Environmental Health and Preventive Medicine最新文献

Background: Quick accomplishment and responsiveness are behaviors related to time management by perceived control of time, such as a positive feeling of using one's time well. In recent years, positive psychological states have been associated with a lower risk of cardiovascular disease (CVD). Thus, we investigated the associations of quick accomplishment and responsiveness with CVD mortality in a large cohort study.

Methods: The study participants were 75,049 (30,901 men and 44,148 women) aged 40-79 between 1988 and 1990 and followed until the end of 2009. Hazard ratios (HRs) and 95% confidence intervals (CIs) of mortality from CVD according to quick accomplishment, responsiveness, and their combination were calculated after adjustment for potential confounding factors using the Cox proportional hazard model.

Results: Quick accomplishment was associated with a lower risk of CVD mortality in women; a similar but marginally significant association was observed in men; the respective multivariable HR (95%CI) was 0.91 (0.83-0.99) and 0.93 (0.86-1.01). The presence of both quick accomplishment and responsiveness was associated with lower risk in men, which was confined to men aged 60-79; the respective multivariable HR (95%CI) was 0.88 (0.78-0.99) and 0.83 (0.72-0.96).

Conclusions: Quick accomplishment was associated with a lower risk of CVD mortality. Quick accomplishment and responsiveness combined were inversely associated with CVD mortality risk among older men.

Background: SARS-CoV-2 (COVID-19) is transmitted via infectious respiratory particles. Infectious respiratory particles are released when an infected person breathes, coughs, or speaks. Several studies have measured respiratory particle concentrations through focusing on activities such as breathing, coughing, and short speech. However, few studies have investigated the effect of speech duration.

Methods: This study aimed to clarify the effects of speech duration and volume on the respiratory particle concentration. Study participants were requested to speak at three voice volumes across five speech durations, generating 15 speech patterns. Participants spoke inside a clean booth where particle concentrations and voice volumes were measured and analyzed during speech.

Results: Our findings suggest that as speech duration increased, the aerosol number concentration also increased. Through focusing on individual differences, we considered there might be super-emitters who emit more aerosol particles than the average human. Two participants were identified as statistical outliers (aerosol number concentration, n = 1; mass concentration, n = 1).

Conclusions: Considering speech duration may improve our understanding of respiratory particle concentration dynamics. Two participants were identified as potential super-emitters.

Background: Technological innovations in the public transport sector are increasingly leveraged to support the goals of environmental sustainability and public health. Eco-driving assistance (EDA) systems represent one such intervention, aimed at reducing fuel consumption, emissions, and operating costs while improving passenger comfort. However, the potential unintended impacts of EDA technologies on driver health and well-being remain understudied. The EDA Trial, part of the EU-funded INTERCAMBIO project, seeks to evaluate whether the use of EDA systems may introduce new psychosocial stressors for professional drivers, with implications for occupational and public health.

Methods: The EDA tested in this trial is called "NAVIG". Buses will be assigned randomly. Operating EDA-equipped vehicle will be considered as intervention condition, operating vehicle without EDA as control. Each participant will be monitored for 10 working days maximum to accumulate at least 5 intervention shifts during the trial. Heart rate variability (HRV) will be continuously recorded during working hours to assess autonomous stress responses. The root mean square of successive differences (RMSSD) will be averaged over intervention and control shifts to enable within-subject comparisons between intervention and control conditions. Subjective stress levels will be evaluated using the self-report instruments: Cohen's perceived stress scale at baseline and visual analogous scale at baseline and daily. Moreover, neuroendocrine stress biomarkers (salivary cortisol and cortisone) will be collected repeatedly across shifts, as additional outcomes. Mixed-effects models with participant's ID as a random effect variable will be used to compare stress outcomes between EDA and non-EDA driving conditions. Models will be adjusted for potential confounders.

Results: A sample size of 26-40 participants was estimated to provide 80% power (α = 0.05) to detect differences of 12-15% between conditions. Ethical approval was obtained from the Swissethics (CER-VD 2024-01573), and participant recruitment is ongoing, with 27 drivers enrolled as of June 2025.

Conclusions: This study will provide empirical evidence on the potential health trade-offs associated with implementing eco-driving technologies in real-world settings. By assessing physiological and psychological stress responses to EDA, the trial supports a more integrated approach to environmental technology evaluation-one that considers not only energy efficiency but also the health and sustainability of the workforce.

Trial registration: The trial was registered in the ClinicalTrials.gov database (NCT06688721).

Background: The creatinine (Cre) concentration in urine is used as an adjustment factor in chemical exposure and nutritional intake assessments. Because Cre excretion varies by sex, age, race, and anthropometric measurements such as height and weight, developing a method suitable for estimating one-day Cre excretion is necessary. Accordingly, this study aimed to develop a predictive equation for individual one-day Cre excretion in Japanese school children.

Methods: Urine samples were collected from 113 boys and 91 girls (aged 6-12 years) from the Aichi Prefecture, Japan, who were free from diseases affecting the renal, muscle, or nervous systems. Urinary concentrations and one-day excreted amounts of Cre were measured and compared with the values obtained using previously reported equations or a fixed value, totaling 11 methods. Subsequently, we developed a new equation using machine learning and multiple regression analyses. Additionally, the estimated one-day sodium excretion value calculated using this equation was compared with the measured value.

Results: Among the 11 methods to predict Cre excretion, 7 overestimated-5 of which showed a positive trend bias with larger differences at higher average concentrations-and 3 underestimated-2 of which showed a negative trend bias with larger differences at lower average concentrations. A new machine learning model using sex, age, and body surface area (calculated from height and weight) yielded the most accurate prediction. Multiple regression analysis, which demonstrated the most accurate prediction, used sex, age, and body surface area as independent variables with or without the first void Cre concentration divided by urination duration from the previous night's urination to the first void. Moreover, the difference in one-day sodium excretion from first-void urine predicted using our newly developed Cre equation increased as the measured values increased.

Conclusions: Our study suggests that the estimation of one-day Cre excretion based on sex, age, and body surface area is most appropriate for Japanese schoolchildren, particularly in assessing their chemical exposure and dietary nutrient intake.

Trial registration: Trial registration is not applicable as this observational study did not involve any intervention or randomization requiring registration in a clinical trials registry.

Background: A comprehensive understanding of the epidemiology of pediatric out-of-hospital cardiac arrest (OHCA) occurring under school supervision is lacking. We aimed to comprehensively describe the characteristics and outcomes of OHCA among students in elementary schools, junior high schools, high schools, and technical colleges in Japan.

Methods: OHCA data from 2008-2021 were obtained from the SPIRITS study, which provides a nationwide database of OHCAs occurring under school supervision across Japan. We included cases in which resuscitation was attempted by emergency medical service personnel or bystanders. The cases were classified into three groups based on their etiology: cardiac, non-cardiac, and traumatic origin. The primary outcome was one-month survival with favorable neurological outcomes, defined as a Glasgow-Pittsburgh cerebral performance category of 1 or 2. The demographic characteristics, event details, and outcomes were compared across the three groups by using χ² tests for categorical variables and one-way analyses of variance for continuous variables.

Results: During the 14-year study period, 602 OHCA cases were confirmed, with 430 (71.4%) classified as cardiac, 91 (15.1%) as non-cardiac, and 81 (13.5%) as traumatic origin. Non-cardiac and traumatic cases were less likely to be witnessed at the time of arrest (46.2% and 42.0%, respectively) than cardiac cases (82.6%; p < 0.001). Initiation of cardiopulmonary resuscitation by bystanders was less common in non-cardiac and traumatic cases (62.6% and 42.0%, respectively) than that in cardiac cases (82.8%; p < 0.001). The delivery of defibrillation using public-access automated external defibrillators was also significantly less frequent in non-cardiac (3.3%) and traumatic cases (6.2%) than that in cardiac cases (59.8%; p < 0.001). Ventricular fibrillation (VF) as the first documented rhythm was observed in 77.9% of cardiac cases but was much less common in non-cardiac (5.5%) and traumatic cases (8.6%; p < 0.001). One-month survival with favorable neurological outcomes was significantly lower in non-cardiac (6.6%) and traumatic cases (0%) than that in cardiac cases (50.2%; p < 0.001).

Conclusions: OHCAs of cardiac origin were more frequently associated with VF and had relatively good prognoses. In contrast, OHCAs of non-cardiac and traumatic origins consistently resulted in poor outcomes, highlighting the critical importance of prevention strategies to reduce the occurrence of these incidents.

Background: High levels of attention-deficit/hyperactivity disorder (ADHD) traits are associated with various outcomes, including depressive symptoms, functional impairment, and low self-esteem. Additionally, individuals with high levels of ADHD traits are reported to be more adversely affected by fear of coronavirus disease 2019 (COVID-19). The current study aimed to examine whether the association between ADHD traits and outcomes was partially mediated by fear of COVID-19 using mediation analysis.

Methods: A cross-sectional study was conducted in a sample of university students in medical-related faculties (n = 1,166). ADHD traits, fear of COVID-19, depressive symptoms, functional impairment, and self-esteem were assessed using the adult ADHD Self-Report Scale, Fear of COVID-19 Scale, K6 Scale, Sheehan Disability Scale, and Rosenberg Self-Esteem Scale, respectively. We used linear regression analysis and the Paramed command in Stata to analyze whether fear of COVID-19 mediated the association between ADHD traits and outcomes.

Results: ADHD traits were significantly associated with outcomes. Regarding the impact of fear of COVID-19, the results revealed a significant association between ADHD traits and fear of COVID-19, and between fear of COVID-19 and outcomes. The results of the mediation analyses showed that the association between ADHD traits and outcomes was partially mediated by the fear of COVID-19 (depressive symptoms: direct effect B = 1.029, 95% confidence interval [CI] 0.878, 1.181, indirect effect B = 0.021, 95% CI 0.002, 0.040; functional impairment: direct effect B = 0.786, 95% CI 0.593, 0.979, indirect effect B = 0.033, 95% CI 0.005, 0.060; self-esteem: direct effect B = -1.052, 95% CI -1.226, -0.878, indirect effect B = -0.024, 95% CI -0.046, -0.002).

Conclusions: Developing preventive measures against the adverse impacts of pandemics like COVID-19 will be particularly important for individuals with high levels of ADHD traits in future.

Background: Studies have shown that married couples often share similar lifestyles, as well as lifestyle-associated conditions such as diabetes, hypertension, and hyperlipidemia. This study aims to prospectively investigate the association between an individual's development of a non-communicable disease and the subsequent development of the same condition in their spouse.

Methods: This population-based cohort study utilized 12 waves of annual prospective surveys from 2005 onwards in Japan, with a discrete-time design. A total of 9,417 middle-aged couples (18,834 participants; discrete-time observations = 118,876) were included. Each participant whose spouse had developed one of six conditions was propensity score-matched with five controls whose spouses had not been diagnosed with the condition: diabetes [n = 1374 vs n = 6870], hypertension [n = 2657 vs n = 13285], hypercholesterolemia [n = 3321 vs n = 16605], stroke [n = 567 vs n = 2835], coronary heart disease (CHD) [n = 1093 vs n = 5465] or cancer [n = 923 vs n = 4615]. Using conditional logistic regression, we assessed participants' development of the same condition within three years following their spouse's diagnosis.

Results: Participants whose spouses had developed diabetes, hypertension, hypercholesterolemia, or CHD were more likely to develop the same condition within three years. The odds ratios (ORs) and 95% confidence intervals (CIs) were: 1.96 (1.53-2.50), 1.20 (1.06-1.36), 1.63 (1.47-1.81) and 1.43 (1.05-1.95), respectively. No significant associations were observed in stroke [1.69 (0.80-3.58)] or cancer [1.08 (0.75-1.54)].

Conclusion: Spouses of individuals recently diagnosed with certain metabolic conditions are at a higher risk of developing those conditions themselves. These findings may provide valuable guidance for targeting and personalizing chronic disease screening and prevention efforts.

Background: Motion sickness is a common transportation issue worldwide. Vestibular dysfunction has been reported to be a key etiology of motion sickness. However, there are limited technologies for alleviating motion sickness.

Methods: The most appropriate frequency (Hz) and level (dBZ) of pure tone for modulation of vestibular function were determined by an ex vivo study using murine utricle explants. The preventive effects of the selected pure tone on motion sickness were then confirmed by using a beam balance test in mice. The alleviating effects of pure tone on motion sickness induced by a swing, driving simulator or real car were objectively assessed by using posturography and electrocardiography (ECG) and were subjectively assessed by using the Motion Sickness Assessment Questionnaire (MSAQ) in humans.

Results: The effect of short-term (≤5 min) exposure to a pure tone of 80-85 dBZ (= 60.9-65.9 dBA) at 100 Hz on motion sickness was investigated in mice and humans. A mouse study showed a long-lasting (≥120 min) alleviative effect on shaking-mediated exacerbated beam test scores by 5-min exposure to a pure tone of 85 dBZ at 100 Hz, which was ex vivo determined as a sound activating vestibular function, before shaking. Human studies further showed that 1-min exposure to a pure tone of 80-85 dBZ (= 60.9-65.9 dBA) at 100 Hz before shaking improved the increased envelope areas in posturography caused by the shakings of a swing, a driving simulator and a vehicle. Driving simulator-mediated activation of sympathetic nerves assessed by the heart rate variable (HRV) and vehicle-mediated increased scores of the MSAQ were improved by pure tone exposure before the shaking.

Conclusion: Since the exacerbated results of posturography and HRV reflect shaking-mediated imbalance and autonomic dysfunction, respectively, the results suggest that the imbalance and autonomic dysregulation in motion sickness could be improved by just 1-min exposure to a pure tone with daily exposable sound pressure levels.

Trial registration: Registration number: UMIN000022413 (2016/05/23-2023/04/19) and UMIN000053735 (2024/02/29-present).

Background: Prolonged occupational noise exposure poses potential health risks, but its impact on mitochondrial DNA (mtDNA) damage and methylation patterns remains unclear.

Method: We recruited 306 factory workers, using average binaural high-frequency hearing thresholds from pure-tone audiometry to assess noise exposure. MtDNA damage was evaluated through mitochondrial DNA copy number (mtDNAcn) and lesion rate, and mtDNA methylation changes were identified via pyrophosphate sequencing.

Results: There was a reduction in MT-RNR1 methylation of 4.52% (95% CI: -7.43% to -1.62%) among workers with abnormal hearing, whereas changes in the D-loop region were not statistically significant (β = -2.06%, 95% CI: -4.44% to 0.31%). MtDNAcn showed a negative association with MT-RNR1 methylation (β = -0.95, 95% CI: -1.23 to -0.66), while no significant link was found with D-loop methylation (β = -0.05, 95% CI: -0.58 to 0.48). Mediation analysis indicated a significant increase in mtDNAcn by 10.75 units (95% CI: 3.00 to 21.26) in those with abnormal hearing, with MT-RNR1 methylation mediating 35.9% of this effect.

Conclusions: These findings suggest that occupational noise exposure may influence compensatory increases in mtDNA content through altered MT-RNR1 methylation.

Background: Mitochondria, which harbor their own genome (mtDNA), have attracted attention due to the potential of mtDNA copy number (mtDNA-CN) as an indicator of mitochondrial dysfunction. Although mtDNA-CN has been proposed as a simple and accessible biomarker for metabolic disorders such as metabolic dysfunction-associated steatotic liver disease, the underlying mechanisms and the causal relationship remain insufficiently elucidated. In this investigation, we combined longitudinal epidemiological data, animal studies, and in vitro assays to elucidate the potential causal relationship between reduced mtDNA-CN and the development of steatotic liver disease (SLD).

Methods: We conducted a longitudinal study using data from a health examination cohort initiated in 1981 in Yakumo, Hokkaido, Japan. Data from examinations performed in 2015 and 2022 were analyzed, focusing on 76 subjects without SLD at baseline (2015) to assess the association between baseline mtDNA-CN and subsequent risk of SLD development. In addition, 28-day-old SD rats were fed ad libitum on a 45% high-fat diet and dissected at 2 and 8 weeks of age. Blood and liver mtDNA-CN were measured and compared at each feeding period. Additionally, in vitro experiments were performed using HepG2 cells treated with mitochondrial function inhibitors to induce mtDNA-CN depletion and to examine its impact on intracellular lipid accumulation.

Results: Epidemiological analysis showed that the subjects with low mtDNA-CN had a significantly higher odds ratio for developing SLD compared to high (odds ratio [95% confidence interval]: 4.93 [1.08-22.50]). Analysis of the animal model showed that 8 weeks of high-fat diet led to the development of fatty liver and a significant decrease in mtDNA-CN. A further 2 weeks of high-fat diet consumption resulted in a significant decrease in hepatic mtDNA-CN, despite the absence of fatty liver development, and a similar trend was observed for blood. Complementary in vitro experiments revealed that pharmacologically induced mitochondrial dysfunction led to a significant reduction in mtDNA-CN and was associated with increases in intracellular lipid accumulation in HepG2 cells.

Conclusions: Our findings suggest that reduced mtDNA-CN may contribute causally to SLD development and could serve as a convenient, noninvasive biomarker for early detection and risk assessment.