Environmental Health and Preventive Medicine最新文献

Background: Only prospective cohort studies can capture changes in work conditions and their effects on health. Such studies are rare in bus drivers, despite their high rates of injuries and diseases. The three existing cohorts have limited exposure data, collected at baseline and thus uninformative on exposure and exposure-effect dynamics. Therefore, we aimed to develop the Swiss Transport Personnel Health Cohort (TRAPHEAC) and to anticipate and prevent potential bias.

Methods: To set up the study protocol, we first organized the stakeholder consultation and available data inventory. Second, we mapped the exposure-outcomes pairs to list the most prevalent occupational hazards, and conducted exposure measurement campaigns. Third, we built the Swiss Bus-Exposure Matrix for physical-chemical hazards and Bus-Ergonomics Matrix for visual and biomechanical constrains. These matrices contain 705 bus models operated in Switzerland since 1980 and enable assessing current and past exposure when merged with bus drivers' work histories.

Results: We opted for an original study design combining prospective cohort part starting at 2024 and a retrospective part with nested case-control studies. Bus drivers will be invited through three complementary channels: unions, companies, and social media. The eligibility screening, information, and consent form signature and registration will be conducted using the study web-site modules. Registered bus drivers will first receive a comprehensive inclusion questionnaire, then a yearly follow-up questionnaire to assess and update the drivers' work histories. Validated self-reported questionnaires will be used for assessing additional health outcomes (e.g., stress, sleep problems, musculoskeletal disorders, burnout) and individual, occupational and live-style related factors (e.g., personality, ICT use, physical activity). Hospital records (with diagnosed diseases, diagnosis dates and treatments) centralized since 2000 by the Swiss Federal Statics Office will be used for assessing disease prevalence, incidence and case-control status. Advanced statistical analysis will be conducted to address etiological and methodological questions (e.g., individual and joint causal effects of multiple exposures and exposure components; time-varying exposure and outcome variables and confounders mixtures).

Conclusions: The yearly assessment of both exposure and health outcomes should enable capturing changes in work conditions and their effects on bus drivers' health and well-being over time and facilitate the tailoring, implementation and evaluation of preventive interventions.

Background: Hyperthermia (HT), while a cancer treatment approach, isn't always effective alone. Therefore, identifying hyperthermia enhancers is crucial. We demonstrated that Mito-TEMPO ([2-[(1-Hydroxy-2,2,6,6-tetramethylpiperidin-4-yl) amino]-2-oxoethyl]-triphenylphosphanium, MT) acts as a potent thermosensitizer, promoting cell death in human cervical cancer (HeLa) cells.

Methods: Cells were pretreated with 0.4 mM MT for 5 minutes, followed by exposure to hyperthermia (42 °C for 60 minutes). The impacts of MT/HT on cell viability, proliferation, apoptosis, endoplasmic reticulum (ER) stress, apoptosis-related proteins and autophagy, autophagy-related proteins expression were measured. The relationships between autophagy and apoptosis were further investigated using the specific autophagy inhibitor chloroquine (CQ) and the autophagy inducer rapamycin (Rapa).

Results: The combined treatment reduced the mitochondrial membrane potential (MMP) and increased ROS production. It also upregulated the pro-apoptotic protein Bax and downregulated anti-apoptotic proteins such as Bcl-2 and MCL-1. As a result, Caspase-3 was activated. Additionally, the combined treatment upregulated the expression of p-PERK/PERK, ATF-4, CHOP proteins. Moreover, the combined treatment also increased the expression of LC3 II and p62, decreased expression of LAMP 1 and Cathepsin D and increased lysosomal pH, indicating coordinated changes in autophagy regulation. Notably, intensification of apoptosis induced by the combined treatment was observed with CQ, whereas attenuation was seen with Rapa.

Conclusions: MT effectively enhanced HT-induced apoptosis in HeLa cells. Elevated ER stress and interruption of autophagy flux are the possible underlying molecular mechanisms for this phenomenon. These findings suggested MT can act as a potential thermosensitizer, highlighting its versatility in cancer treatment strategies.

Background: The long-term impact of symptom classification on quality of life (QOL) and economic outcomes among individuals with long coronavirus disease (COVID) remains poorly understood. This study aimed to clarify the situation of long COVID in Japan by analyzing patients using cluster classification.

Methods: This multicenter, retrospective cohort study enrolled 515 patients with COVID-19 and followed up for 36 months via standardized questionnaires. Patients were classified based on: 1) symptom trajectory over time and 2) symptom cluster profiles at 3 months.

Results: While the number of symptoms decreased, fatigue and dyspnea frequently persisted, whereas anosmia and dysgeusia declined. Cough and sputum decreased gradually. The proportion of patients with 5-9 symptoms increased. The mean (interquartile range) presenteeism scores were lower in the continuous (60 [50-80]) and relapse groups (65 [48-80]) than in the recovered group (70 [50-80]). The multiple symptoms cluster had the worst SF-36, presenteeism, and absenteeism scores (47.2 [44.7-49.8], 48.8 [27.5-72.5], and 10.9 [0.0-11.0], respectively).

Conclusions: Patients with continuous and multiple symptoms experienced persistently lower QOL and greater economic burden up to 36 months after COVID-19 diagnosis. The long-term effects of long COVID are not only physical but also mental and economical. Thus, further research is needed to clarify the economical and physiological impact of long COVID.

Background: Epstein-Barr (EB) virus infection stimulates the production of vascular endothelial growth factor (VEGF), which contributes to the progression of angiogenesis. Angiogenesis plays an important role in the development of atherosclerosis. Since serum anti-early antigen EB virus IgG (EBV EA-IgG) titer is a sign of active EB virus infection, EBV EA-IgG titer could be associated with atherosclerosis. The number of minor (T) alleles in VEGF polymorphism rs3025039 has been reported to be inversely associated with serum VEGF concentration, suggesting that rs3025039 might have a strong influence on the association between EBV EA-IgG titer and atherosclerosis. By focusing on the role of VEGF in the development of atherosclerosis, this study aimed to investigate the association between active EB virus infection and atherosclerosis.

Methods: A cross-sectional study of 2,661 older Japanese individuals aged 60-89 years who participated in annual health check-ups during 2017-2019 was conducted. Logistic regression was used to evaluate the association between EBV EA-IgG titer and atherosclerosis in relation to rs3025039 genotype. The influence of rs3025039 (T) allele carrier status on the association between EBV EA-IgG titer and atherosclerosis was also evaluated by using logistic regression.

Results: Among rs3025039 CC-homozygotes, with the lowest EBV EA-IgG titer tertile as the reference, the multivariable odds ratio (95% confidence interval) was 1.11 (0.82, 1.50) for the medium tertile and 1.07 (0.78, 1.47) for the high tertile. Among rs3025039 (T) allele carriers, the corresponding values were 1.44 (0.88, 2.36) and 1.88 (1.15, 3.05), respectively. There was a significant interaction between rs3025039 (T) allele carrier status and the association between EBV EA-IgG titer and atherosclerosis (adjusted p = 0.0497).

Conclusion: EBV EA-IgG titer was significantly positively associated with atherosclerosis only among participants who are genetically less likely to have progressive angiogenesis. An angiogenesis-related genetic factor was revealed as a determinant of the association between EBV EA-IgG titer and atherosclerosis. These findings introduce a novel concept that could explain the association between viral infection and atherosclerosis.

Background: Japan lacks comprehensive reports on the nationwide voluntary vaccine coverage. The effectiveness of public subsidies in promoting vaccination has not been fully investigated. Therefore, we aimed to estimate the nationwide coverage of voluntary vaccines, compare it with that of national immunization program (NIP)-included vaccines, and investigate the effectiveness of public subsidies.

Methods: We obtained nationwide monthly vaccine market data for rotavirus, Haemophilus influenzae type b (Hib), diphtheria, tetanus toxoid, acellular pertussis, inactivated poliovirus (DTaP-IPV), and mumps vaccines; estimated recipient numbers; and calculated coverage as the proportion of children from October 2011 to March 2022. Regarding the NIP-included vaccine, we compared vaccine coverage calculated from nationwide annual market data with that estimated by World Health Organization (WHO)/United Nations Children's Fund (UNICEF), using Bland-Altman analysis.

Results: The estimates of Hib and DTaP-IPV vaccine coverage derived from market data were slightly higher than the WHO/UNICEF estimates, with mean differences of 0.05 (95% CI: 0.02-0.07) for Hib and 0.03 (95% CI: 0.01-0.05) for DTaP-IPV. The coverage of the rotavirus vaccine gradually increased long before the implementation of national subsidies, reaching 0.9 in 2020. Hib vaccine coverage had already achieved 1.0 by January 2012. The coverage of the DTaP-IPV vaccine was approximately 0.6-0.8 in 2013, reaching 1.0 in 2014. The coverage of mumps vaccine increased gradually from 2011 to 2021.

Conclusions: Despite the possibility of overestimation, our estimates may serve as a valuable surrogate for actual vaccine coverage in Japan. An increasing trend in rotavirus and mumps vaccine coverage was observed when these vaccines were categorized as voluntary. Although vaccination policies differ from country to country, it would be beneficial to share findings on the impact of subsidies in Japan with other countries.

Background: Neck cooling is a practical method for preventing heat-related illness, however, its effectiveness in general workers is not well established. This study aimed to assess the effects of neck cooling on core body temperature and other physiological markers during exercise in a hot environment.

Methods: This randomized crossover trial was conducted from November 2023 to April 2024 at the Shared-Use Research Center at UOEH. Fourteen healthy adult males participated in the study under two conditions: with neck cooling (COOL) and without neck cooling (CON). All participants completed both conditions, and the order of condition assignment was determined by a random draw. Participants first rested for 10 minutes in a 28.0 °C, 50% relative humidity environment, followed by a rest in a 35.0 °C, 50% relative humidity environment for another 10 minutes. In the COOL condition, participants wore a neck cooler containing 1,200 g of ice while exercising at 50% Heart Rate Reserve on a bicycle ergometer for 20 minutes. Afterward, they rested for 15 minutes in the hot environment while still wearing the cooler.

Main outcome measures: Core body temperature (rectal and esophageal), forehead skin temperature, and heart rate were continuously monitored and compared using a mixed model. Estimated sweat volume was calculated based on changes in body weight before and after the experiment.

Results: At the end of the rest period, no significant differences were observed between the COOL and CON conditions in rectal temperature (37.76 ± 0.18 °C versus 37.75 ± 0.24 °C, p = 0.9493), esophageal temperature (37.75 ± 0.30 °C versus 37.76 ± 0.23 °C, p = 0.7325), forehead skin temperature (36.87 ± 0.29 °C versus 36.88 ± 0.27 °C, p = 0.2160), or heart rate (104.18 ± 7.56 bpm versus 107.52 ± 7.40 bpm, p = 0.1035). Estimated sweat loss was similar between conditions (578 ± 175 g for CON versus 572 ± 242 g for COOL, p = 0.5066). While more participants felt cooler in the COOL condition, RPE showed no significant difference.

Conclusion: Neck cooling did not significantly affect core temperature or perceived exertion. Maintaining close contact with the skin at sufficiently low temperatures or utilizing cooling methods that prevent excessive negative feedback may be necessary to enhance the effectiveness of neck cooling.

Background: Difficulty in chewing has been shown to be associated with increased mortality, geriatric syndromes, and poor activities of daily living, indicating the need for intervention. Chewing difficulties are related to tooth loss, periodontitis, dry mouth, and a number of oral health conditions. Diabetes mellitus (DM) is one of the major causes of global burden of diseases, and has been associated with poor oral health. Prospective association between oral health status and the development of diabetes has also been reported. However, relationship between glycemic control and self-reported chewing difficulty remains less explored in working-age populations. The objective of this study is to cross-sectionally explore the association between fasting blood glucose (FBG) and self-reported chewing difficulty in adults working in a Japanese worksite.

Methods: Participants from the Aichi Workers' Cohort Study who responded to the 2018 survey were included. Participants were categorized into five FBG groups (<100, 100-109, 110-125, 126-159, and ≥160 mg/dl). Multivariable odds ratios (ORs) and 95% confidence intervals (CIs) for chewing difficulty were estimated using logistic regression adjusted for age, sex, body mass index, smoking and alcohol consumption status, number of teeth, presence of periodontal disease and the number of anti-diabetic medication classes.

Results: A total of 164 participants (4.2%) reported difficulty with chewing, the prevalence of which tended to increase with increasing FBG level. FBG ≥160 mg/dl was significantly and strongly associated with difficulty with chewing in the final multivariable model (multivariable OR 3.84 [95% CI 1.13-13.0]).

Conclusions: A relationship between higher FBG levels and difficulty with chewing was observed, independent of potential confounding factors. However, prospective or interventional studies are needed to determine causality.

Background: Premature menopause, defined as natural menopause before age 40, is associated with diminished ovarian reserve. Despite growing concerns regarding environmental pollutants, no large-scale population-based studies have systematically examined the association between urinary polycyclic aromatic hydrocarbon metabolites (UPAHMs) and premature menopause.

Methods: This cross-sectional study analyzed 2001-2020 NHANES data, including urinary levels of six PAH metabolites: 1-naphthol (1-NAP), 2-naphthol (2-NAP), 3-fluorene (3-FLU), 2-fluorene (2-FLU), 1-phenanthrene (1-PHE), and 1-pyrene (1-PYR). Premature menopause was self-reported as natural menopause occurring before age 40. Multivariable logistic regression assessed UPAHMs' association with premature menopause, with restricted cubic splines (RCS) evaluating nonlinear trends. Subgroup analyses examined demographic interactions.

Results: Among 2,565 participants, 662 reported premature menopause. Multivariable logistic regression showed significant associations between elevated urinary levels of 1-NAP (OR: 1.01, 95% CI: 1.00-1.02, P = 0.02), 2-NAP (OR: 1.01, 95% CI: 1.00-1.02, P = 0.02), and 3-FLU (OR: 1.03, 95% CI: 1.01-1.05, P = 0.01) and increased risk of premature menopause. RCS analysis revealed significant nonlinear relationships for 2-NAP, 3-FLU, 2-FLU, 1-PHE, and 1-PYR with premature menopause risk. White participants showed greater susceptibility to UPAHMs.

Conclusion: Elevated UPAHMs, particularly 1-NAP, 2-NAP, and 3-FLU, were linked to higher premature menopause risk, with nonlinear trends observed. White individuals demonstrated greater vulnerability, emphasizing the need for targeted interventions to reduce PAH exposure.

Background: Organic chemicals have been known to cause allergic diseases such as bronchial asthma and hypersensitivity pneumonitis; however, the possibility that they do not cause irreversible pulmonary fibrosis has not been considered. Polyacrylic acid (PAA), an organic chemical, has caused irreversible progressive pulmonary fibrosis in exposed workers, indicating its potential to induce pulmonary inflammation and fibrosis. Although intratracheal instillation studies are commonly used for evaluating lung pathology, traditional methods face challenges with chemical substances, particularly nanoparticles, which tend to aggregate in suspension and prevent uniform pulmonary distribution. Such aggregation alters the qualitative and quantitative responses to lung injury, limiting accurate assessment of lung pathology. To overcome this limitation, we developed a 'molecular dispersion method' that uses pH modification to negative charges to PAA particles, maintaining their dispersion. Using this method, we investigated the effects of PAA on pulmonary inflammation and fibrosis in a rat model.

Methods: F344 rats were intratracheally instilled with PAA using molecular dispersion (0.1 mg/rat, 1.0 mg/rat), PAA without molecular dispersion (1.0 mg/rat), and normal saline (control group). Rats were sacrificed at 3 days, 1 week, 1 month, 3 months, and 6 months after exposure to examine inflammatory and fibrotic responses.

Results: PAA caused persistent increases in neutrophil influx in the bronchoalveolar lavage fluid (BALF) from 3 days to 1 month following instillation. In histopathological findings, the group with molecular dispersion had almost no inflammatory masses in the lung tissue compared to the group without molecular dispersion, and exhibited relatively uniform dispersion.

Conclusion: Intratracheal instillation of dispersed PAA induced neutrophil inflammation and fibrosis in the rat lung, suggesting that PAA might have pulmonary inflammogenicity and fibrogenicity. Intrapulmonary dispersion of PAA particles following intratracheal instillation studies using the molecular dispersion method was similar to that following inhalation studies.