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Background: Lifelong health is dependent on prenatal growth and development, influenced by the placental intrauterine environment. Charged with dual functions--exchange of oxygen and nutrients as well as a barrier against toxins--the placenta itself is susceptible to environmental exposure to heavy metals., Objective: To examine the use of placenta weight as a biomarker for heavy metal exposure using a large Japanese cohort of pregnant women., Methods: The placenta weight, as a biomarker of exposure to heavy metals (cadmium, lead, and mercury), was investigated using data from the Japan Environment and Children's Study (2011-2014). Selenium and manganese were included as factors directly affecting fetal growth or heavy metal toxicity. Maternal blood samples collected in the second or third trimester were used to measure heavy metal concentrations. The association between maternal blood metal concentrations and placenta weight was explored by applying Z scores and multivariable logistic regression analysis and classifying participants into quartiles (Q1, Q2, Q3, and Q4) according to metal concentrations., Results: This study included a total of 73,005 singleton pregnant women who delivered via live births and met the inclusion criteria. The median heavy metal concentrations in the maternal whole blood were 0.662 ng/g cadmium, 5.85 ng/g lead, 3.61 ng/g mercury, 168 ng/g selenium, and 15.3 ng/g manganese. Regression analysis revealed a significant correlation between placenta weight Z scores and maternal blood metal concentrations: cadmium, 0.0660 (standard error = 0.0074, p < 0.001); selenium, -0.3137 (standard error = 0.0276, p < 0.001); and manganese, 0.1483 (standard error = 0.0110, p < 0.001)., Conclusion: This study provides a robust examination of the association between heavy metal exposure and placenta weight. Cadmium and manganese showed a positive correlation with significant differences, whereas selenium showed a negative correlation. Essential elements notably affect placenta weight differently. No significant association was noted between lead or mercury and placenta weight., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Fish are a rich source of essential nutrients that protect against preterm birth. However, as fish can absorb environmental pollutants, their consumption can also increase the risk of preterm birth. This study aimed to assess whether maternal fish consumption during pregnancy is associated with preterm birth in a nationwide large Japanese cohort that consumed relatively high amounts and many types of fish., Methods: This study included 81,428 mother-child pairs enrolled in a nationwide prospective Japanese birth cohort study. Fish consumption was assessed using a validated food frequency questionnaire. Multivariate logistic regression was used to investigate the association of total consumption of fish, fatty fish and lean fish, fish paste, and seafood and clams with preterm birth, adjusted for potential confounders., Results: There was no association between overall fish consumption and preterm births. However, the highest quintile of fish paste consumption was significantly associated with an increased risk of preterm birth (odds ratio [OR]: 1.11; 95% confidence interval [CI: 1.04, 1.17]). The consumption of baked fish paste at least three times per week was significantly associated with preterm birth (OR: 1.20; 95% CI: 1.03, 1.40). Consumption of other types of fish, except fish paste, was not significantly associated with preterm birth risk., Conclusions: Fish paste consumption may increase the risk of preterm birth. Further studies are required to confirm this association.

Objectives: The mask fit test confirms whether the wearing condition of the wearer's face and the facepiece of the respirators are used appropriately. This study aimed to examine whether the results of the mask fit test affect the association between the concentration of metals related to welding fumes in biological samples and the results of time-weighted average (TWA) personal exposures., Methods: A total of 94 male welders were recruited. Blood and urine samples were obtained from all participants to measure the metal exposure levels. Using personal exposure measurements, the 8-h TWA (8 h-TWA) of respirable dust, TWA of respirable Mn, and 8-h TWA of respirable Mn were calculated. The mask fit test was performed using the quantitative method specified in the Japanese Industrial Standard T8150:2021., Results: Fifty-four participants (57%) passed the mask fit test. Only in the Fail group of the mask fit test, it was observed that blood Mn concentrations be positively associated with the results of TWA personal exposure after adjusting for multivariate factors (8-h TWA of respirable dust; coefficient, 0.066; standard error (SE), 0.028; P = 0.018, TWA of respirable Mn: coefficient, 0.048; SE, 0.020; P = 0.019, 8 h-TWA of respirable Mn: coefficient, 0.041; SE, 0.020; P = 0.041)., Conclusions: The results clarify that welders with high concentrations of welding fumes in their breathing air zone are exposed to dust and Mn if there is leaking air owing to the lack of fitness between respirators and the wearer's face when using human samples in Japan., (© 2023 The Authors. Journal of Occupational Health published by John Wiley & Sons Australia, Ltd on behalf of The Japan Society for Occupational Health.)

Objectives: Although gender stereotypes regarding paid work and unpaid work are changing, most wives are responsible for taking care of the family and home in Japan. It is unclear how time spent on housework and childcare has changed between working men and women during the COVID-19 pandemic in Japan. The purpose of this study is to investigate how working men and women's responsibilities for housework and childcare changed during the COVID-19 pandemic in Japan depending on work hours, job type, the number of employees in the workplace, and frequency of telecommuting., Methods: A cross-sectional analysis (N = 14,454) was conducted using data from an Internet monitoring study (CORoNa Work Project), which was conducted in December 2020. A multilevel logistic model with nested prefectures of residence was conducted to estimate the odds ratio (OR) for change in time devoted to housework and childcare among men and women adjusting for age, household income, presence of spouse who work, work hours, job type, the number of employees in the workplace, frequency of telecommuting, and the incidence rate of COVID-19 by prefecture., Results: More women tended to perceive that their time of housework and/or childcare had been changed (increased housework: OR 1.92, 95% CI [1.71-2.16], P < .001; decreased workhours: 1.66 (1.25-2.19), P < .001: increased childcare: OR 1.58, 95% CI [1.29-1.92], P < .001; decreased childcare: 1.11 (0.62-2.00), P = .719)., Conclusions: The time spent by women on housework and childcare changed significantly compared to men during the COVID-19 pandemic in Japan., (© 2022 The Authors. Journal of Occupational Health published by John Wiley & Sons Australia, Ltd on behalf of The Japan Society for Occupational Health.)

Previous cross-cultural studies of shyness have generally reported a higher level of shyness among adults in Japan than in the United States. This study examined two aspects of culture potentially related to different levels of shyness among the Americans and the Japanese: complementary relationship orientation, a tendency to maximize the status difference during communication, and family interdependence, a dependent tendency between a child and a parent. The survey included the 13-item version of Cheek's Shyness Scale and Sakuragi's Complementary Relationship Orientation Scale, and the Family Interdependence Scale. Analysis of responses by 166 American university students (76 men, 90 women) and 187 Japanese (81 men, 106 women) indicated that complementary relationship orientation was significantly related to shyness for both the Americans and the Japanese. No significant relationship, however, was found between scores on family interdependence and shyness.

A clinical and histopathological investigation was made on 170 patients with bladder cancer who underwent total cystectomy at our institutions between 1982 and 1986. The overall 5-year survival rates of patients with pTis + pTa, pT1, pT2, pT3, pT3b and pT4 were 100, 71.8, 60.7, 39.2, 31.4 and 0% respectively, those of patients with G1, G2 and G3 were 100%, 67.6%, 35.7% respectively. As for histopathological growth and spread pattern (INF), intramural lymphatic invasion (ly) and venous invasion (v), INF beta, INF gamma, ly2, v (+) showed the worst prognosis. These histopathological factors were considered to be closely correlated to each other. Studies on these histopathological factors are very important in planning the subsequent therapy.