The National Institute for Environmental Studies (NIES:国立環境研究所, Kokuritsu-Kankyō kenkyūsho) was established in 1974 as a focal point for environmental research in Japan. In 2001 it became an Independent Administrative Institution. NIES is organised into eight centers, each of which is subdivided into a further number of sections responsible for different specializations within the broader field to which they belong.The eight centers are responsible for research in eight different fields, with programs dedicated to these research areas.
Epidemiological evidence suggests that per-and polyfluoroalkyl substances (PFAS) exposure may attenuate antibody responses to vaccination. However, vaccine effectiveness as an outcome has not been investigated. This study assessed whether maternal PFAS concentrations during pregnancy modified childhood vaccine effectiveness. We analyzed mother-child pairs from the Japan Environment and Children's Study. Children's vaccination status for varicella, mumps, and influenza was collected via self-reported questionnaires at 2 years of age. Subsequent infection incidence was similarly assessed until 6 years for varicella and mumps, and 3 years for influenza. Maternal plasma samples collected during pregnancy provided PFAS measurements. Logistic regression models, incorporating interaction terms between vaccination status and PFAS concentrations, examined effect modification on both additive (relative excess odds due to interaction) and multiplicative (ratio of odds ratios) scales. Vaccinations were associated with reduced infection risk across PFAS exposure levels for all three diseases. Effect modification assessments revealed that perfluorononanoic acid (PFNA) significantly reduced varicella and mumps vaccine effectiveness on the additive scale. For mumps, the odds ratio for infection among unvaccinated versus vaccinated children (higher values indicate greater vaccine effectiveness) was higher in the lowest PFNA tertile than in the highest, with a relative excess odds due to interaction of 0.94 (95% confidence interval: 0.33-1.54, P = 0.0025). Multiplicative scale effect modifications were not statistically significant. Vaccinations reduced infections in children across all maternal PFAS exposure levels. Evidence of effect modification was limited, isolated, and inconsistent. These analyses are exploratory, and confirmation is warranted.
Per-and polyfluoroalkyl substances (PFAS) have raised concerns about their potential immunosuppressive effects. However, the association between prenatal PFAS exposure and childhood rubella remains unclear. This study examined whether prenatal PFAS exposure is associated with childhood rubella incidence. We analyzed data from the Japan Environment and Children's Study, including children whose mothers had plasma PFAS concentrations measured during pregnancy. The primary outcome was caregiver-reported physician-diagnosed rubella up to 6 years of age. Seven PFAS with detection frequencies >60% were analyzed. Logistic regression analyses were performed to evaluate associations between PFAS concentrations and rubella incidence. Age-stratified analyses were performed, mixture effects were evaluated using quantile g-computation, and a nested case-control sensitivity analysis using conditional logistic regression was conducted. Of 25,253 eligible children, 15,694 were included after excluding non-first-born children from multiple births and participants with missing data; 43 had caregiver-reported physician-diagnosed rubella. No significant associations were observed between maternal PFAS concentrations and childhood rubella incidence in either the regression or age-stratified analyses. Mixture exposure analyses also showed no significant association, and the nested case-control sensitivity analysis yielded similar findings. In conclusion, we did not find a statistically significant association between maternal PFAS exposure during pregnancy and childhood rubella incidence up to 6 years of age. However, the limited number of rubella cases reduced statistical power to detect modest associations, and larger studies are warranted.
Vehicle electrification is increasing demand for critical battery materials and shifting end-of-life management from whole vehicle scrap toward component-level streams, especially retired vehicle batteries. The five BRICS founding countries-Brazil, Russia, India, China, and South Africa-represent a critical and diverse testing ground for this transition because they combine large and growing vehicle markets, divergent electrification pathways, and uneven recycling capacities. Here, we develop a stock-driven dynamic material flow model to project vehicle electrification, end-of-life vehicle generation, and retired battery generation from 2025 to 2050. By combining material intensity data with country-specific end-of-life parameters, we estimate secondary material re-supply and vehicle-to-vehicle circularity for major vehicle and battery materials. By 2050, circularity for recoverable battery materials under current systems ranges from approximately 3 % to 24 % across countries and materials, indicating continued dependence on primary supply. Improved collection and refining can raise circularity for these materials to 24 %-56 %, with NiSO4 reaching approximately 49 %-56 % in China, South Africa, Russia, and Brazil; however, FeSO4, graphite, and carbon black remain unrecovered under the modeled conditions. Our analysis shows the need to synchronize electrification with formal collection, component-level dismantling, quality-preserving refining, and targeted policy support.
Abstract Nitrous oxide (N2O) is a strong greenhouse gas that contributes significantly to global warming and causes depletion of ozone in the stratosphere. Recent observational records show an unprecedented acceleration in atmospheric N₂O growth, reaching 1.15 ppb yr− 1 in 2019–2023, a significant increase compared to 0.68 ppb yr− 1 in 2001–2005. This surge in growth rate is particularly pronounced over tropical regions, and has been measured most prominently at the southern-most island of Japan (Hateruma). In this study, we use N2O observations from globally distributed multi-institutional networks and the MIROC4-ACTM inversion framework to quantify N2O emissions and identify key regions that are driving the recent acceleration. Our results suggest that the major Asian countries, Brazil, Central and Northern Africa, and the Contiguous United States have increased emission sources in the recent 2.5 decades (1998–2023). Further, there has been an increase in land N2O emissions, at a rate of 106 GgN yr− 1 per year during 1998–2002 to 2019–2023 (1Gg = 109g). The inversion inferred trends are consistent with increased fertiliser use and manure production to support extensive agriculture, and terrestrial ecosystem model results. The emissions from oceanic regions did not show significant increases in N2O (rate: 7 ± 2 GgN yr− 1 per year) in our inverse model setup. Our results underscore the importance for improved climate mitigation strategies and emissions reduction policies by increasing nitrogen-fertiliser use efficiency in agricultural land.
Heavy rainfall events can severely reduce salinity in enclosed seas and cause physiological stress to marine organisms such as bivalves, and their frequency and intensity have been in an increasing trend in recent years. In the study area, Nanao Bay, located on Noto Peninsula, Japan, several flood disasters associated with heavy rainfall occurred in recent years, and in some cases, extremely low salinity water was observed in the aquaculture ground. There is no river whose flow rate is monitored in the watershed, and the impact of heavy rainfall events on the environment of this bay remains to be fully understood. In this study, a coastal ocean model with a rainfall-runoff model was developed and optimized using the results of the field observations, and the influences of heavy rainfall events and winds on low salinity water dynamics and seawater exchange were numerically investigated. The results of the field observations showed the influence of two prevailing winds in this area on low salinity water dynamics; northeasterly winds caused low salinity water to stagnate at the bay head, while southwesterly winds quickly dissipated low salinity water. The results of the sensitivity experiments showed that estuary circulation was enhanced by southwesterly winds common in July–August while suppressed by northeasterly winds frequent in late summer. The coastal ocean model with the rainfall-runoff model well reproduced the low salinity water dynamics, suggesting that it would be useful for analyzing the impact of increased heavy rainfall on the coastal area.
