Masamichi Hanazato

Correlation between human maternal-fetal placental transfer and molecular weight of PCB and dioxin congeners/isomers.

Establishing methods for the assessment of fetal exposure to chemicals is important for the prevention or prediction of the childs future disease risk. In the present study, we aimed to determine the influence of molecular weight on the likelihood of chemical transfer from mother to fetus via the placenta. The correlation between molecular weight and placental transfer rates of congeners/isomers of polychlorinated biphenyls (PCBs) and dioxins was examined. Twenty-nine sample sets of maternal blood, umbilical cord, and umbilical cord blood were used to measure PCB concentration, and 41 sample sets were used to analyze dioxins. Placental transfer rates were calculated using the concentrations of PCBs, dioxins, and their congeners/isomers within these sample sets. Transfer rate correlated negatively with molecular weight for PCB congeners, normalized using wet and lipid weights. The transfer rates of PCB or dioxin congeners differed from those of total PCBs or dioxins. The transfer rate for dioxin congeners did not always correlate significantly with molecular weight, perhaps because of the small sample size or other factors. Further improvement of the analytical methods for dioxin congeners is required. The findings of the present study suggested that PCBs, dioxins, or their congeners with lower molecular weights are more likely to be transferred from mother to fetus via the placenta. Consideration of chemical molecular weight and transfer rate could therefore contribute to the assessment of fetal exposure.

Correlating the symptoms of sick-building syndrome to indoor VOCs concentration levels and odour

Sick-building syndrome (SBS) is a range of symptoms such as eye irritation, sore throat, and headaches that occur when entering a newly constructed or refurbished building. Volatile organic compounds (VOCs) are suspected to be one of the major causes of SBS. However, although Ministry of Health, Labour, and Welfare of Japan set the guideline values for 13 VOCs, the incidences of SBS patients have not decreased. In addition, there have been reports that when people complained symptoms of SBS, most of them also claimed to smell an odour. Furthermore, the occurrence of SBS symptoms depends largely on the person’s sensitivity. In this study, the correlation between the sum of VOCs(C2-C16) including aldehydes (ΣVOCs) and SBS symptoms were examined by statistics. The odour was quantified using the odour threshold ratio (OTR) and the correlation between the total odour threshold ratio (TOTR: sum of the OTR) and SBS symptoms was investigated. These correlations were examined separately for sensitive and insensitive groups. TOTR and the concentration level of ΣVOCs were correlated with SBS symptoms among sensitive people. The findings indicate that TOTR, in addition to ΣVOCs, could be used as a new risk indicator for human health regarding indoor air quality.

Maternal–fetal transfer rates of PCBs, OCPs, PBDEs, and dioxin-like compounds predicted through quantitative structure–activity relationship modeling

The present study aims to predict the maternal–fetal transfer rates of the polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs), and dioxin-like compounds using a quantitative structure–activity relationship model. The relation between the maternal–fetal transfer rate and the contaminants’ physicochemical properties was investigated by multiple linear regression (MLR), partial least square regression (PLS), and random forest regression (RF). The 10-fold cross-validation technique estimated low predictive performances for both MLR and PLS models (R2CV = 0.425 ± 0.0964 for MLR and R2CV = 0.492 ± 0.115 for PLS) and is in agreement with an external test (R2pred = 0.129 for MLR and R2pred = 0.123 for PLS). In contrast, the RF model exhibits good predictive performance, estimated through 10-fold cross-validation (R2CV = 0.566 ± 0.0885) and an external test set (R2pred = 0.519). Molecular weight and polarity were selected in all models as important parameters that may predict the ability of a molecule to cross the placenta to the fetus.

Neighborhood Characteristics and Cardiovascular Risk among Older People in Japan : Findings from the JAGES Project

Previous studies have found an association between neighborhood characteristics (i.e., aspects of the physical and social environment) and the incidence of cardiovascular disease (CVD) and elevated CVD risk. This study investigated the relationship between neighborhood characteristics and CVD risk among older people in Japan where research on this association is scarce. Data came from the Japan Gerontological Evaluation Study project; questionnaire data collected from 3,810 people aged 65 years or older living in 20 primary school districts in Aichi prefecture, Japan, was linked to a computed composite CVD risk score based on biomarker data (i.e., hemoglobin A1c, systolic blood pressure, diastolic blood pressure, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and estimated glomerular filtration rate). A sex-stratified multilevel linear regression analysis revealed that for male participants, living in neighborhoods with a higher perceived occurrence of traffic accidents and reduced personal safety was associated with an elevated CVD risk (coefficient = 1.08 per interquartile range increase, 95% confidence interval [CI] = 0.30 to 1.86) whereas males living in neighborhoods with a higher perceived proximity of exercise facilities had a lower risk (coefficient = −1.00, 95% CI = −1.78 to −0.21). For females, there was no statistically significant association between neighborhood characteristics and CVD risk. This study suggests that aspects of the neighborhood environment might be important for CVD morbidity and mortality in Japan, particularly among men.

Aldehyde emissions from lime plaster containing vegetable oil

Lime plaster applied to walls and ceilings often contains vegetable oil for improving water resistance, and is considered to be harmless owing to its natural origin. The purpose of this study was to assess aldehyde emissions from plaster containing vegetable oil in order to predict the concentrations of aldehydes emitted into the indoor air. A passive emission chamber method was used to observe the emissions of aldehydes from vegetable oil when mixed with sodium hydroxide solution. The findings show that the alkalinity of calcium hydroxide in the plaster would accelerate the formation of aldehydes significantly. Furthermore, aldehyde emissions from the plaster to which vegetable oil was added were tested using a dynamic emission chamber (the small chamber method). A plaster containing soybean oil strongly emitted hexaldehyde throughout the test period. Plasters containing linseed oil or perilla oil strongly emitted propionaldehyde and acetaldehyde. The calculated indoor air concentrations of the aldehydes emitted from the lime plasters containing vegetable oil exceeded the air quality guidelines of the Japanese Ministry of Health, Labour, and Welfare, the Japanese Ministry of the Environment, and the German Federal Environmental Protection Agency. Moreover, these aldehydes are irritants and have unpleasant odours. Therefore, adding vegetable oil to plaster should be avoided to prevent sick-building syndrome.

Community-Level Sports Group Participation and Older Individuals’ Depressive Symptoms

PurposeCommunity-level group participation is a structural aspect of social capital that may have a contextual influence on an individual’s health. Herein, we sought to investigate a contextual relationship between community-level prevalence of sports group participation and depressive symptoms in older individuals. MethodsWe used data from the 2010 Japan Gerontological Evaluation Study, a population-based, cross-sectional study of individuals 65 yr or older without long-term care needs in Japan. Overall, 74,681 participants in 516 communities were analyzed. Depressive symptoms were diagnosed as a 15-item Geriatric Depression Scale score of ≥5. Participation in a sports group 1 d·month−1 or more often was defined as “participation.” For this study, we applied two-level multilevel Poisson regression analysis stratified by sex, calculated prevalence ratios (PR), and 95% confidence intervals (CI). ResultsOverall, 17,420 individuals (23.3%) had depressive symptoms, and 16,915 (22.6%) participated in a sports group. Higher prevalence of community-level sports group participation had a statistically significant relationship with a lower likelihood of depressive symptoms (male: PR, 0.89 (95% CI, 0.85–0.92); female: PR, 0.96 (95% CI, 0.92–0.99), estimated by 10% of participation proportion) after adjusting for individual-level sports group participation, age, diseases, family form, alcohol, smoking, education, equivalent income, and population density. We found statistically significant cross-level interaction terms in male participants only (PR, 0.86; 95% CI, 0.77–0.95). ConclusionsWe found a contextual preventive relationship between community-level sports group participation and depressive symptoms in older individuals. Therefore, promoting sports groups in a community may be effective as a population-based strategy for the prevention of depression in older individuals. Furthermore, the benefit may favor male sports group participants.