest that both outdoor and indoor ALAN exposures are associated with increased risk of depression. These results underscore the importance of considering outdoor and indoor ALAN in public health strategies aimed at reducing depression risk. Nevertheless, further studies with prospective design are still warranted considering the limited study numbers.

Background: Low birth weight (LBW) is an important public health issue that affects development and health over a long period. However, there has been no sufficient decrease in the prevalence of LBW, and it is important to identify preventable factors for LBW which remain to be clarified. The purpose of this study was to clarify the association between Internet use for many hours during pregnancy and LBW.

Methods: The subjects were mothers who had submitted the pregnancy notification form in Matsue City between April 2016 and September 2017 and their children. The data provided by Matsue City authorities consisted of 2,465 records. We analyzed 2,089 records, excluding untraceable records, those with insufficient information, those on multiple pregnancy, and those on pregnant smokers. Logistic regression analysis was performed using LBW as a dependent variable, Internet use for many hours during pregnancy as an independent variable, and the child’s sex, mother’s age at the time of pregnancy, unmarried status on pregnancy, first childbirth, mother’s job during pregnancy, and weeks of pregnancy on the notification as covariates.

Results: The results of analysis showed that Internet use for many hours during pregnancy accounted for 4.4%, and that LBW accounted for 7.2%. Internet use for many hours during pregnancy was associated with LBW (adjusted odds ratio = 2.16 (95%CI: 1.13–4.13)).

Conclusions: This study suggested that there is an association between Internet use for many hours during pregnancy and LBW. It is necessary to provide appropriate support to pregnant women who use the Internet for many hours during pregnancy after confirming the presence or absence of risk factors for LBW.

Background: Vascular intestinal disease is a major health concern that often requires emergency surgery in patients with intestinal obstruction, perforation, or bowel necrosis. We aimed to provide data on the incidence, prevalence, mortality and disability-adjusted life years (DALYs) of vascular intestinal diseases from 1990 to 2021, thereby contributing to the development of health policies.

Methods: Using standardized methods from the 2021 Global Burden of Disease study, we analyzed the incidence, prevalence, mortality, and DALYs of vascular intestinal disease from the perspectives of the sociodemographic index (SDI), regional, and country, along with the corresponding estimated annual percentage changes. Additionally, we used join-point regression to identify the key time points for disease burden changes.

Results: In 2021, a total of 169,432 cases [95% uncertainty interval (UI): 155,127–185,189] of vascular intestinal disease were identified worldwide. The age-standardized incidence rate decreased from 18.81 (95% UI: 16.07–21.73) in 1990 to 15.98 (95% UI: 13.99–19.10) in 2021. In 2021, the age-standardized mortality rate was 1.12/100,000 people (95% UI: 1.00–1.21). Over the 32-year period, the global DALYs rate declined by 1.44 (95% Confidence Interval: −1.55 to −1.34). Within the five SDI regions, the high-middle SDI areas recorded the peak standardized mortality rates in 2021. Regionally, the greatest increase in incidence occurred in North Africa and the Middle East. Canada recorded the greatest national incidence rate [58.35 (95% UI: 50.05–67.37)] in 2021 among 204 countries, while Russia exhibited the highest related mortality [5.64/100,000 people (95% UI: 5.19–6.11)] and DALYs rate [101.48/100,000 people (95% UI: 93.83–109.66)].

Conclusions: Despite a global decline in the burden of vascular intestinal disease from 1990 to 2021, significant regional and national disparities persist and the disease burden among the elderly has increased.

Background: Cardiovascular disease (CVD) is the leading cause of death worldwide. Few studies have investigated the effects of mixed polycyclic aromatic hydrocarbon (PAH) exposure on CVD prevalence. We aimed to evaluate the association between mixed PAHs exposure and CVD and determine the extent to which these links are mediated by inflammatory indices.

Methods: We used National Health and Nutrition Examination Survey (NHANES) data from 2003 to 2016. Adults with a diagnosis of CVD and seven monohydroxylated PAH metabolites (OH-PAHs) in their urine samples were included. Multivariate logistic regression and Bayesian kernel machine regression (BKMR) models were used to estimate the association between single and mixed PAHs exposure and CVD. Mediation analysis was used to evaluate the mediating effect of inflammatory indices on the association between PAHs mixtures and CVD.

Results: Here, 9136 individuals were included and 10.5% had CVD. Multivariate logistic regression analysis with all the OH-PAHs included that 2-hydroxyfluorene was found positively associated with increased odds of CVD. The BKMR analysis revealed that the overall effect of the seven PAH mixtures was positively associated with CVD. The univariate exposure-response function showed that 2-hydroxyfluorene was positively associated with CVD. Moreover, mediation analysis demonstrated that neutrophil-to-lymphocyte ratio and systemic immune inflammation index mediated the association between PAHs and CVD.

Conclusions: Our findings highlight the complexity of the association between mixed PAHs exposure and CVD. At the same time, our study provides insight into the potential mechanisms of inflammation as a mediator between exposure to PAH mixtures and CVD.

The extensive number of publications on suicide risk factors presents a practical challenge for clinicians, policy makers, and researchers to translate the research findings from academia to the improvement of individual suicide predictions and collective prevention. The Suicide Risk-Factor – Data Query Tool (SURF-DTQ) is a web application that collates organized data and helps with meta-analysis of suicidality data. Through a process of systematic review of literature according to PRISMA standards, screening and extracting studies with designs of a high level of evidence, and multi-level data synthesis, information is presented in the SURF database in a summarized, structured, and immediately relevant form. SURF allows users to search by risk factor, population, date, and indicator filters, enabling users to quickly access the most up to date and empirically grounded general or specific knowledge about suicide-related risk factors.

Background: Current experimental evidence supports that ethylene oxide (EO) exposure-related pathophysiologies may affect glucose metabolism, but few population-based studies have explored the potential links.

Methods: This study used cross-sectional data from 15560 participants in the National Health and Nutrition Examination Survey (NHANES) from 2017 to 2020. EO exposure levels were calculated by testing hemoglobin adducts of EO (HbEO) via a modified Edman reaction. We focused on the association of EO exposure with prediabetes and diabetes as well as indicators of impaired glucose metabolism and further analyzed the potential pathogenic mechanisms. Statistics included logistic regression, generalized additive model fitting, penalized spline method, two-piecewise linear regression, recursive algorithm, mediation analysis, and Pearson’s analysis.

Results: EO exposure was associated with changes in glucose metabolic indicators and increased prevalence of prediabetes and diabetes, showing age-consistency and being more pronounced in obese and non-smoking populations. For each one pmol/g Hb, one SD, or two-fold SD increase in log2-HbEO, the risk of prediabetes increased by 12%, 16%, and 33%, with an increased risk of diabetes by 18%, 26%, and 61%, respectively. Dose-response curves revealed that this positive correlation was approximately linear with prediabetes and “J” shaped with diabetes. When log2-HbEO > 8.03 pmol/g Hb, the risk of diabetes would be further increased. Pearson’s correlation revealed that EO exposure was associated with reduced fasting insulin and elevated HbA1c in the prediabetic stage. While in the diabetes stage, EO exposure was correlated with elevated fasting glucose, HbA1c, and HOMA-IR, suggesting an exacerbation of diabetes progression by EO exposure. A potential mechanism that the early stages of impaired glucose metabolism may be initiated by EO-related inflammation and oxidative stress damaging pancreatic β-cells, resulting in decreased insulin secretion. These speculations were partially supported by mediation analysis and mediators’ Pearson analysis.

Conclusion: Elevated ethylene oxide exposure increases the incidence of impaired glucose metabolism in the general U.S. population and a potential intervention may be to effectively suppress inflammation and oxidative stress imbalances.

Background: The association between air pollution and an increased risk of cardiovascular diseases, including stroke, is well-established. However, it remains unclear how reductions in pollutant levels—resulting from clean air policies and the COVID-19 lockdown—affect this relationship.

Methods: A time-series study was conducted using data from Shanghai, China, spanning from 2013 to 2022, divided into two periods (2013–2019 and 2020–2022). Daily air pollution data were obtained from China’s air quality platform, while stroke emergency department (ED) visits were sourced from Renhe Hospital. We employed quasi-Poisson regression to analyze the relationship between daily pollutant levels and stroke ED visits, with stratified analyses by sex, age, season, and period. The study identified significant reductions in six pollutants (PM_2.5, PM_10–2.5, PM₁₀, SO₂, NO₂, CO) during the 2020–2022 period compared to 2013–2019.

Results: Significant reductions in six air pollutants (NO₂, PM_2.5, PM_10–2.5, PM₁₀, SO₂, CO) were observed during 2020–2022 compared to 2013–2019. Higher daily NO₂ levels were associated with an increased risk of stroke and its subtypes throughout the study, with a stronger correlation observed in the 2020–2022 period (P < 0.001). Subgroup analyses indicated that females and individuals aged 65–74 experienced the highest risks. The elevated stroke risk was particularly pronounced in the summer during 2020–2022. A two-factor model demonstrated that combined exposure to NO₂ and other pollutants increased stroke risk.

Conclusions: This study heightened that reduced NO₂ levels generally mitigate the adverse effects of short-term exposure to air pollutants on stroke risk, although the benefits vary among subgroups. The persistent stroke risk despite lower pollutant levels underscores the complex factors influencing stroke risk, highlighting the need for comprehensive intervention strategies.

Background: Cleft lip and/or palate (CL/P) is one of the most frequent craniofacial disorder which could associate with a wide range of craniofacial complication. In order to perform comprehensive care of CL/P patients, it is crucial to elucidate the link of CL/P and general clinical conditions. This study aims to elucidate the relationships between medical history of different CL/P types and infectious diseases to serve as a reference for the comprehensive care of patients with CL/P.

Methods: We investigated the association between a history different types of CL/P and the risk of infectious diseases among 1-year old children in the Japan Environment and Children’s Study (JECS). Among the 104,065 registered fetal records, 92,590 eligible participants were included in the analysis.

Results: The multivariable-adjusted risk ratios (95% confidence intervals) for otitis media were increased in cleft lip and palate (CLP) and cleft palate only (CPO) groups by 3.81 (2.73–5.31) and 2.27 (1.22–4.22), respectively. The prevalence of Upper respiratory inflammation (URTI) was not associated with CLP, cleft lip only, or CPO. However, analysis in all groups showed a higher risk of URTI compared with the control group (1.31 [1.04–1.66]).

Conclusions: CL/P care requires additional attention to prevent airway infectious diseases such as URTI before 1 year of age. Further research is warranted to elucidate the relationship between CL/P and general medical conditions.

Background: Mammographic density (MD) is a well-established risk factor for breast cancer. Air pollution is a major public health concern and a recognized carcinogen. We aim to investigate the association between MD and exposure to specific air pollutants (SO₂, CO, NO, NO₂, NO_x, PM_2.5, PM₁₀, and O₃) in premenopausal females.

Methods: This cross-sectional study, carried out in Spain, included 769 participants who attended their gynecological examinations. Hourly concentrations of the pollutants were extracted from the Air Quality Monitoring System of Madrid City over a 3-year period. Individual long-term exposure to pollutants was assessed by geocoding residential addresses and monitoring stations, and applying ordinary kriging to the 3-year annual mean concentrations of each pollutant to interpolate the surface of Madrid. This exposure variable was categorized into quartiles. In a first analysis, we used multiple linear regression models with the log-transformed percent MD as a continuous variable. In a second analysis, we used MD as a dichotomous variable (“high” density (MD > 50%) vs. “low” density (MD ≤ 50%)) and applied multiple logistic regression models to estimate odds ratios (ORs). We also analyzed the correlation among the pollutants, and performed a principal component analysis (PCA) to reduce the dimensionality of this set of eight correlated pollutants into a smaller set of uncorrelated variables (principal components (PCs)). Finally, the initial analyses were applied to the PCs to detect underlying patterns of emission sources.

Results: The first analysis detected no association between MD and exposure to any of the pollutants. The second analysis showed non-statistically significant increased risks (OR_Q4; IC95%) of high MD were detected in women with higher exposure to SO₂ (1.50; 0.90–2.48), and PM_2.5 (1.27; 0.77–2.10). In contrast, non-significant ORs < 1 were found in all exposure quartiles for NO (OR_Q2 = 0.72, OR_Q3 = 0.68, OR_Q4 = 0.78), and PM₁₀ (OR_Q2 = 0.69, OR_Q3 = 0.82, OR_Q4 = 0.72). PCA identified two PCs (PC1: “traffic pollution” and PC2: “natural pollution”), and no association was detected between MD and proximity to these two PCs.

Conclusions: In general, our results show a lack of association between residential exposure to specific air pollutants and MD in premenopausal females. Future research is needed to confirm or refute these findings.

Background: Substance abuse is a global problem that cuts across all sectors of society and requires innovative solutions that go beyond conventional treatments. Contact with nature could be a complementary tool to address drug-related problems. This review aimed to assess the impact of natural environments on drug-related outcomes.

Method: 8205 articles were screened between 2013 and 2023 from 6 databases, of which 21 met the inclusion criteria.

Results: Most studies (12) focused on treatment, followed by incidence/consumption (7), prevention (5) and mortality (1). The main drugs studied were drugs in general (12), followed by alcohol (6), tobacco (6), and other drugs, including cannabis and opioids (4). The results of 85% of the studies showed positive outcomes, supporting the effectiveness of nature-based interventions for drug dependence. While some studies produced neutral or negative results.

Conclusion: The use of nature-based interventions for the prevention and treatment of drug addiction shows considerable potential. However, more research is needed to understand the underlying mechanisms and to improve evidence-based interventions. Integrating health and environmental policies is essential to promote a holistic approach to drug strategies at the national and international levels.

Background: Organophosphate flame retardants (OPFRs) are commonly used in various consumer products to prevent fire hazards. However, OPFRs have been linked to several health problems, including cancer. This study aimed to investigate the association between urine levels of OPFRs and endometrial cancer (EC), and to explore the correlation between concentrations of parent OPFR compounds and their metabolites.

Methods: Urine samples from 76 EC patients and 76 healthy controls were collected and analyzed for the levels of five common parent OPFRs and their respective metabolites. Propensity score matching was applied to account for differences in baseline characteristics between the two participant groups. Significantly higher levels of OPFRs in EC patients were identified, and logistic regression models were used to determine whether elevated OPFRs were associated with EC and to explore whether any lifestyle behaviors contributed to the increased OPFR levels. Spearman’s rank correlation coefficients between the concentrations of the parent compounds and their metabolites were calculated.

Results: Out of the ten OPFRs studied, the median urine levels of bis(1,3-dichloro-2-propyl) phosphate (BDCPP), tris(2-butoxyethyl) phosphate (TBEP), and di-(2-butoxyethyl) phosphate (DBEP) were significantly higher in EC patients compared to healthy controls. After matching 41 patients with 41 controls, multiple logistic regression analysis revealed that only BDCPP (OR 4.274; 95% CI 1.172–15.592) was an independent factor associated with EC. A lifestyle questionnaire survey found that urine BDCPP levels were related to age (OR 4.294; 95% CI 1.015–18.164), meals eaten out (OR 4.238; 95% CI 1.454–12.354), and consumption of chilled-ready meals (OR 0.118; 95% CI 0.014–0.985). A positive correlation was only observed between the concentrations of TBEP and its metabolite DBEP; other correlations were not significant.

Conclusion: We concluded that higher urine BDCPP level was an independent factor associated with EC, and higher BDCPP levels were related to aging, more meals eaten out, and fewer chilled-ready meals. These findings highlight the potential hazard of long-term OPFR exposure on the development of EC.

Background: Dehydration, a risk factor for ischemic cerebrovascular diseases, is common in summer; however, the incidence of ischemic diseases is not necessarily higher in summer. Therefore, this study aimed to clarify the relationships between serum osmolarity, hematocrit, daily non-alcohol drink (NAD) intake and factors such as season and age as risk factors for dehydration.

Method: Participants (703 women and 306 men) in the follow-up survey, in 2012 and 2013, of the Kobe Orthopedic and Biomedical Epidemiologic (KOBE) Study, consisting of healthy individuals living in Kobe, Japan, were categorized into two groups based on the examination month: the warmer and colder seasons. Multivariate analyses were conducted to examine disparities in serum osmolarity, hematocrit, and NAD intake between these two groups.

Results: The colder season was found to be negatively correlated with serum osmolarity and NAD intake, but positively correlated with hematocrit, even after adjusting for relevant factors. Age was independently associated with serum osmolarity, but not with hematocrit and NAD intake.

Conclusions: This study suggests that intra-vascular volume depletion is more likely in the colder season despite lower serum osmolarity compared to the warmer season. Age-related increases in serum osmolarity without a corresponding rise in water intake may contribute to this. These findings support the importance of addressing dehydration in the colder season, particularly in older adults.

Background: The association between alcohol consumption and atherosclerotic cardiovascular disease (ASCVD) was controversial, and no previous studies have shown the impact of dyslipidemia on the association. We aimed to clarify the association between alcohol consumption and death from cardiovascular disease (CVD) and its subtypes and the impact of dyslipidemia on the association.

Methods: We conducted a 20-year cohort study to clarify the association between alcohol intake and death from CVD and its subtypes in 2,909 Japanese men. We estimated the hazard ratio (HR) and 95% confidence intervals (CIs) for current drinkers with non-drinkers as the reference, after adjusting for potential confounders using Cox proportional hazards models. We also investigated the association between alcohol consumption and ASCVD or CVD death stratified by the presence or absence of dyslipidemia.

Results: During 50,782 person-years of follow-up period, 223 participants died from total CVD, 110 participants died from ASCVD, and 25 participants died from cerebral hemorrhage. Current drinkers with 1 gou/day were significantly associated with lower risk of ASCVD (HR: 0.60, 95%CI: 0.37–0.98), which is more apparent in those without dyslipidemia, and current drinkers with ≥3 gou/day were significantly associated with higher risk of cerebral hemorrhage (HR: 4.13, 95%CI: 1.12–15.19).

Conclusions: Small amounts of alcohol drinking were associated with lower risk of ASCVD in Japanese men, especially those without dyslipidemia. Meanwhile, excessive alcohol drinking was associated with higher risk of cerebral hemorrhage. Our findings suggest that it is important for current Japanese drinkers to reduce alcohol consumption for preventing ASCVD or cerebral hemorrhage.

Background: Mask use is a critical precaution to prevent the transmission of SARS-CoV-2 in a crowded or densely populated indoor environment. There is still a lack of large-sample studies on mask use in children during the COVID-19 pandemic.

Methods: A questionnaire was distributed to individuals under 18 years of age from the pediatric outpatient department from November 2021 to May 2022. Participants who were willing to be interviewed and had good communication and judgment skills participated in our study.

Results: 5053 (a boy-to-girl ratio of 1.13:1 and a median age of 5 years) from 6200 individuals admitted to the pediatric outpatient department were enrolled in the study. The mask-wearing time increased in parallel with age. Children aged 3–5 years wore masks more correctly (χ² = 41.591, P < 0.05), complained more about the discomfort (χ² = 193.871, P < 0.05), and their parents/caregivers were significantly better aware of the preventive effect of masks on respiratory disease (χ² = 19.501, P < 0.05) than parents/caregivers of other age groups. Masks designed for children were more used by those aged 3–5 years in outdoor settings. The commonest adverse events of mask-wearing were respiratory symptoms (61.2%), followed by dermatological symptoms (28.9%) and psychological symptoms (19.7%). Girls wore masks for a longer time and more correctly (χ² = 10.598, P < 0.05) than boys. Compared with the pre-COVID-19 pandemic, wearing masks could significantly decrease the median frequency of respiratory infections during the COVID-19 pandemic (2[1–4] vs 3[2–4]; z = −2.692, P < 0.05).

Conclusions: Wearing proper and well-fitted masks could significantly protect children from respiratory infections in a crowded or densely populated indoor environment during the COVID-19 pandemic. However, mask-associated adverse events, particularly in psychological symptoms, are needed to draw adequate attention, calling for early identifications and psychological interventions.

Background: Long-term exposure to inorganic arsenic (InAs) through arsenic (As)-contaminated drinking water poses serious health risks. However, epidemiological studies focusing on low-level dietary exposure to InAs are lacking. Furthermore, although toenail clippings are used as biomarkers for assessing As exposure in areas with contaminated drinking water, to date, no method has been developed for using toenails as a biomarker of long-term InAs exposure in individuals with lower exposure levels, e.g., from dietary sources including fish and seaweeds. Therefore, this study aimed to assess the feasibility of using toenails as biomarkers for estimating InAs exposure in Japanese adults.

Methods: Three sets of 7-day diet records and toenail clipping samples were collected from 39 healthy adult participants at intervals of 1–6 months over 4–8 months, spanning from June 2019 to March 2020. The analysis sample sets comprised 113 sample sets obtained from 38 subjects: 56 samples from 19 males and 57 samples from 19 females. The speciation of As species in the toenail samples was performed using high-performance liquid chromatography-inductively coupled plasma mass spectrometry. The sum of the InAs and monomethylarsonic acid (MMA) or sum of As species (sum-As) concentrations in toenail samples was used as an index of InAs exposure.

Results: The geometric mean (GM) concentration of InAs + MMA or sum-As in toenails was 0.180 µg As/g or 0.284 µg As/g. The estimated GM of daily dietary InAs exposure was 0.147 µg/kg/day. Log-transformed InAs + MMA or sum-As concentrations in toenails did not predict dietary InAs exposure levels from rice and hijiki consumption in both males and females. Similarly, toenail InAs + MMA or sum-As concentrations showed no correlation with dietary InAs exposure levels from rice or hijiki consumption.

Conclusions: Our findings indicate that human toenail clippings are not a suitable biomarker for assessing long-term InAs exposure levels in Japanese individuals based on the observed range of InAs and its metabolite concentrations in toenails.

Background: Dioxin is an environmental pollutant as well as an endocrine disruptor in humans. Our longitudinal study wants to clarify the relationship between dioxin exposure and endocrine disorders in children living in the Vietnamese dioxin hotspot.

Method: Seventeen congeners of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzo-furans (PCDDs/PCDFs) in maternal breast milk and seven serum steroid hormones in children of 43 and 46 mothers and their 9-year-old children from the non-exposure and the hotspot areas were measured, respectively. The steroid metabolic enzyme ratios were calculated based on the hormone level ratio.

Results: Most dioxin/furan congeners and toxic equivalents (TEQs) levels were significantly higher in the hotspot than in the non-exposure area, except for 2,4,7,8-TeCDF. The height and weight of girls from the hotspot area were substantially lower and inversely correlated with dioxin congener levels/total TEQs level dioxin. The dihydrotestosterone (DHT) levels in the hotspot were markedly lower than those in non-exposed in both genders. The cortisol concentrations were significantly higher in the hotspot than those from the non-exposure area only in the girls. The DHT/testosterone ratios that exhibited the 5α- or 5β-reductase activity declined by 50% in the hotspot area for both genders. The DHT levels showed strong inverse correlations with almost the PCDDs/PCDFs congeners and total TEQs dioxin in breast milk.

Conclusions: This finding suggests that dioxin exposure in maternal breast milk might impact children’s endocrine system until 9 years old, especially on the DHT biosynthesis.

Background: The acute effects of temperature and air pollution on mortality are well-known environmental factors that have been receiving more recognition lately. However, the health effects resulting from the interaction of air pollution and temperature remain uncertain, particularly in cities with low levels of pollution. This study aims to examine the modification effects of particulate matter with a diameter of 2.5 µm or less (PM_2.5) and ozone (O₃) on the association between temperature and mortality.

Methods: We collected the daily number of all-cause, cardiovascular, and respiratory mortality from 20 major cities in Japan from 2012–2018. We obtained meteorological data from the Japan Meteorological Agency and air pollution data from the National Institute for Environmental Studies. We conducted analyses using a quasi-Poisson regression model with a distributed lag non-linear model for temperature in each city and subsequently performed a random-effects meta-analysis to derive average estimates.

Results: We found that high levels of O₃ might positively modify the mortality risk of heat exposure, especially for cardiovascular diseases. Subgroups such as the elderly and females were susceptible. We did not observe consistent evidence of effect modification by PM_2.5, including effect modification on cold by both pollutants.

Conclusion: PM_2.5 and O₃ may positively modify the short-term association between heat and mortality in the urban areas of Japan. These results highlight the need for public health policies and interventions to address the collective impacts of both temperature and air pollution.

Background: The projection indicates that compound drought and hot events (CDHEs) will intensify, posing risks to cardiovascular health by potentially increasing stroke incidents. However, epidemiological evidence on this topic remains scarce. This study investigates the association between exposure to CDHEs and the risk of daily stroke admissions, specifically examining the effects on various stroke categories such as Subarachnoid Hemorrhage (SAH), Intracerebral Hemorrhage (ICH), Ischemic Stroke (IS), Transient Ischemic Attack (TIA), and other types of stroke.

Methods: Data on daily stroke admissions from 2010 to 2015 were obtained from the Urban Employee Basic Medical Insurance (UEBMI) and Urban Resident Basic Medical Insurance (URBMI) claims databases in Guangzhou, China. Hot events were identified as days when the daily mean temperature exceeded the 75th percentile during the warm season (May to October) over the study period. The Standardized Precipitation Evapotranspiration Index (SPEI) was utilized to identify drought conditions, with thresholds set at −1 and −1.5 for low-severity and high-severity drought events, respectively. Through a generalized additive model (GAM), we analyzed the cumulative effects of CDHE exposure on daily stroke admissions and calculated the Attributable Fraction (AF) related to CDHEs.

Results: The analysis included 179,963 stroke admission records. We observed a significant increase in stroke admission risks due to exposure to hot events coupled with high-severity drought conditions (RR = 1.18, 95%CI: 1.01–1.38), with IS being the most affected category (RR = 1.20, 95%CI: 1.03–1.40). The AF of total stroke admission attributed to hot events in conjunction with high-severity drought conditions was 24.40% (95%CI: 1.86%–50.20%).

Conclusion: The combination of hot events with high-severity drought conditions is likely linked to an increased risk of stroke and IS admissions, which providing new insights into the impact of temperature and climate-related hazards on cardiovascular health.

Background: The East Asian-specific genetic diversity, the rs671 variant of aldehyde dehydrogenase 2, causes the “Asian flush” phenomenon following alcohol consumption, resulting in an alcohol avoidance phenotype. The variant is suggested as a risk factor for Alzheimer’s disease; however, its association with mild cognitive impairment (MCI), an effective target for secondary prevention of dementia, remains unclear.

Method: This cross-sectional study examined 430 individuals aged 60–80 years (251 women) without overt cognitive impairment in Yoshinogari, Japan. The effect of the rs671 variant on MCI, defined by scores <26 or <25 on the Japanese version of the Montreal Cognitive Assessment, was evaluated using multivariate logistic regression.

Results: The models included APOEε4, sex, age, education, history of habitual drinking, Brinkman index, hypertension, diabetes, and subclinical magnetic resonance imaging findings and consistently estimated the risk of the rs671 variant. Subsequently, stratified analyses by history of habitual drinking were performed based on an interactive effect between rs671 and alcohol consumption, and the rs671 variant significantly influenced MCI in participants who did not drink habitually, with odds ratios ranging from 1.9 to 2.1 before and after adjusting for covariates, suggesting an association independent of hippocampal atrophy and small vessel dysfunction. Conversely, no such association with the rs671 variant was observed in participants with a history of habitual alcohol use. Instead, hippocampal atrophy and silent infarcts were associated with MCI.

Conclusions: This is the first study to demonstrate an association between the rs671 variant and MCI morbidity. The findings highlight the need for race-specific preventive strategies and suggest potential unrecognized mechanisms in dementia development.

Background: The purpose of this study was to investigate the impact of single nucleotide polymorphisms (SNPs) of the CYP1A1 gene and the gene-environment interaction on the susceptibility to endometrial cancer in Chinese women.

Method: Logistic regression was performed to investigate the association between the four SNPs of the CYP1A1 gene and the risk of endometrial cancer. Generalized multifactor dimensionality reduction (GMDR) was employed to analyze the gene-environmental interaction.

Results: A total of 934 women with a mean age of 61.7 ± 10.5 years were selected, including 310 endometrial cancer patients and 624 normal controls. The frequency of rs4646421- T allele was higher in endometrial cancer patients than normal controls, the T allele of rs4646421 was 28.1% in endometrial cancer patients and 21.0% in normal controls (p < 0.001). Logistic regression analysis showed that the rs4646421 - T allele was associated with increased risk of endometrial cancer, OR (95% CI) were 1.52 (1.11–1.97) and 1.91 (1.35–2.52), respectively. GMDR analysis found a significant two-locus model (p = 0.0107) involving rs4646421 and abdominal obesity (defined by waist circumference), indicating a potential gene–environment interaction between rs4646421 and abdominal obesity. Abdominal obese subjects with rs4646421- CT or TT genotype have the highest risk of endometrial cancer, compared to non-abdominal obese subjects with the rs4646421- CC genotype, the OR (95%CI) was 2.23 (1.62–2.91).

Conclusions: Both the rs4646421- T allele and the interaction between rs4646421 and abdominal obesity were associated with increased risk of endometrial cancer.

Background: In a study conducted in Kochi Prefecture, Shikoku, Japan, during the early stages of the pandemic in spring 2020, we found that emergency transportations due to acute alcohol intoxication decreased. We aimed to determine how the decline in the number of emergency transportations due to acute alcohol intoxication changed during the four years following the COVID-19 pandemic’s onset.

Methods: This study used data of 107,013 emergency transportations from the Kochi-Iryo-Net database, Kochi Prefecture’s emergency medical and wide-area disaster information system. We categorized emergency transportation cases according to the diagnoses entered into the system by the attending physician, which were then divided into alcohol- and non-alcohol-related intoxication cases based on the diagnostic codes in the International Classification of Diseases Manual, 10th edition, Clinical Modification. We performed chi-square tests and multiple logistic regression to examine the association between emergency transportations and acute alcohol intoxication.

Results: The number of emergency transportations due to acute alcohol intoxication was 412 (1.8%) in 2019, and it declined to 268 (1.4%), 248 (1.2%), 270 (1.2%), and 283 (1.3%) in 2020, 2021, 2022, and 2023, respectively. After adjusting for confounding factors such as fire department and age, a significant decrease was observed in the subsequent years compared with 2019 (2020: adjusted odds ratio, 0.79; 95% confidence interval, 0.68–0.93; 2021: adjusted odds ratio, 0.74; 95% confidence interval, 0.63–0.87; 2022: adjusted odds ratio, 0.73; 95% confidence interval, 0.62–0.85; 2023: adjusted odds ratio, 0.76; 95% confidence interval, 0.65–0.89).

Conclusions: This study examined changes in emergency transportation due to acute alcohol intoxication during and after the COVID-19 pandemic, especially when social events and other activities returned to “normal.” Compared with 2021, which was when emergency transportations due to acute alcohol intoxication were at their lowest, a slight increase was observed in the number of transportations in subsequent years.

Background: An increased risk of diabetes after COVID-19 exposure has been reported in Caucasians during the early phase of the pandemic, but the effects across viral variants and in non-Caucasians have not been evaluated.

Methods: To address this gap, survival analyses were performed for five outbreak periods. From an anonymized health insurance database REZULT for the employees and their dependents of large companies or government agencies in Japan, 5 matched cohorts were generated based on age, sex, area of residence (47 prefectures), and 7 ranges of medical bills (COVID-19 exposed:unexposed = 1:4). Observation of each matching group began on the same day. Incident diabetes type 1 (T1D) and type 2 (T2D) were defined as the first claim during the target period, including at least 1 year before the start of observation.

Results: T1D accounted for 0.8% of incident diabetes after the first COVID-19 exposure, similar to the non-exposed cohort. Most T2D in the COVID-19 cohort was observed within a few weeks. After further adjustment for the number of days from the start of observation to hospitalization (a time-dependent variable), the hazard ratio for incident T2D ranged from 14.1 to 20.0, with 95% confidence intervals (95%CI) of 8.7 to 32.0, during the 2-month follow-ups from the original strain outbreak to the Delta variant outbreak (by September 2021), and decreased to 2.0, with a 95%CI of 1.6 to 2.5, during the Omicron outbreak (by March 2022). No association was found during the BA.4/5 outbreak (until September 2022). Males had a higher risk, and the trend toward higher risk in older age groups was inconsistent across the periods.

Conclusions: Our large dataset, covering 2019–2023, reports for the first time the impact of COVID-19 on incident diabetes in non-Caucasians. The risk intensity and attributes of post-COVID-19 T2D were inconsistent across outbreak periods, suggesting diverse biological effects of different SARS-CoV-2 variants.

Background: Per- and poly-fluoroalkyl substances (PFASs) are pervasive synthetic compounds, prompting investigations into their intricate interactions with lifestyle factors and health indicators because of their enduring environmental presence and bioaccumulation. This study aimed to explore the effects of the oxidative balance score (OBS) and PFAS on liver-related indices.

Methods: Twenty dietary and lifestyle factors were used to calculate the OBS. The serum concentrations of PFASs were measured, and their sum was calculated for analysis. The levels of liver markers were also evaluated. Linear regression models and interaction analyses were used to assess the associations between OBS, PFAS concentrations, and liver indices.

Results: The results revealed an inverse association between high OBS and perfluorooctane sulfonic acid concentration, as well as the sum of PFAS concentrations. OBS was positively associated with liver markers. The PFAS concentrations were positively associated with total bilirubin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels. Interaction analyses revealed significant interactions between OBS and specific PFASs for alkaline phosphatase (interaction P < 0.05). Possible interactions were also found between OBS and specific PFASs for ALT, and AST levels (interaction P < 0.10).

Conclusions: This study clarified the association between total PFAS and OBS. This association was significant mainly for diet-related OBS. PFAS and OBS are associated with liver-related indicators in the blood.

Background: Chronic noise exposure poses a remarkable public health concern, drawing attention to its impacts on the brain. Ferroptosis is involved in several brain-related diseases. However, the role of ferroptosis in the effects of chronic noise on the brain remains elusive. This study aimed to investigate the effects of chronic noise exposure on the brain and elucidate the underlying mechanisms.

Methods: A chronic noise-induced cognitive impairment model in rats was constructed and validated. The pathological state and ferroptosis level of the rat hippocampus were determined using Western blotting and immunohistochemistry. Bioinformatics was employed to investigate the interrelationship between chronic noise exposure and genes. Genetic relationships were analyzed using Mendelian randomization (MR) analysis. Cytoscape was employed for the prediction of upstream molecular and drug targets.

Results: In vivo experiments revealed that chronic noise exposure could induce Alzheimer’s disease (AD)-like neuropathological changes in rat hippocampus and cognitive impairment. Moreover, protein markers indicative of ferroptosis and levels of lipid peroxidation were quantified to elucidate underlying mechanisms. Thereafter, oxidative stress- and ferroptosis-related differentially expressed genes (DEGs) underwent functional enrichment and PPI network analyses. Additionally, 8 genes with diagnostic significance were identified. In MR analysis, retinoic acid receptor responder 2 (Rarres2) gene exhibited a negative genetic relationship with AD.

Conclusions: Chronic noise exposure could induce AD-like neuropathological changes and cognitive impairment via ferroptosis. The results of MR analysis indicated that Rarres2 gene may act as a protective factor in AD. This gene may be upstream of ferroptosis and serve as a target for the prevention and treatment of chronic noise-induced cognitive impairment.

Background: A growing body of evidence has documented unfavorable maternal outcomes attributed to excessive antenatal coffee consumption. Preeclampsia is one of the most common hypertensive disorders of pregnancy with several adverse maternal and neonatal outcomes. However, the association between antenatal coffee consumption and preeclampsia remains debatable. Herein, we performed a systematic review and meta-analysis of available evidence to investigate this association.

Methods: After systematically reviewing PubMed and Scopus for eligible studies published until October 2023, we pooled the odds ratios (ORs) and their 95% confidence intervals (CIs) of preeclampsia for women who reported the highest versus the lowest frequencies of antenatal coffee consumption. We used the I² statistic to measure heterogeneity across studies and the funnel plot asymmetry to assess publication bias.

Results: This meta-analysis included seven retrospective studies (six case-control studies and one cross-sectional study) investigating 904 women with preeclampsia and 6,257 women without it. Combined, the highest frequencies of antenatal coffee consumption were associated with higher odds of preeclampsia: (pooled OR = 1.39, 95% CI: 1.03, 1.86), with a moderate heterogeneity across studies (I² = 40.34% and p-value for heterogeneity = 0.122) and no publication bias (z = 0.610 and p-value for publication bias = 0.542). However, excluding the cross-sectional study, which contributed to 24.3% of the meta-analysis weight, left the association statistically non-significant: (pooled OR = 1.33, 95% CI: 0.91, 1.95; I² = 44.59%). The association became even weaker after limiting the analysis to studies that excluded women with chronic hypertension: (pooled OR = 1.21, 95% CI: 0.77, 1.89; I² = 41.64%) or after excluding studies with low quality: (pooled OR = 1.24, 95% CI: 0.70, 2.19; I² = 65.79%).

Conclusion: The association between antenatal coffee consumption and preeclampsia remains inconclusive. Future prospective cohort studies are needed to better investigate this association.

Background: This study explored the association between working hours and preventive oral health behaviors.

Methods: In total, 48,599 workers (22,992 females) were included from the Korea National Health and Nutrition Examination Survey (2007–2021). Weekly working hours were self-reported. The following three preventive oral health behaviors were set as outcomes: participation in annual dental check-ups; adherence to the recommended toothbrushing frequency (≥twice a day); and use of interdental cleaning devices. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression.

Results: In male workers, the adjusted OR (95% CI) of the association between working ≥55 h/week and each outcome was 0.84 (0.77–0.92) for dental check-ups, 0.82 (0.72–0.94) for toothbrushing ≥twice a day, and 0.83 (0.76–0.92) for utilization of interdental cleaning device when compared to 35–40 h/week. In female workers, the adjusted OR (95% CI) of the association between working ≥55 h/week and each outcome was 0.79 (0.70–0.89) for dental check-ups, 0.88 (0.70–1.11) for toothbrushing ≥twice a day, and 0.80 (0.71–0.90) for utilization of interdental cleaning device when compared to 35–40 h/week. Additionally, low socio-economic status, such as low educational attainment, low income level, and blue-collar occupations, were major risk factors associated with non-adherence to preventive oral health behaviors in both male and female workers.

Conclusions: Our study suggests that individuals who work long hours are more likely to exhibit undesirable oral health behaviors.

Background: High blood pressure (HBP) and diabetes mellitus (DM) are two of the most prevalent cardiometabolic disorders globally, especially among individuals with lower socio-economic status (SES). Studies have linked residential greenness to decreased risks of HBP and DM. However, there has been limited evidence on whether SES may modify the associations of residential greenness with HBP and DM.

Methods: Based on a national representative cross-sectional study among 44,876 adults, we generated the normalized difference vegetation index (NDVI) at 1 km spatial resolution to characterize individuals’ residential greenness level. Administrative classification (urban/rural), nighttime light index (NLI), individual income, and educational levels were used to characterize regional urbanicity and individual SES levels.

Results: We observed weaker inverse associations of NDVI with HBP and DM in rural regions compared to urban regions. For instance, along with per interquartile range (IQR, 0.26) increment in residential NDVI at 0∼5 year moving averages, the ORs of HBP were 1.04 (95%CI: 0.94, 1.15) in rural regions and 0.85 (95%CI: 0.79, 0.93) in urban regions (P = 0.003). Along with the decrease in NLI levels, there were continuously decreasing inverse associations of NDVI with DM prevalence (P for interaction <0.001). In addition, weaker inverse associations of residential NDVI with HBP and DM prevalence were found among individuals with lower income and lower education levels compared to their counterparts.

Conclusions: Lower regional urbanicity and individual SES could attenuate the associations of residential greenness with odds of HBP and DM prevalence.

Background: Atrazine (ATR), a commonly used herbicide, is linked to dopaminergic neurotoxicity, which may cause symptoms resembling Parkinson’s disease (PD). This study aims to reveal the molecular regulatory networks responsible for ATR exposure and its effects on dopaminergic neurotoxicity based on an integration strategy.

Methods: Our approach involved network toxicology, construction of protein-protein interaction (PPI) networks, gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, as well as molecular docking techniques. Subsequently, we validated the predicted results in PC12 cells in vitro.

Results: An integrated analysis strategy indicating that 5 hub targets, including mitogen-activated protein kinase 3 (Mapk3), catalase (Cat), heme oxygenase 1 (Hmox1), tumor protein p53 (Tp53), and prostaglandin-endoperoxide synthase 2 (Ptgs2), may play a crucial role in ATR-induced dopaminergic injury. Molecular docking indicated that the 5 hub targets exhibited certain binding activity with ATR. Cell counting kit-8 (CCK8) results illustrated a dose-response relationship in PC12 cells. Real-time quantitative polymerase chain reaction (RT-qPCR) displayed notable changes in the expression of hub targets mRNA levels, with the exception of Mapk3. Western blotting results suggested that ATR treatment in PC12 cells resulted in an upregulation of the Cat, Hmox1, and p-Mapk3 protein expression levels while causing a downregulation in Tp53, Ptgs2, and Mapk3.

Conclusion: Our findings indicated that 5 hub targets identified could play a vital role in ATR-induced dopaminergic neurotoxicity in PC12 cells. These results provide preliminary support for further investigation into the molecular mechanism of ATR-induced toxicity.

One consequence of population aging is an increase in the number of older wheelchair users. They often board the motor vehicle from the rear for moving. Recently, wheelchair user vehicle passengers have involved in motor vehicle collisions and died. A three-point seatbelt does not adequately fit most wheelchair user passengers because of the way that the wheelchair is constructed. Therefore, owing to the movement of the body immediately after the collision, the wheelchair user passengers attacked their body to the interior of the vehicle or suffered from the intrusion of the lap belt into the abdomen, subsequently suffered from severe head, chest or abdominal injuries. According to the review of all fatal motor vehicle collisions in Shiga Prefecture, Japan, which has a population of approximately 1.4 million, from 2017 to 2022, the rate of wheelchair users in fatal motor vehicle passenger increased from 3.6% in 2017 to 2019 to 7.8% in 2020 to 2022. Therefore, there is a risk that substantial numbers of wheelchair user passengers involved in motor vehicle collisions will die. However, in Japan, there are no official statistics on the involvement of wheelchair user passengers in motor vehicle collisions. Therefore, we propose a nationwide registration of injuries and fatalities in wheelchair user passengers. Investigating the mechanisms of injury in wheelchair user passengers would contribute to the development of safety measures, especially for restraint systems. Established preventive measure would contribute to the decrease of fatally or severely injured motor vehicle collision passengers.

Background: This study examined the association between neurological symptoms and quality of life (QoL) in patients with neurofibromatosis type 2 (NF2) using a national database of all patients who newly claimed for medical expense subsidies in Japan from 2015 to 2019.

Methods: The Japanese Ministry of Health, Labour and Welfare provided access to the “National Database of Designated Intractable Diseases of Japan” containing the “Medical Certificates of Designated Intractable Diseases” of all patients with NF2. The database included information on five items of QoL: “mobility,” “self-care,” “usual activities,” “pain/discomfort,” and “anxiety/depression.” To examine the association between the presence/absence of neurological symptoms and QoL, multivariable logistic regression analyses were performed, adjusted for potential confounders.

Results: Data from 187 patients (97 females and 90 males; mean (standard deviation) age, 43.1 (17.9) years) were analyzed. Overall, 31% to 55% of patients were recorded as having moderate/severe impairment of QoL. Spinal dysfunction was significantly associated with deterioration of all components of QoL, whereas speech dysfunction and hemiparesis were specifically associated with physical health-related components of QoL. Spinal dysfunction, facial nerve palsy, and age 25–64 years were significantly associated with “anxiety/depression.”

Conclusions: In the present epidemiological study using a national database of NF2 in Japan, spinal dysfunction was significantly associated with deterioration of all components of QoL, including subjective and mental health-related components of QoL, whereas speech dysfunction and hemiparesis were specifically associated with physical health-related components of QoL.

Background: Plastic additives have adverse effects on human health. Children frequently use toys that contain various substances found in paints, plasticizers, and other materials, which heighten the risk of specific chemical exposure. Infants are particularly prone to chemical exposure through the “mouthing” behavior because of the possibility of placing toys in their mouths. Thus, this vulnerability should be considered during risk assessments of chemical exposure.

Methods: This study performed a comprehensive analysis of the chemical components in various 84 plastic toys including “designated toys” (toys that may be harmful to infant health if in contact with their mouths: Article 78 of the Enforcement Regulations of the Food Sanitation Law by the Minister of Health, Labor and Welfare) such as dolls, balls, blocks, bathing toys, toy vehicles, pacifiers, and household items, purchased in the Japanese market by nontargeted and targeted analysis.

Results: Plasticizers, flame retardants, and fragrances were the main compounds in almost all the toy products. The results showed that plastic products made in China tended to contain high levels of phthalate esters. In particular, hazardous plasticizers, such as diisodecyl, di-n-octyl, and diisononyl phthalates were detected above the regulatory limit (0.1%) in used products manufactured before regulations were passed in Japan. Furthermore, we detected alternative plasticizers, such as acetyl tributyl citrate (ATBC; 52%), diisononyl adipate (DINA; 50%), and di(2-ethylhexyl) terephthalate (DEHT; 40%). ATBC was detected at high concentrations in numerous toy products. Thus, infants with free access to indoor plastic toys might be exposed to these chemicals.

Conclusions: This study observed that the chemical profiles of toy products were dependent on the year of manufacture. Furthermore, the detection of currently regulated plasticizers in secondhand products manufactured before regulations were enforced, along with the increasing trend of using alternative substances to regulated phthalate esters in products, suggests the potential exposure of infants to these plasticizers through the use of toys. Therefore, regular fact-finding surveys should continue to be conducted for the risk assessment and safety management of domestic toy products.

Background: Poor oral hygiene, generally manifesting as dental caries, gingivitis, or periodontitis, is a common chronic condition among both children and adults worldwide and has been reportedly associated with hypertension and arterial stiffness mainly in adult patients. However, these associations have not been well-studied in children and adults in the general population. Therefore, we conducted this cross-sectional study to clarify the associations between oral hygiene indices and high blood pressure (BP)/hypertension and arterial stiffness as assessed by the cardio-ankle vascular index (CAVI) in children along with their mothers. The association between maternal oral hygiene and high BP in children was also examined based on the hypothesis that maternal awareness of oral hygiene is related to their children’s oral hygiene.

Methods: This study was conducted as an Adjunct Study of the Aichi Regional Sub-Cohort of the Japan Environment and Children’s Study. Participating children (n = 220, 85–104 months old) and their mothers (n = 217, 29–52 years old) underwent dental/intra-oral examination and BP and CAVI assessment. High BP in children and hypertension in mothers were diagnosed according to corresponding American guidelines. Logistic regression analysis or analysis of covariance was used to examine the associations of poor oral hygiene indices with BP and CAVI.

Results: Maternal dental caries ≥1 was associated with their hypertension (adjusted odds ratio [aOR]: 2.72, 95% confidence interval (CI): 1.12–6.61). Maternal dental plaque ≥1/3 was associated with maternal hypertension and children’s high BP (aOR, 95% CI: 4.71, 1.33–16.73 and 5.67, 1.22–25.04, respectively). Maximum pocket depth ≥4 mm was associated with children’s high BP (aOR: 6.85, 95% CI: 1.24–38.01). No associations were observed between oral hygiene indices and CAVI in children; however, there was a significant association between dental plaque and CAVI in mothers (F = 5.62, p < 0.01).

Conclusions: The small sample size, especially the case number, made it necessary to refrain from drawing unambiguous conclusion. The hypothesis that warrants further investigation based on the present study results is that poor oral hygiene is associated with high BP in children and hypertension and arterial stiffness in mothers, and maternal oral hygiene is associated with high BP in children.

Background: Arsenic is a toxic metalloid that can cause acute and chronic adverse health problems. Unfortunately, rice, the primary staple food for more than half of the world’s population, is generally regarded as a typical arsenic-accumulating crop plant. Evidence indicates that arsenic stress can influence the growth and development of the rice plant, and lead to high concentrations of arsenic in rice grain. But the underlying mechanisms remain unclear.

Methods: In the present research, the possible molecules and pathways involved in rice roots in response to arsenic stress were explored using bioinformatics methods. Datasets that involving arsenic-treated rice root and the “study type” that was restricted to “Expression profiling by array” were selected and downloaded from Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between the arsenic-treated group and the control group were obtained using the online web tool GEO2R. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed to investigate the functions of DEGs. The protein-protein interactions (PPI) network and the molecular complex detection algorithm (MCODE) of DEGs were analyzed using STRING and Cystoscope, respectively. Important nodes and hub genes in the PPI network were predicted and explored using the Cytoscape-cytoHubba plug-in.

Results: Two datasets, GSE25206 and GSE71492, were downloaded from Gene Expression Omnibus (GEO) database. Eighty common DEGs from the two datasets, including sixty-three up-regulated and seventeen down-regulated genes, were then selected. After functional enrichment analysis, these common DEGs were enriched mainly in 10 GO items, including glutathione transferase activity, glutathione metabolic process, toxin catabolic process, and 7 KEGG pathways related to metabolism. After PPI network and MCODE analysis, 49 nodes from the DEGs PPI network were identified, filtering two significant modules. Next, the Cytoscape-cytoHubba plug-in was used to predict important nodes and hub genes. Finally, five genes [Os01g0644000, PRDX6 (Os07g0638400), PRX112 (Os07g0677300), ENO1(Os06g0136600), LOGL9 (Os09g0547500)] were verified and could serve as the best candidates associated with rice root in response to arsenic stress.

Conclusions: In summary, we elucidated the potential pathways and genes in rice root in response to arsenic stress through a comprehensive bioinformatics analysis.

Background: Itai-itai disease is the most severe case of chronic cadmium (Cd) toxicity, which was endemic in Cd-polluted areas in the Jinzu River basin in Toyama prefecture, Japan. Akita prefecture also has Cd-polluted areas, but there have been no cases of “itai-itai disease”.

Case presentation: An elderly female farmer with Cd nephropathy residing in a Cd-polluted area in the northern part of the Akita prefecture was identified through hospital-based screening at Akita Rosai Hospital in Odate city. She had chronic renal failure with a high Cd exposure level and advanced renal tubular dysfunction. The shortening of height, bone deformities and fractures, abnormal bone metabolism suggesting osteomalacia, and renal anemia were also noted. Therefore, “itai-itai disease”, similar to cases in the Jinzu River basin, was suspected.

Conclusion: This is the first case of “itai-itai disease” in a Cd-polluted area in Akita prefecture.

Background: In recent years, there has been a diversification of working styles. The concept of workers’ well-being is no longer limited to material wealth, such as how satisfied they are with their wages. Psychological enrichment, encompassing factors like motivation and interpersonal relationships, is also important. This study was established to develop a scale to evaluate the well-being of workers, named the Abundance Index for Workers (AIW). This new concept proposed by the authors comprehensively considers both job-related resources and personal and societal resources.

Methods: This study was carried out as part of the Tsukuba Salutogenic Occupational Cohort Study (T-SOCS). We utilized data from a survey targeting workers affiliated with institutions under the Tsukuba Science City Network, examining aspects of their daily life, work, and mental health. The deviation scores for each survey item were averaged to calculate an overall score. The correlations of the comprehensive score with the Patient Health Questionnaire-9 (PHQ-9) index for depression and the Single-item Presenteeism Question (SPQ) index for presenteeism were analyzed to determine criterion-related validity.

Results: The number of participants analyzed was 2,745. Factor analysis categorized the data into three factors: workplace mental health, societal resources, and lifestyle habits. Cronbach’s α coefficient was 0.688. There were correlations of −0.363 (p < 0.001) between the total score and SPQ, and −0.558 (p < 0.001) between the total score and PHQ-9, suggesting a degree of criterion-related validity.

Conclusions: In this study, we designed a test battery that assesses workers’ well-being based on job-related resources and the richness of societal resources. The internal consistency of this battery was not as high as expected due to the broad scope of well-being. Although it is difficult to evaluate workers’ well-being on a single scale, we believe that the AIW functions well as a test battery by combining scales with different attributes, which enables well-being to be captured from as many different perspectives as possible. This tool is designed to assist individuals in evaluating their own well-being and recognizing factors that can enhance it.

Trial registration: Not applicable; this study is not an intervention trial.

Background: Per- and polyfluoroalkyl substances (PFAS) are now considered global contaminants posing health risks. Recent human biomonitoring data in Japan are presented.

Methods: Human biomonitoring data from Japan, dating back to 2000, were reviewed. In addition, 399 serum samples collected in a primary care clinic in Urayasu City, Okinawa Island—one of the highest PFAS-exposed areas in Japan—between 2021 and 2022 were analyzed. Serum levels of four PFAS were compared with risk levels based on the assessment by Sonne et al. and the European Food Safety Agency.

Results: The PFAS levels in the general population from various areas other than Hokkaido (16.1–43.5 ng/mL) are classified at moderate to severe risk for immunotoxicity based on the assessment.

Conclusions: A portion of the Japanese population has had high exposure to PFAS and was at high risk of immunotoxicity, and this situation remained in PFAS-contaminated areas in the 2020s.

Background: Heavy metals such as lead (Pb) and cadmium (Cd) have been associated with adverse pregnancy and developmental outcomes, including congenital abnormalities. This study investigated the association between exposure to heavy metals and trace elements during fetal life and congenital limb abnormalities in infants.

Methods: This study is based on a prospective ongoing nationwide birth cohort from the Japan Environment and Children’s Study (JECS). The concentrations of Cd, Pb, mercury (Hg), selenium (Se), and manganese (Mn) were measured in maternal blood collected during the mid–late trimesters. Inclusion criteria were available from questionnaires filled in during pregnancy, including information about congenital limb abnormalities at birth or at one month. To examine the associations with limb anomalies and individual chemicals, logistic regression models were applied following log-transformation or division into quartiles of Cd, Pb, Hg, Se, and Mn concentrations. To assess the associations with the heavy metals and trace elements mixture, quantile g-computation was employed. All models were adjusted for age, maternal smoking history, maternal alcohol intake, history of smoking, and infant sex.

Results: Data from 90,163 participants were included in the analysis, of whom 369 had congenital limb abnormalities in any of the collected information, and 89,794 had none. Among the 369 cases of congenital limb abnormalities, there were 185 and 142 cases of polydactyly and syndactyly, respectively. The median concentrations of Pb, Cd, Hg, Se, and Mn were 5.85, 0.66, 3.64, 168, and 15.3 ng/g, respectively. There were no associations between maternal blood concentrations of Pb [adjusted odd ratio = 0.83; 95% confidence interval = 0.61, 1.11], Cd [0.87; 0.68, 1.10], Hg [0.88; 0.73, 1.07], Se [1.07; 0.44, 2.59], and Mn [0.91; 0.64, 1.30] with congenital limb abnormalities. No significant association was observed between the mixture of heavy metals and trace elements [0.85; 0.72, 1.02] and any congenital limb abnormalities. Moreover, there was no association with all polydactylies and all syndactylies, or any type of abnormality as a subdivision.

Conclusion: At the maternal exposure levels of Cd, Pb, Hg, Se, and Mn assessed in the present study, no association was identified with the risk of developing congenital limb abnormalities in children.

Background: Per- and polyfluoroalkyl substances (PFAS) are global contaminants. Seafood consumption is a possible PFAS exposure route to humans while the isomer specific analysis has not been conducted.

Methods: Perfluorooctane sulfonate (PFOS), perfluoroheptane sulfonate (PFHpS) and perfluorohexane sulfonate (PFHxS) were investigated in residents of Kyoto, Japan (n = 51). The relationship between plasma PFAS and seafood consumption biomarker, the ratio of eicosapentaenoic acid to arachidonic acid (EPA/AA) was examined by multiple regression analysis.

Results: Linear PFOS concentrations showed a significant positive correlation with the EPA/AA ratio in plasma samples (β = 6.80, p = 0.0014). Linear PFHpS was marginally associated with EPA/AA ratio (β = 0.178, p = 0.0874). Branched PFOS isomers and PFHxS had no associations with EPA/AA ratios.

Conclusion: Seafood intake may be a significant exposure pathway for PFAS, such as PFOS but the isomers differ.

Background: Exposure to fine particulate matter (PM_2.5) has been associated with allergic diseases, including asthma. However, information about the effects of specific PM_2.5 components is limited. This study aimed to investigate the relationship of exposure to chemical components of PM_2.5 during pregnancy and early childhood with the development of asthma, allergies, and sensitization in school-age children.

Methods: This study included 2,408 children in the second grade of elementary school. Questionnaire surveys of respiratory/allergic symptoms and measurements of serum total IgE and specific IgE levels to house dust mite (HDM) and animal proteins were conducted. Exposures to ambient PM_2.5 mass, sulfate (SO₄²⁻), nitrate (NO₃⁻), ammonium (NH₄⁺), elemental carbon (EC), and organic carbon (OC) of PM_2.5 in participants’ residences from conception to age six were estimated using predictive models. Multiple logistic regression analysis was used to analyze the association of respiratory/allergic symptoms and allergen sensitization with estimated exposure concentrations, after adjustment for survey year, sex, season of birth, feeding method during infancy, presence of siblings, history of lower respiratory tract infection, use of childcare facilities, passive smoking, presence of pets, mother’s age, history of allergic diseases, smoking during pregnancy, and annual household income.

Results: No significant association was found between PM_2.5 and its component concentrations and asthma. However, wheezing significantly increased with mean NO₃⁻ concentrations during pregnancy (odds ratio of 1.64 [95% confidence interval: 1.10, 2.47] for an interquartile range increase). Significant associations were also found between EC in the second trimester of pregnancy and PM_2.5, NO₃⁻, EC, and OC concentrations in early childhood. Higher PM_2.5, SO₄⁻, and NH₄⁺ concentrations during the second trimester increased the risk of rhinitis. Sensitizations to HDM and animal proteins were significantly associated with exposure to components such as SO₄²⁻ and NH₄⁺ during pregnancy but not with postnatal exposure.

Conclusions: Exposures to NO₃⁻, EC, and OC during pregnancy and early childhood were associated with wheezing. SO₄²⁻ and NH₄⁺ exposures during pregnancy were associated with sensitization to HDM and animal proteins. Asthma was not associated with exposure to PM_2.5 and its main components at any period.

Background: Both metabolic syndrome (MetS) and depression are high priority health problems, especially for working age. Numerous studies have explored the link between metabolic syndrome and depression; however, not all of them have consistently demonstrated an association. The objective of this study was to determine whether there is an association between MetS and depression by analyzing extensive real-world data (RWD).

Methods: Our data was drawn from insurance claims and health checkups of local government officials across all prefectures in Japan except for Tokyo in the 2019 fiscal year. According to the number of months with diagnosis of depression and prescription of antidepressants, the study participants were classified into the following categories: Certainly not Depression (CN), Possibly not Depression (PN), Possible Depression (PD), and Certain Depression (CD). Associations between MetS and its components—visceral obesity, hypertension, hyperlipidemia, and diabetes— and these categories of depression were analyzed by logistic regression.

Results: The depression categories of the 130,059 participants were as follows: CN 85.2%; PN 6.9%; PD 3.9%; and CD 4.1%. For men, the adjusted odds ratio (AOR) for MetS were PN 0.94 (95% CI: 0.86–1.02), PD 1.31 (1.19–1.43), and CD 1.63 (1.50–1.76), with reference to CN. For women, AOR of MetS were PN 1.10 (0.91–1.32), PD 1.54 (1.24–1.91), and CD 2.24 (1.81–2.78). Among the MetS components, visceral obesity, hyperlipidemia, and diabetes were significantly associated with depression categories.

Conclusions: In this study, we found a significant association between MetS and depression, this association being similar to that previously reported. Our findings provide robust evidence for linkage between MetS and depression, suggesting that analysis of RWD is useful for providing concrete evidence.

Background: Cadmium, a toxic metal, is widely encountered in diverse environmental contexts. Despite its pervasive exposure, there is limited research on the association between blood cadmium levels and depression, especially among females. This study aimed to investigate the relationship between blood cadmium levels and depression in adult women.

Methods: Data spanning 2005–2016 from the National Health and Nutrition Examination Survey (NHANES) were selected. Depression was diagnosed with the Patient Health Questionnaire (PHQ-9, score ≥10). Multiple logistic regression, multiple linear regression, and smoothed curve fitting were used to investigate the relationship between blood cadmium and depression. Subgroup analyses and interaction tests were performed to evaluate the stability of this association across populations.

Results: A total of 1,173 individuals were diagnosed with depression. The heightened prevalence of depression was linked to increased blood cadmium levels, a trend that persisted even after quartering blood cadmium. In the fully adjusted model, each incremental unit of blood cadmium was associated with a 33% rise in the prevalence of depression (OR = 1.33, 95% CI: 1.21–1.45). Participants in the highest quartile were 63% more likely to experience depression compared to those in the lowest quartile of blood cadmium (OR = 1.63, 95% CI: 1.15–2.30), and PHQ-9 score increased by 0.73 (β = 0.73, 95% CI: 0.30–1.17). This positive association may be relevant to the general population.

Conclusions: Blood cadmium levels are associated with depression in adult women, and this association varies by age and smoking status.

Background: Methylmercury (MeHg), the causative agent of Minamata disease, damages the cranial nervous system and causes specific sensory disturbances, especially hypoesthesia, in the extremities. However, recent reports demonstrate that patients with chronic Minamata disease conversely develop neuropathic pain in the lower extremities. Studies on our established Minamata disease model rats showed that MeHg-mediated neurodegeneration might induce neuropathic pain by over time through inducing rewiring with neuronal activation in the somatosensory cortex via microglial activation in the spinal dorsal horn.

Methods: In this study, the effects of gabapentin, a potentially effective treatment for neuropathic pain, was evaluated using this Minamata disease model rats. To further elucidate the mechanism of its medicinal effects, histochemical and biochemical analyses of the nervous system of Minamata disease model rats were conducted.

Results: Gabapentin treatment restored the reduction in the pain threshold caused by MeHg exposure in rats. Histochemical and biochemical analyses revealed that gabapentin showed no effect on MeHg-induced neurodegeneration in entire nervous system and microglial activation in the spinal dorsal horn. However, it was shown that gabapentin may reduce excessive synaptogenesis through its antagonist action on the alpha2-delta-1 subunit of calcium channels in the somatosensory cortex.

Conclusions: These results indicate that gabapentin may alleviated neuropathic pain in MeHg poisoning, as typified by Minamata disease, by reversibly modulation synaptic rewiring in the somatosensory cortex.

Background: Aristolochic acid nephropathy (AAN) is a rapidly progressive interstitial nephropathy caused by Aristolochic acid (AA). AAN is associated with the development of nephropathy and urothelial carcinoma. It is estimated that more than 100 million people worldwide are at risk of developing AAN. However, the underlying mechanisms driving renal deterioration in AAN remain poorly understood, and the treatment options are limited.

Methods: We obtained GSE27168 and GSE136276 series matrix data from the Gene Expression Omnibus (GEO) related to AAN. Using the R Studio environment, we applied the limma package and WGCNA package to identify co-differently expressed genes (co-DEGs). By GO/KEGG/GSVA analysis, we revealed common biological pathways. Subsequently, co-DEGs were subjected to the String database to construct a protein-protein interaction (PPI) network. The MCC algorithms implemented in the Cytohubba plugin were employed to identify hub genes. The hub genes were cross-referenced with the transcription factor (TF) database to identify hub TFs. Immune infiltration analysis was performed to identify key immune cell groups by utilizing CIBERSORT. The expressions of AAN-associated hub TFs were verified in vivo and in vitro. Finally, siRNA intervention was performed on the two TFs to verify their regulatory effect in AAN.

Results: Our analysis identified 88 co-DEGs through the “limma” and “WGCNA” R packages. A PPI network comprising 53 nodes and 34 edges was constructed with a confidence level >0.4. ATF3 and c-JUN were identified as hub TFs potentially linked to AAN. Additionally, expressions of ATF3 and c-JUN positively correlated with monocytes, basophils, and vessels, and negatively correlated with eosinophils and endothelial cells. We observed a significant increase in protein and mRNA levels of these two hub TFs. Furthermore, it was found that siRNA intervention targeting ATF3, but not c-JUN, alleviated cell damage induced by AA. The knockdown of ATF3 protects against oxidative stress and inflammation in the AAN cell model.

Conclusion: This study provides novel insights into the role of ATF3 in AAN. The comprehensive analysis sheds light on the molecular mechanisms and identifies potential biomarkers and drug targets for AAN treatment.

Background: Identifying treatment targets for sarcopenia is a public health concern. This study aimed to examine the association of nocturnal sleep duration and midday napping with the presence of sarcopenia in middle-aged and older adults, utilizing data from the China Health and Retirement Longitudinal Study in 2011 and 2015.

Methods: A sum of 7,926 individuals (≥40 years) took part in this study. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia. A self-reported questionnaire was used to collect data on nocturnal sleep duration and midday napping. Nocturnal sleep duration was categorized into three groups: short sleepers (<6 h), normal sleepers (6–8 h), and long sleepers (>8 h). Midday napping was coded as a dichotomous outcome (yes/no).

Results: The incidence of sarcopenia was 5.3% during the 4-year follow-up. Short sleep duration (<6 h) was substantially linked to an increased incidence of sarcopenia (OR: 1.50, 95% CI: 1.21–1.87) as compared to nocturnal sleep length (6–8 h). Adults with midday napping had a lower risk of developing sarcopenia than non-nappers (OR: 0.78, 95% CI: 0.63–0.95). We further found that short sleepers with midday napping did not have a significantly higher risk of subsequent diagnosis of sarcopenia compared to normal sleepers without midday napping.

Conclusion: These findings imply that short sleep duration in middle-aged and older persons is related to an increased incidence of sarcopenia. However, the adverse effect of short sleep duration on sarcopenia can be compensated by midday napping.

Background: To enhance tobacco control in Japan, the government set a future smoking rate target (smoking prevalence = 12% by 2022) arguing that the “smoking rate target is expected if only smokers who want to quit smoking now, actually quit”. However, ideally both those wanting to quit now and those who wanted to in the past will succeed in the future. We aimed to re-define smokers who intend to quit and estimate their number. We also examined determinants of intention to quit, including daily tobacco consumption and tobacco use categories (exclusive combustible cigarette users, exclusive heated tobacco product (HTP) users, and dual (combustible cigarette and HTP)) users.

Methods: Using data from the 2021 Japan ‘Society and New Tobacco’ Internet Survey, we analyzed 5,072 current smokers (had used combustible cigarettes or HTPs in the past 30 days) aged 20–80 years. Smokers who intend to quit were defined as total smokers who want to quit now, have previously attempted or previously wanted to quit. Log-Poisson regression models were used to calculate adjusted odds ratios (aORs) with 95% confidence intervals (95%CI) for intention to quit (current or current/past), adjusting for potential covariates such as tobacco use categories.

Results: Among current smokers, 40.6% want to quit now, 27.0% have previously attempted and 9.0% have previously wanted to quit. Smokers of over 20 tobacco sticks/day are less likely to want to quit now than 1–10 /day (aOR = 0.79, 95%CI = 0.71–0.87) and less likely to intend to quit (both current and past) (aOR = 0.93, 95%CI = 0.88–0.98). Exclusive HTP and dual users were more likely to intend to quit (both current and past) than exclusive combustible cigarette users (aOR = 1.09, 95%CI = 1.04–1.14) and (aOR = 1.07, 95%CI = 1.03–1.12).

Conclusions: In total, 76.6% of current smokers, were defined as having intention to quit (both current and past). Applying this percentage to the target calculation, Japan’s smoking rate target would be 3.9%, considerably lower than the current target of 12%. The Japanese government may have to revise the smoking rate target. Additionally, we found that the usage of HTPs reduces intention to quit smoking. These insights have implications for setting of smoking rate targets and regulating HTPs in different countries.

Background: The developing brains are sensitive to methylmercury (MeHg). However, the exposure to MeHg in baby foods and toddler meals remains unknown. This study aimed to determine MeHg intake from baby food or toddler meals, and to investigate the relationship with child hair total mercury (THg).

Methods: A total of 3 days of 24-hour dietary diet and hair samples were collected from 260 consenting children aged 0–5 years. We measured the concentrations of THg and MeHg in the diet and THg in the hair.

Results: The results of measuring THg were below both the method detection and method quantification limits or either of both in powdered milk (93.8%), 5–6 months (53.3%), and 7–8 months (39.5%). The median daily THg intake was 20.3 (95% confidence interval 0.72–232.5) ng/kgbw. MeHg was not detected in 213 samples with dietary THg concentrations below 1 ng/g. The MeHg concentration with THg concentrations of 1 ng/g or higher was 1.70 (0.87–6.21) ng/g, and MeHg percentage in THg was 90.0%. To estimate MeHg intake, we multiplied the THg concentration by 90.0%, resulting in an estimated MeHg intake of 18.3 (0.65–209.2) ng/kgbw/day. The THg in children’s hair was 1.05 (0.31–3.96) ppm, and a weak positive correlation was observed between hair THg and dietary MeHg (r = 0.170).

Conclusions: This study highlights the accurate estimation of MeHg intake in children using a duplicate method. Japanese children consume fish, the MeHg intakes exceeded the reference dose and/or provisional tolerable weekly intake in several children. Further discussion based on epidemiological data is required.

Background: Stair climbing is a readily available form of physical activity with potential cardiovascular benefits. This study aimed to investigate the association between stair climbing and numerous modifiable cardiovascular disease (CVD) risk factors.

Methods: In this cross-sectional study, we used data from 7282 Japanese people (30–84 years) residing in Suita City, Osaka. CVD risk factors and stair climbing frequency were assessed during the Suita Study health examination. Logistic regressions were used to calculate the odds ratios (ORs) and 95% confidence intervals (95% CIs) for CVD risk factors across stair climbing frequencies.

Results: After adjustment for age, sex, lifestyle, and medical conditions, stair climbing >60% of the time, compared to <20% of the time, was inversely associated with obesity, smoking, physical inactivity, and stress: ORs (95% CIs) = 0.63 (0.53, 0.75), 0.81 (0.69, 0.96), 0.48 (0.41, 0.55), and 0.67 (0.58, 0.78), respectively (p-trends < 0.05).

Conclusion: Stair climbing was inversely associated with obesity, smoking, physical inactivity, and stress; suggesting a potential role for cardiovascular disease prevention.