In this study, as a result of having investigated air pollutants including the mutagenic/carcinogenic substances at two sites (Dazaifu and Yurihama) simultaneously, it was suggested that Asian dust was found even on the day on which it was not announced by the Meteorological Agency, and transboundary pollution by the artificial origin occurred with or without Asian dust. These pollutions were found on the same days at the two sites. As the source of total polycyclic aromatic hydrocarbons (PAHs), the influence of coal/biofuel combustion was large in both Dazaifu and Yurihama on the day when highly concentration was observed. However, in Yurihama, even on the day when only low concentration was observed, the effect of coal/biofuel combustion was large. Furthermore, the mutagenic substances were also scattered at high concentrations on the same days at both sites. Moderate or strong correlations were found for all parameters for concentrations of total suspended particles, Fe, Pb, SO₄^2-, and total PAHs and mutagenicity with and without S9 mix at the two sites. It was suggested that Dazaifu and Yurihama were also susceptible to the transboundary pollutants from Mainland China, and it was inferred that the effect of this transboundary pollution was particularly large in Yurihama.

The application of bamboo charcoal as the water treatment material was investigated in this study. Surface functions on the surface of the bamboo charcoal were measured in laboratory experiment and the ratio of basic functional group was over 50% of the total functional groups on the bamboo charcoal surface. The bamboo charcoal was added into the artificial waste water containing organic substances, nitrogen and anionic surface active agent. After agitation for 4 hours, the concentrations of COD (chemical oxygen demand), T-N (total Nitrogen) and MBAS (methylene blue active substances) decreased to 83% and 63% and 30% of the initial concentrations, respectively. Adsorption isotherm of COD, T-N and MBAS fitted Freundlich formula. Two grams of bamboo charcoal were added to 1 L of actual wastewater and the actual wastewater was agitated once for a day. After 14 days, a reduction of 91% for COD, 54% for T-N and 100% for MBAS was observed.

The mercury concentration of river waters in Niigata Prefecture was studied for regional distribution, fluctuation factors, and speciation. We investigated 11 rivers in Niigata Prefecture four times a year. As a result, average concentrations of total mercury (T-Hg), and dissolved T-Hg in the river waters were 1.7 ng/L, and 0.29 ng/L, respectively. The average ratio of dissolved alkyl mercury concentrations to dissolved T-Hg concentrations were about 15%. The dissolved T-Hg concentrations had no observable regional differences. On the other hand, the T-Hg concentration in suspended solids (SS) was highest in the Seki River. The average T-Hg concentration in SS (SS-Hg) in the Seki River was 0.34 μg/g, whereas those in the other rivers ranged from 0.11 to 0.23 μg/g. The factor that increased SS-Hg concentration in the Seki River is considered to be the sediment originated from volcano. We investigated long-term fluctuations of T-Hg concentration in the Shinkawa River during April 2017 to March 2019. As a result, the average concentrations of dissolved T-Hg and particulate T-Hg in the Shinkawa River were 0.40 ng/L and 2.3 ng/L, respectively. The particulate T-Hg concentration was highly correlated with SS concentration.

Metal allergy due to accessories, dental implants, and other metal-based household products is one of the most common causes of contact dermatitis. Meanwhile, nylon, wool, and silk textile products are often dyed with mordant dyes and metal complex acid dyes that contain chromium and cobalt, which are recognized as allergic metals. In this study, elements present in 78 textile products (106 samples) made of nylon, wool, and silk were analyzed by X-ray fluorescence using a fundamental parameter method. Twenty elements were detected in one or more samples, and Cr and Co were detected in 66 and 40 samples, respectively. The Cr concentration was found to be high, and exceeded 1,000 μg/g in 49 samples, among which, five samples showed >10,000 μg/g of Cr. On the other hand, the Co concentration exceeded 1,000 μg/g in three samples, and no sample showed >10,000 μg/g of Co. Both Cr and Co were detected in dark-toned samples (black, gray, and navy blue), and were hardly detected in light-toned samples (pink and red). Elution tests using seven samples which contained Cr and Co at high concentrations (>10,000 and >1,000 μg/g, respectively) were performed using artificial sweat. The Cr concentrations in acidic sweat (pH 5.5) and alkaline sweat (pH 8.0) were found to be 0.17-170 and 0.36-82 ng/mL, respectively, while the Co concentrations were found to be 0.042-130 and 0.028-130 ng/mL, respectively. The differences in the elution tendencies observed from each textile might be due to differences in the chemical structures of dyes containing Cr or Co. In the case of samples investigated in this study, it is deemed that Cr and Co are not likely to cause contact dermatitis at concentrations eluted into the artificial sweat.

Oil spill accident from steel mill was caused by flood in August 2019 in Saga Prefecture, Japan. Since "oil odor problem" was happened in disaster area, the source estimation of oil odor was conducted using sensory evaluation and Gas Chromatography-Olfactometry (GC-O). By the sensory evaluation, the odor in disaster area was assigned as "odor of oil and sewage". To know in detail of the oil odor, environmental samples (oil absorption sheets) were collected and sensory compared with several fuel oils. As the result of evaluation, oil odor in 7 days after accident consisted of diesel oil (with/or kerosene) instead of spilled oil from steel mill. This result suggested that those fuel oils were also spilled from various sources (heating fuel for house and agriculture) around this disaster are during this flood. On the other hand, the oil absorption sheets in 12 days after accident did not showed odor of those fuel oils, and it showed weak odor of spilled oil from steel mill. It could be due to that these fuel oils spilled were evaporated within a few days under the summer weather, but spilled oil from steel mill which had heavier property was kept in environment.

Quantitative analysis of pharmaceuticals and personal care products (PPCPs) in three environmental medias (air, water, and sediment) were carried out via a network of regional environmental research institutes in five large cities (Tokyo, Nagoya, Hyogo, Osaka, and Fukuoka) in Japan. The study took place from FY2016 to FY2018 as a part of a risk assessment for aquatic organisms. Analysis data of water samples from the five cities were carried out at the Tokyo Metropolitan Research Institute for Environmental Protection. The risk assessment for aquatic organisms was carried out by comparing the sample data with the predicted no-effect concentrations (PNECs) gathered from various sources. Concentration levels of five chemicals (clarithromycin, erythromycin, diclofenac, carbamazepine, and triclosan) exceeded the PNECs in several water samples. Concentrations of antibiotics, such as clarithromycin, and antihistamines, such as fexofenadine, tended to be higher during January to February than during June to August. In contrast, concentrations of insect repellents such as N, N-diethyl-m-toluamide (DEET) tended to be higher during June to August than during January to February. The discharge sources of these chemicals would be effluents from plants, such as sewage treatment plants, that were not completely treated. Estimated PPCPs loads accumulated by inflow data of Tamagawa river were compared with measured load value in this study. For some of these chemicals, such as fexofenadine and diclofenac, estimated loads did not coincide with measured loads at sampling points along the Tamagawa River. These differences were thought to occur as the consumption of fexofenadine increased rapidly during the research period, and diclofenac photodegraded while flowing down the river.

Oil spill accident from steel mill was caused by flood in August 2019 in Saga Prefecture, Japan. As the disaster response, spilled oil which was floating on the flood water was recovered by oil absorption sheets. It was hypothesized that soil contamination by spilled oil might be avoided if the oil could be recovered before it contacted to soil. The paddy soil samples collected in oil contaminated area (clean up with oil absorption sheets, n=3), control areas (n=2), and used quench oil (spilled oil from steel mill) were employed for chemicals analysis. The analytical technique of Automated Identification and Quantification Systems with gas chromatography mass spectrometry (AIQS-GC) was applied for Comprehensive Target Analysis (CTA). As the result of chemical analysis, sterols, alkanes, PAHs (including native- and methylated-PAHs), and other compounds were detected in paddy soil samples. Only alkanes and PAHs were detected from used quench oil. No clear differences were found on alkanes and PAHs concentrations between paddy soils collected in oil contaminated area and control area. On the other hand, contribution of chemicals detected in paddy soils and used quench oil were clearly different. These results indicate that soil contamination by spilled oil could be avoided by the recovering of spilled oil using oil absorption sheets during it was floating on the flood water.

Microplastics (MP) can cause damage to ocean ecosystem. The environmental problems due to MP contamination is attracting worldwide attention. In this study, the survey was conducted to clarify the origin of MP obtained on various beaches of Sagami Bay from the viewpoint of chemical adsorption. There was no clear difference in the amount of Perfluorinated Compounds (PFCs) adsorbed on various MP materials. PS foam with a large surface area adsorbed more PFCs per unit weight than resin.

The amount of PFOS adsorbed on the MP collected on Kugenuma beach downstream Hikiji river, where PFOS concentration in the water sample was relatively high, was higher than that adsorbed on the MP collected from the other two beaches. The total rainfall for one month before sampling in autumn was higher than the annual average, and the amount of PFCs adsorbed on the MP in autumn was lower than that in other seasons. The amount of PFOS adsorbed on the MP was high in the river downstream from the middle of the Hikiji River.

Partition coefficient (Kd) of PFOS that obtained from the elution test used the collected MP was higher than the valve by adsorption test for unused MP. Apparent Kd of PFOS by the MP on Kugenuma beach and the river water at Hujimi bridge of Hikiji river was the same order as the valve that obtained from the elution test used the collected MP.

It has been clarified that the MP fragments flowed into the Hikiji river were adsorbed with PFOS and flowed down, and they were drifted to the Kugenuma beach.

Concentrations of 19 polycyclic aromatic hydrocarbons (PAHs) and 15 methylated derivatives (Me-PAHs) were determined in different solid waste and environmental samples collected from Japan and Vietnam. Total levels of PAHs and Me-PAHs were the highest in vehicular soot samples (12,000-800,000 ng/g), followed by settled dusts (940-1,700 ng/g), and ash samples (100-270 ng/g). Fingerprint profiles of PAHs and Me-PAHs were characterized for the examined samples: the ash samples were dominated by low-molecular-weight compounds (2-3 rings) while the dust and soot samples exhibited significant proportions of high-molecular-weight PAHs (≧ 4 rings). Our results provide basic information about the occurrence of PAHs in vehicular exhausts (especially gasoline-powered vehicles) and their impacts on environmental contamination levels in a typical developing country as Vietnam. The samples were also screened for potential major organic substances by using GC-MS scan mode, revealing several specific pollutants in each sample type. Based on the analytical results, preliminary discussions about source apportionment and human health risk assessment of organic pollutants were addressed with a focus on PAHs and Me-PAHs. More comprehensive investigations of multiple organic contaminant classes in a wide variety of source-related samples and environmental compartments are needed.

The usage of synthetic fragrances which contained in pharmaceuticals and personal care products (PPCPs) have been increasing in Japan, and environmental discharge of those chemicals have also been increasing. This study tried to detect odor compounds in sediment core samples collected from 1,400 and 9,200 m water depths, in Sagami Bay and Izu-Bonin Trench, Japan. Odor activities in sediment core samples were detected by Gas Chromatography-Olfactometry (GC-O) which detects odor chemicals using human olfaction. It is the first report which analyzed the odor activities in deep-sea sediments. By comparing odor activities found in deeper and surface core samples, six odor compounds were tentatively defined as anthropogenic source. It is required to conduct the novel research topic of "environmental risk assessment for odor compounds". The GC-O could be useful technique to find the emerging chemicals on the research fields of environmental chemistry.

Porous polydimethylsiloxine (PDMS) membranes were prepared using polyethylene glycol (PEG) or propylene glycol (PG) as pore forming agent (PFA). After the PDMS/PFA membranes were prepared, they were immersed in warm water to remove PFA from the membranes to prepare the PDMS porous membranes. Symmetric porous PDMS membrane was obtained when PEG was used as PFA. However, asymmetric porous membrane having a dense PDMS layer on one surface was prepared when PG was used as PFA. The porosity of the membranes increased with PFA content. The solvent permeation across the membranes was measured by low-pressure (0.2 MPa) driven filtration. Three kinds of ink solutions (green, blue and white) containing fine solid particle less than 360 μm and organic solvent were used as feed solutions. The permeation increased with increasing the PFA content. The solid particle weight concentrations in ink solutions were about 10 wt%, however, almost pure solvent was obtained for all the ink solutions by the filtration when the membranes prepared using PG as PFA: the solid particle weight concentration was less than 1 wt% in permeate.

On March 2011, Great East Japan Earthquake, a series of earthquakes struck Tohoku areas and derived about 20,000,000 metric tons of disaster debris (building materials, household appliances, furniture, and wood). To store and process those debris, agricultural fields had been used as emergency debris storage sites. Environmental contamination of agricultural soils by organic and inorganic micropollutants from those debris has been a public concern. To identify chemicals of concern in the soil, our research group used a novel analytical method for comprehensive monitoring of organic and inorganic micropollutants on the emerging situation. An automated identification and quantification system with gas chromatography mass spectrometry (AIQS-GC) was used for detection of organic micropollutants. Total concentrations of elements including Pb, Cd, Se, As, Cu, and Cr in agricultural soil samples collected before and after debris dumping showed 72 and 84 ng g^-1, and those were lower than regulatory standards on environmental soil. On the other hand, concentrations of total organic micropollutants in those samples which were before and after debris dumping showed 330 and 2,300 ng g^-1, respectively. Concentrations of organic micropollutants in the soil after dumping showed higher than those before use.

A simple quantitative analysis method for the detection of potassium in bamboo has been developed. Phyllostachys edulis from Anan City in Tokushima Prefecture was used in this study. In this method of potassium determination, the electrical conductivity of bamboo was measured after ashing and dissolution in pure water. The optimum bamboo ashing time was determined to be 8 h because the effect of water-soluble or exchangeable phosphorus on the electrical conductivity disappeared after bamboo ashing for >8 h and the obtained electrical conductivity was constant. The electrical conductivity and potassium content of various bamboo samples were determined by ICP (Inductively Coupled Plasma) emission spectroscopy and compared. The results showed a significant correlation between them (p<0.01, r²=0.988). Moreover, the results indicated that a good calibration curve was obtained for this method. Therefore, the proposed method can be used for the simple analysis of potassium at the field level without the use of expensive analyzers.

Adsorption of phosphate from aqueous solution has been conducted using calcined scallop shells (CSS), and XRD spectra, TG/DTA signals and pore properties (BET) of CSS were characterized. The influences of calcination temperature of scallop shells, pH, adsorption time and concentration on the phosphate adsorption using CSS were studied in batch adsorption experiment. The XRD spectra showed that CaO appeared after calcination at 800°C, the TG/DTA result exhibited decreasing weight around 38% from 600 to 800°C and BET surface area portrayed increasing value after calcination process at 800°C. The solution pH on the phosphate adsorption had no significant effect by calcination at 800°C (CSS-800). A comparison of kinetic models applied to the adsorption data by CSS-800 was evaluated with pseudo-first order and pseudo-second order model, and the experimental data were fitted well to pseudo-second order kinetic model, while the result of isotherm studies had an approach to Langmuir method with linear regression of 0.998. The adsorption amount of CSS-800 was 30 times higher than scallop shell without calcination.

In this study, we examined a fish survey method using environmental DNA (eDNA) metabarcoding in a river, and the relationship between the fish survey results and water quality detected in eDNA was analyzed. eDNA surveys and fishing surveys were conducted in summer and winter, targeting three sites on three rivers in Fukuoka prefecture. Our comparison of riffles and pools and our examination of the appropriate places to collect eDNA samples revealed that the detected fish species were not completely consistent between the two kinds of surveys and there was no ecological features common to detected fish species. Therefore, sampling at multiple locations is expected to reduce detectable fish dropouts. More fish species were detected in the eDNA survey than in the collection survey at all times. However, the results also suggested that the DNA of fish species living upstream may remain at sampling site, and benthic fish species tend to be difficult to detect by eDNA surveys. In addition, the influence of water quality on the characteristics of the survey site were analyzed, since marine species were detected in some river eDNA surveys. The results suggested that domestic drainage is likely to affect the characteristics in winter, when the amount of water is small, and the change in concentration of linear alkylbenzene sulfonic acid and its salts and the change of the ratio of chloride ions may be used as an index of domestic drainage.

The uranium (U) concentrations of the agricultural and non-agricultural soils in four areas (Isa, Nagashima, Nansatsu, and Osumi) in Kagoshima Prefecture were determined. The U concentrations of the agricultural soils were higher than those of the non-agricultural soils in all areas. The U concentrations were positively correlated with the P concentrations in the soils, which suggested a link between long-term phosphate fertilizer application and U accumulation in the soils. The amounts of U enriched in the agricultural soil surfaces (0-15 cm depth) in the Isa, Nagashima, Nansatsu, and Osumi areas, as calculated from the comparison with the non-agricultural soils, were estimated to be 47-318, 25-343, 61-226, and 47-185 mg/m², respectively. This demonstrated that the accumulation of U occurred in the agricultural soils in these areas. The commercially available superphosphate, magnesium multi-phosphate, fused magnesium phosphate, animal waste composts, and sewage sludge compost in these areas contained 51.6, 22.2, 10.6, 0.88-1.07, and 1.56 μg/g of U, respectively, which showed that these fertilizer materials could become sources of U in agricultural soils. According to the calculation with reference to the amount of fertilizer applied, it was estimated that the amounts of U added from fertilizers were 2.7-3.0 mg/m² in rice paddy fields and 8.6-9.2 mg/m² in Chinese cabbage fields per cropping system. These results indicated that the amounts of U input derived from fertilizers per cropping system differed greatly depending on the cultivated crop.

Regarding Cr (VI) measurement by an iron coprecipitation operation, we found an effluent sample with a low recovery rate. Note 11 of JIS K 0102: 2016 65.2 Cr (VI) has no detailed description of the operation, so we explored an optimal operating conditions using ultrapure water. In addition, since the dominant Cr valence depends on the pH and Eh of the solution, a recovery test was performed using ultrapure water whose pH and Eh were adjusted with sodium sulfite. As the amount of sodium sulfate was added, the pH was increased while Eh was decreased, and the recovery rate of Cr (VI) was decreased, it was confirmed that pH, Eh, and reducing substance are related to the recovery rate of Cr (VI). In the Eh-adjusted sample, it was confirmed that the recovery rate was improved by adding ammonia water before the addition of recovery standard solution. Based on the results of these studies, an effluent sample with a low recovery rate was subjected to aeration to adjust the Eh, and ammonia water was added first so that the pH did not become acidic during the iron coprecipitation operation. The recovery test confirmed that Eh and the recovery rate were increased with the longer aeration duration. Therefore, if the actual sample is reduced condition, an aeration treatment in addition to particle coagulation period, filtration temperature, and reagent addition sequence improves the recovery rate of Cr (VI) and makes it possible to evaluate appropriately.

"What solvent should I use?" This is a question environmental chemical researchers and practitioners often ask themselves in the laboratory. This article presents basic concepts of solvent selection, grounded in understanding of intermolecular interactions between solvent and solute molecules.

The concentrations of butylitn and phenyltin compounds in water, sediment, plankton, mussel and fish samples in the Port of Osaka were monitored for a long time. The characteristics of contamination of organotin compounds in the Port of Osaka were clarified by cluster analysis using the concentrations of butyltin or phenyltin compounds before regulation in Japan. These stations in the Port of Osaka were clarified three groups of 1) marina, 2) the area where many small vessels are sailed and moored with poor flushing, 3) the area where many vessels are sailed. Tributyltin concentrations in most groups are decreasing during monitoring period and especially the trend was drastically in marina. Triphenyltin was not detected in water samples after regulation. The concentrations of TBT and TPT in fish samples were decreasing slowly after regulations and the concentrations of these compounds in fish in 1999 were lower than those acceptable concentration which were calculated from acceptable daily intake (ADI).

Although butyltin concentrations in water samples collected in 2016 from Tanabe Bay were similar to in 2004~2006, TPT concentrations in 2016 were lower than those in 2004~2006. TBT and TPT in sediment samples in 2016 were lower than those in 2004~2006.