We have been determinig atmospheric radioactive cesium ( 134 Cs and 137 Cs) concentrations in the early period after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in 2011 using suspended particulate matter (SPM) collected hourly on a filter tape at many automated SPM monitoring stations located widely in eastern Japan. The hourly atmospheric 134 Cs and 137 Cs concentrations just after the FDNPP accident in wide areas of eastern Japan were first revealed in our study. The determined 134 Cs and 137 Cs concentrations are expected to play an important role in reducing uncertainties of estimations of the internal radiation dose rates from inhalation and time-series radionuclides release rates from FDNPP, and an evaluation of the atmospheric transport models. There are four steps for the determination of radioactive cesium; i.e., identification of the date and time of SPM samples collected on filter-tapes, preparation of samples for gamma-ray measurement, measurement of gamma-rays, and calculation of concentrations and screening of their values. In this article, we introduced the technical methods to conduct the quality assurance through these four steps, based on our experience for about 7 years. detector was developed. The sample and reagent solutions in the reservoir on the degassed PDMS microfluidic device were autonomously flowed into the microchannel in the PDMS microfluidic device, since the degassed PDMS resin absorbs the air in the microchannel. The OPD was fabricated by a spin- coating method using poly(3-hexylthiophene-2,5-diyl) and [6,6]-phenyl-C61 butyric acid methyl ester as a material of photoelectric conversion layer. The measurement of hydrogen peroxide was evaluated using the chemiluminescence analysis system. SuperSignal TM ELISA Femto Substrate and Horseradish Peroxidase were used in the measurement. The calibration curve for hydrogen peroxide was linear for concentrations under 3.2 mM with a correlation coefficient of 0.9986. The limit of detection, defined as three-times the standard deviation of the blank signal, was estimated to be 4.4 μ M. Compared to the hydrogen peroxide assay kit using a 96-well microtiter plate and a micro plate reader, the amount of sample and reagent consumption and the analysis time could be reduced to 1/5 and 1/10, respectively. The chemiluminescence analysis system was successfully used in the determination of hydrogen peroxide in a commercially available disinfectant, oxydol. The chemiluminescence analysis system would be useful for on-site environmental measurement, quality control of food, point- of-care testing etc. since a pump is unnecessary and the detector is very small and lightweight. In order to clarify the impact of air pollution on the formation of sudden and locally distributed heavy rain in urban areas (hereafter UHR = urban-induced heavy rain), we analyzed inorganic ions concentration, dissolved and suspended fraction of trace metals, and stable isotope ratio of water ( δ D and δ 18 O) in rainwater samples collected from 2008 to 2016 in Tokyo. Acidic substance-derived components (H + , NH 4+ , NO 3– , nss-SO 42– ) have high concentrations in UHR, and acidic deposition increased locally along with rainfall amount near urban centers when UHR occurs. In addition, UHR has stable isotopes of hydrogen and oxygen smaller than normal rainfall, indicating that the influence of marine-derived water vapor was small. The concentration of air pollutants before the UHR was high, and secondary reaction rapidly progressed just before the UHR. Based on these results, we proposed the following UHR formation mechanism: (1) Air pollutants accumulate from the surrounding area into the area with the low atmospheric pressure due to the development of upflow by urban warming. (2) Due to oxidants formed by photochemical reactions, sulfate and nitrate that are produced secondarily from SO 2 and NO x become cloud condensation tuberculosis (CCN). (3) These CCNs generate many small cloud particles using water vapor evaporated from the urban area. (4) When the updraft is further developed, moist sea breezes containing sea salt particles, which are giant cloud condensations, flow in to form large cloud particles, which rapidly grow into raindrops due to collection with small water droplets.