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In order to determine recent behaviors in atmospheric polycyclic aromatic hydrocarbon (PAH) concentrations at the west end of Japan and to reveal the causes of these behaviors, atmospheric PAH concentrations were measured in suburban and forest sites of Nagasaki, Japan from 2017 to 2021. The results showed that the total concentration of PAHs decreased considerably by 60% and 57% in suburban and forest sites, respectively, over this period. When analyzed by season, the rate of decrease in winter was markedly high. Therefore, the decreasing behavior in PAH concentrations in Nagasaki in recent years was considered to be mainly due to less PAHs originating from cold continental regions such as northern China. In particular, the reduction in coal and biomass combustion for winter heating in households, the efforts to improve air quality, and the limitation of economic activities in response to COVID-19 were likely responsible for the decrease in atmospheric PAH concentrations. In addition, although the PAH concentrations decreased, there was no significant change in the breakdown of the number of benzene rings in the PAH or in the attributes of their sources., Applied Sciences, 12(21), art. no. 10963; 2022

In order to clarify the level transboundary air pollution caused by polycyclic aromatic hydrocarbons (PAHs) and genotoxic substances, aerosols were collected from forest and suburban sites in Nagasaki, west Japan, for 6 years. The PAH concentration was measured, and the genotoxicity of the substances were evaluated using the umu test. The results showed no notable trends in the concentration or toxicity of either sites throughout the study period. The suburban and forest sites shared similar seasonal fluctuation patterns and quantitative values, suggesting that the western end of Japan might be affected by long-range transported pollutants, especially in winter. PAH concentration and genotoxicity showed the same seasonal patterns of increased levels in winter and lower levels in summer. This suggests that PAHs and genotoxic substances were correlated and share common sources. Back trajectory and source analyses were conducted using the diagnostic ratios of PAHs. It was predicted that air pollution by PAHs at the forest site arise predominantly as a result of biomass or coal combustion in continental regions, such as northern parts of China and the Korean Peninsula. This is particularly expected in winter. Therefore, genotoxic substances would also be strongly influenced by transboundary pollution from the continental region. In addition, it was estimated that the contribution of transboundary PAH pollution could reach 70% at the suburban site in winter., International Journal of Environmental Research and Public Health, 17(4), art.no.1210; 2020

Sediments, mudskippers, and common gobies were collected from the estuaries of nine rivers along the coast of the Ariake Sea in the northwestern part of Kyushu. The sediments were analyzed for alkylphenols, organotin compounds, and polycyclic aromatic hydrocarbons. Then, male mudskippers and common gobies were analyzed for serum vitellogenin concentration. Sediments from the estuary of the Omuta River, which has residential areas in its upper reaches and many large-scale chemical plants in its lower reaches, exhibited higher concentrations of these three types of chemicals than the other rivers, and male mudskippers caught in the Omuta River exhibited higher serum vitellogenin concentrations than mudskippers caught in other rivers. One chemical substance thought to be responsible for these elevated vitellogenin concentrations is nonylphenol, a type of alkylphenol. Male common gobies caught in the Suwa River exhibited higher vitellogenin concentrations than common gobies caught in other rivers. Although the Suwa River had high polycyclic aromatic hydrocarbon concentrations, the elevated vitellogenin concentrations of these male common gobies were thought to be attributable to factors such as sewage treatment plants, not polycyclic aromatic hydrocarbons. However, organotin compounds were detected in all estuarine sediments. This was attributed to the fact that the Ariake Sea is a good area for fishing and a number of small fishing vessels anchor and operate in the estuaries of all these rivers., Nagasaki University Major Research Project: Restoration of Marine Environment and Resources in East Asia, Coastal Environmental and Ecosystem Issues of the East China Sea ,pp.191-204; 2010

Immersion and field surveys were conducted in the northwestern part of Kyushu, to investigate the estrogenic activity in male Japanese common goby. Serum vitellogenin (Vg) concentration and total estrogenic activity in male common goby, based on microanalysis of natural estrogens (E1, E2, E3) and estrogenic compounds (NP, BPA, OP), were measured. The immersion survey in Ariake Sound suggested the possibility of the progress of environmental estrogen pollution. Field surveys in Ohmura Bay and Ariake Sound also detected estrogenic activity. An extremely high ratio of Vg-positive males were recorded in Ohmuta River Estuary, and total estrogenic activity in environmental water in this site were also higher than that recorded in other sites. The main causative substance of the estrogenic activity was not alkylphenols, but natural estrogens (E2), probably due to a high population density and a low sewage diffusion rate., Nagasaki University Major Research Project: Restoration of Marine Environment and Resources in East Asia, Coastal Environmental and Ecosystem Issues of the East China Sea ,pp.205-213; 2010

Seasonal and diurnal fluctuations in pharmaceuticals and personal care products (PPCPs) concentrations in residential sewage water were ascertained in an area with no businesses industry (e.g., plants or offices) upstream. PPCPs with high detection rates included ibuprofen, acetaminophen and indomethacin (antipyretic analgesics), atenolol and disopyramide (antiarrhythmics), clarithromycin (antibiotic), levofloxacin (synthetic antimicrobial agent) and triclosan (disinfectant). In summer, the concentration of triclosan was the highest, while in winter, the concentrations of ibuprofen and acetaminophen were higher than the others. Moreover, three types of diurnal fluctuations were observed: no marked diurnal changes (triclosan), high daytime concentrations (disopyramide) and high nighttime concentrations (acetaminophen)., Journal of Health Science, 54(2), pp.240-243; 2008

Little information on the evaluation of airborne particulate matter (APM) and sedimentation particles from subway stations is available. The thermal metamorphism of train wheels generating toxic particles in subway stations is a possibility. In this study, the toxicity and physiological effects of particles from subway stations were evaluated using a yeast bioassay system. Estrogenic and antiestrogenic activities of APM in APM extracts from subway stations were determined. No estrogenic activity was found in the APM fractions and their S9-activated APM samples. Sedimentation dust samples also showed no estrogen activity. In contrast, extracts from sedimentation dust samples showed antiestrogen activity. Marked yeast toxicity was observed in the samples extracted from sedimentation dust. Potent yeast toxicity was also found in the S9-activated extracts from sedimentation dust. The results suggest that sedimentation dust from a semiclosed area of a subway system has antiestrogen activity, although both the origin and generation system of this activity are uncertain. These pollutants in sedimentation dust may change to a more toxic form in vivo by S9 activation., Environmental sciences, 14(4), pp.203-210; 2007

Synthetic musk fragrance compounds, such as polycyclic musks (PCMs), are a group of chemicals used extensively as personal care products, and can be found in the environment and the human body. PCMs, such as 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexa-methylcyclopenta-gamma-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyltetralin (AHTN), are known to have agonistic activities toward human estrogen receptor alpha (hERalpha) and hERbeta, and have antagonistic activity toward the human androgen receptor (hAR), as shown in several reporter gene assays. However, little is known about the interaction of PCMs with the human thyroid hormone receptor (hTR), and the hormonal effects of other PCMs except for HHCB and AHTN. In this study, we focus on the interactions of six PCMs, namely, HHCB, AHTN, 4-acetyl-1,1-dimethyl-6-tert-butyl-indan (ADBI), 6-acetyl-1,1,2,3,3,5-hexamethylindan (AHMI), 6,7-dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanone (DPMI), and 5-acetyl-1,1,2,6-tetramethyl-3-isopropy-lindan (ATII) with hERalpha, hAR, and hTRbeta by in vitro reporter gene assay using Chinese hamster ovary cells. All the samples were found to be agonists toward hERalpha, whereas no agonistic activities of these PCMs for hAR and hTRbeta were observed. No antagonistic activities for hERalpha and hTRbeta were observed at the concentrations tested. However, several PCMs, namely, HHCB, AHTN, ATII, ADBI, and AHMI, showed dose-dependent antagonistic activities for hAR, and the IC50 values of these compounds were estimated to be 1.0 x 10(-7), 1.5 x 10(-7), 1.4 x 10(-7), 9.8 x 10(-6), and 1.4 x 10(-7) M, respectively. The results suggest that these PCMs interact with hERalpha and hAR but have no hormonal effect on hTRbeta. This is the first report on the agonistic and antagonistic activities of ATII, ADBI, AHMI, and DPMI for hERalpha and hAR as determined by in vitro reporter gene assay using stably transfected Chinese hamster ovary cells., Environmental sciences, 14(4), pp.195-202; 2007

After adding the silylating agents N, O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) or N-methyl-N-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA) to the indirubin solution and leaving for 1 hr at 60°C, the color remained red. Indirubin could be measured by GC/MS after replacing the active hydrogen on the amino group with -Si(CH3)3 or -Si(CH3)2C2H5 groups. However, peak tailing was observed and the quantitative and detection limits were not sensitive enough for practical use. Indirubin silylated at four sites was observed under the reaction conditions as follows; solvent dichloromethane: acetone (8 : 2), 90°C reaction temperature, 1 hr reaction time, BSTFA derivative, pyridine catalyst. The color of the solution changed from red to colorless. Retention time appeared to be faster and the peak shape improved. Under these conditions, the quantitative and detection limits of indirubin were 5 ppb and 0.1 ppb, respectively., Journal of Health Science v.49(1) p.88-90, 2003

We describe a novel approach to evaluating the respiratory toxicity of chemicals in the free-living nematode Caenorhabditis elegans. Using DOX-96KT, a general purpose, multi-channel dissolved oxygen (DO) measuring system, we measured the DO concentration in culture media containing C. elegans exposed to chemicals to assay for respiratory toxicity. The current value, which is an index of the dissolved oxygen concentration in culture media, was measured every 10 sec for 30 min at 24°C. We focused on the respiration levels of the exposed worms between 500 and 1800 sec. This method produces results that are similar to the computer tracking system measuring behavioral toxicity. Since it can do multiple dilution series tests at a given time, it is useful for concentration-activity correlation studies. This novel technique is not only an alternative to the computer tracking system for measuring behavioral toxicity but also a rapid sublethal toxicity test for chemical hazard assessment., Journal of Health Science v.48(3) p.269-272, 2002

Nine different food cans, packed with water, were heat-treated for 30 min at 80 or 100°C in order to elucidate the trends associated with the leaching of bisphenol A (BPA) from internal coatings. Low levels of BPA were detected in water from all unheated cans, rising to 0.06 to 32 ng/cm2 after heating at 100°C. Reducing the heat-treatment temperature to 80°C was found to reduce the BPA concentration in the contained water by up to two-thirds. The cans that recorded the highest BPA concentrations in water after heating were found to have components (lid, bottom or body) with high available BPA contents., Journal of Health Science v.48(4) p.331-334, 2002

The material balance of phosphorus in a semi-closed bay (Omura bay) has been calculated by actuality measurements and data from an observation satellite (LANDSAT 5) over the last eleven years. It appeared that the phosphorus inflows to the bay from the 696 places of business and the twelve rivers were 293 tons/year and 20 tons/year, respectively. About 90% of the phosphorus from the places of business was released into the bay from only six sewage treatment plants. The phosphorus outflows from the bay, which occurred with the tide changes and with the catching of fish, were 219 tons/year and 7 tons/year, respectively. The urban areas inside the watershed that were calculated from the LANDSAT data using the normalized difference vegetation index (NDVI) value showed an increase each year with a wide range of variation. This slope was closer to the one showing the increasing amount of phosphorus in the bay than to the slope of the increase in population inside the watershed., Journal of Health Science v.47(2) p.155-161, 2001