No abstract

Summar yThis study compares and analyzes the long-term trends of the currently published emissions of chemical substances and environmental monitoring results, and evaluates the impact of changes in emissions on air concentrations using Tokyo as a case study. In this study, we first estimated the emissions to the atmosphere of estimated releases of outside notification, for which no data by emission media were available, and analyzed them in combination with reported emissions. As a result, it was found that the emission categories that contributed to the reduction of atmospheric concentrations differed depending on the substance, reflecting the results of various emission control measures that have been taken for each substance. The analysis using the data reported on the use of chemical substances in the metropolitan government s ordinances suggests that the reduction in emissions was not due to the promotion of exhaust gas treatment (introduction of treatment equipment, etc.), but rather to the reduction in the amount of chemical substances used. When the toxicity weighted emissions of the released chemical substances was calculated, it was also estimated that the risk of formaldehyde and acrolein was large, which was significantly different from the top-ranking substances in terms of emissions. These analyses using published data can be carried out by the administrative departments of each local government, and this study proposed a method for understanding the status of air quality improvement in the region that can be implemented by the government.

Summar yIn this study, we analyzed the estimation accuracy of the annual average value of volatile organic compounds (VOCs) in the atmosphere according to the measurement frequency. As the analysis data, VOCs continuous monitoring data that has been observed hourly for years at points in Tokyo was used. In the case of -hours sampling, the coefficient of variation (CV) of the annual average value in the -days cycle to accurate annual average was . on average substances. On the other hand, when the measuring day of the week is fixed, as in the case of the -days cycle, there were substances that had a significantly higher CV. Especially for trichloroethylene and dichloromethane, it was higher than that in the -days cycle. It was considered that this is influenced by the concentration fluctuation due to industrial and/or traffic activities, and it was speculated that if the measuring day of the week was fixed even once a month, the accuracy of the annual average value would decrease. In the monthly monitoring, the CV of the annual average value for one-week sampling was smaller than for the -hours sampling. It was estimated that the monitoring times per year with one-week sampling was the same level or less than the CV of the monitoring times per year with the -hours sampling. The annual average value by -week sampling of times per year was as accurate as the value obtained by -hours sampling of times per year that was commonly performed in Japan.