No abstract

In Japan, various countermeasures have been undertaken to reduce the atmospheric concentration of fine particulate matter (PM2.5). We evaluated the extent to which these countermeasures were effective in reducing PM2.5 concentrations by analyzing the long-term concentration trends of the major components of PM2.5 and their emissions in Nagoya City. PM2.5 concentrations decreased by 53% over the 16-year period from fiscal years 2003 to 2018 in Nagoya City. Elemental carbon (EC) was the component of PM2.5 with the greatest decrease in concentration over the 16 years, decreasing by 4.3 μg/m3, followed by SO42− (3.0 μg/m3), organic carbon (OC) (2.0 μg/m3), NH4+ (1.6 μg/m3), and NO3− (1.3 μg/m3). The decrease in EC concentration was found to be caused largely by the effect of diesel emission control. OC concentrations decreased because of the effects of volatile organic compound (VOC) emission regulations for stationary sources and reductions in VOCs emitted by vehicles and construction machinery. NO3− concentrations decreased alongside decreased contributions from vehicles, construction machinery, and stationary sources, in descending order of the magnitude of decrease. Although these findings identify some source control measures that have been effective in reducing PM2.5, they also reveal the ineffectiveness of some recent countermeasures for various components, such as those targeting OC concentrations.

Objective. It is recommended to reduce the greenhouse gases (GHG) for good environment action even when we buy fresh produce. The objective of this research is to calculate the amount of GHG emissions from fresh produce arriving in Nagoya City and also to analyze yearly variation in five years. Results and Discussion. We calculated the amount of GHG emissions about the level of production and transportation for 37 items(fruits, vegetables, meat and seafood) based on the amount of treatment in Nagoya Central Wholesale Market during 2008 ～ 2012. As a result, the amount of GHG emissions about the production level of the fruits and vegetables which was cultivated with heat was larger than that of the others and correlative to the amount of treatment. The GHG emissions from transportation process of the items that were transported from a distant place such as the Hokkaido or Tohoku regions were higher than those from the others. The annual amount of GHG emissions varied in response to annual national production or catch, and it was decreased over time for many items. Conclusions. The current work showed the amount of GHG emission of fresh produce in the level of production and transportation was vary greatly by heated cultivation or unheated cultivation and also the distance of transportation. It also showed the amount of GHG emission about many fresh produce is reducing over time.