Long-term spatiotemporal variation of benzo[a]pyrene in Japan: Significant decrease in ambient concentrations, human exposure, and health risk.

Although Benzo[a]pyrene (BaP) is considered carcinogenic to humans, the health effects of exposure to ambient levels have not been sufficiently investigated. This study estimated the long-term spatiotemporal variation of BaP in Japan over nearly two decades at a fine spatial resolution of 1 km. This study aimed to obtain an accurate spatiotemporal distribution of BaP that can be used in epidemiological studies on the health effects of ambient BaP exposure.

Association of air pollution exposure during pregnancy and early childhood with children's cognitive performance and behavior at age six.

Background: The impact of air pollution on neurodevelopment in children has attracted much attention in recent times. We aim to clarify the association between prenatal and postnatal air pollutant exposure and children's cognitive performance and behavior at age six.

Methods: This study was conducted based on a birth cohort study in Japan.

Effectiveness of emission controls implemented since 2000 on ambient ozone concentrations in multiple timescales in Japan: An emission inventory development and simulation study.

It has been reported that ambient ozone concentrations in Japan have not been effectively suppressed by precursor emission controls. In this study, we developed an unprecedented long-term emission inventory of ozone precursors, including nitrogen oxide (NO) and volatile organic compounds (VOCs), in Japan. The developed emission inventory, which explicitly represents changes in emissions caused by emission controls and variation in activities from 2000 to 2019, revealed that emission controls implemented for vehicles, large point sources, and fugitive VOC sources effectively reduced precursor emissions.

Thirty-year simulation of environmental fate of Cs in the Abukuma River basin considering the characteristics of Cs behavior in land uses.

The Fukushima Daiichi Nuclear Power Plant accident caused a radioactive contamination of deposited radionuclides, including Cs, on the land surface. Cesium-137 deposited on the land surface was strongly adsorbed on soil particles and was then washed off through soil erosion. Trends of temporal variation of Cs wash-off varied greatly depending on land use.

Impact of soil erosion potential uncertainties on numerical simulations of the environmental fate of radiocesium in the Abukuma River basin.

The Fukushima Dai-ichi Nuclear Power Plant accident in March 2011 resulted in the deposition of significant quantities of radionuclides, including radiocesium (Cs), over a wide area. Most of the deposited Cs is strongly adsorbed on fine soil particles such as clay and silt near the ground surface. Therefore, to estimate the environmental fate of Cs, it is necessary to predict its transport with eroded sediment in rainfall-runoff processes.

Impact of field biomass burning on local pollution and long-range transport of PM in Northeast Asia.

Biomass burning (BB), such as, crop field burning during the post-harvest season, emits large amounts of air pollutants (e.g., PM) that severely impact human health.

Status and characteristics of ambient PM2.5 pollution in global megacities.

Ambient PM2.5 pollution is a substantial threat to public health in global megacities. This paper reviews the PM2.

Sensitivity analyses of factors influencing CMAQ performance for fine particulate nitrate.

Unlabelled: Improvement of air quality models is required so that they can be utilized to design effective control strategies for fine particulate matter (PM2.5). The Community Multiscale Air Quality modeling system was applied to the Greater Tokyo Area of Japan in winter 2010 and summer 2011.

Fog simulation using a mesoscale model in and around the Yodo River Basin, Japan.

In this study, fog simulations were conducted using the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) in and around the Yodo River Basin, Japan. The purpose is to investigate the MM5 performance of fog simulation for long-term periods. The simulations were performed for January, February, March, and July, 2005 with a coarse 3-km and a nested fine 1-km grid domains.