Direct observation of microcirculatory parameters in rat brain after local exposure to radio-frequency electromagnetic field

A cranial window method modified for our experiment enabled to observe the cerebral microcirculation including the blood-brain barrier permeability after a local expose to radio-frequency electromagnetic fields with a monopole antenna in rats. The present report reviews our recent publications that reported no noticeable changes in the cerebral microcirculatory parameters due to RF-EMF exposure.     

Petrogenetic characteristics of molten slag from the pyrolysis/melting treatment of MSW

MSW slag materials derived from four pyrolysis melting plants in Japan were studied from the viewpoint of petrology in order to discriminate the glass and mineral phases and to propose a petrogenetic model for the formation process of molten slag. Slag material is composed of two major components: melt and refractory products. The melt products that formed during the melting process comprise silicate glass, and a suite of minerals as major constituents. The silicate glass is essentially composed of low and high silica glass members (typically 30% and 50% of SiO(2), respectively), from which minerals such as spinels, melilite, pseudowollastonite, and metallic inclusions have been precipitated. The refractory products consist mainly of pieces of metals, minerals and lithic fragments that survived through the melting process. Investigations demonstrated that the low silica melts (higher Ca and Al contents) were produced at upper levels of high temperature combustion chamber HTCC, at narrower temperature ranges (1250-1350 degrees C), while the high silica melts formed at broader temperature ranges (1250-1450 degrees C), at the lower levels of HTCC. The recent temperature ranges were estimated by using CaOAl(2)O(3)SiO(2) (CAS) ternary liquidus diagram that are reasonably consistent with those reported for a typical combustor. It was also understood that the samples with a higher CaO/SiO(2) ratio (>0.74-0.75) have undergone improved melting, incipient crystallization of minerals, and extensive homogenization. The combined mineralogical and geochemical examinations provided evidence to accept the concept of stepwise generation of different melt phases within the HTCC. The petrogenesis of the melt products may therefore be described as a two-phase melt system with immiscible characteristics that have been successively generated during the melting process of MSW.     

Detection of benzotriazole UV stabilizers in the blubber of marine mammals by gas chromatography-high resolution mass spectrometry (GC-HRMS)

Benzotriazole UV stabilizers (BUVSs), such as UV-328 and UV-327, were identified in the blubbers of finless porpoises (Neophocaena phocaenoides) collected from the Ariake Sea, western Japan, by gas chromatography-high resolution mass spectrometry (GC-HRMS). The mean concentrations and standard deviations of UV-328 and UV-327 in five blubber samples were 38 ± 28 ng g(-1) (lipid wt) and 19 ± 19 ng g(-1), respectively. The bioconcentration factor (BCF) of UV-327 between water and finless porpoises was estimated to be 33?300, which is approximately one order of magnitude higher than that found for small fish inhabiting the same regions. The BCF of UV-327 in finless porpoises was similar to that of persistent organochlorine pesticide, hexachlorocyclohexane (HCH: 37?000) in marine mammals from the western North Pacific Ocean. These results suggest that BUVSs appear to be persistent and bioaccumulative in the aquatic food chain. Further investigations on temporal trends, and regional and global monitoring of BUVSs are needed to understand their environmental profiles and potential risks to wildlife and human.     

Fluorophotometric Determination of Trace Amounts of Atmospheric Ozone

This work was initiated in an effort to obtain a better method for the manual determination of trace amounts of atmospheric ozone. The method described depends upon the fact that ozone oxidizes nonfluorescent 9, 10-dihydroacridine to fluorescent acridine. When the ethyl alcohol solution of acridine is acidified by 6N acetic acid, the fluorescence maximum occurs approximately at 482 mμ and its intensity is sufficiently strong to be useful in this analysis. Linear relationships between acridine concentrations and fluorescence intensities were obtained from 0.1 to 3.5 μg per ml. by measurement with a commercial fluorophotometer. The results indicated that the low concentrations of experimentally prepared ozone measured by this method were in good agreement with those obtained by the phenolphthalin method. This method appeared to be about twice as sensitive as the phenolphthalin method, but it is subject to some interference from nitrogen dioxide.     

A global transport model of lead in the atmosphere

A global atmospheric transport model is used to calculate lead concentrations in the atmosphere. The model performance is evaluated through comparisons with observations in Europe. The model results of lead concentrations in surface air were compared with measurements in East Asia. The detailed comparisons showed generally good agreement for recent decades, although systematic underestimation was found in China. Anthropogenic lead emissions in China are estimated from economic statistics to be 56 000 t yr^?1, which is not small considering the economic scale of China. The underestimations suggest a hidden source of lead emissions. The emissions in Japan and Korea are derived from optimization by the model. The magnitude is about 2000 t yr^?1, which is much greater than that reported by the Pollutant Release and Transfer Register in Japan and Toxics Release Inventory in Korea.     

Online measurements of low-volatile organic chlorine for dioxin monitoring at municipal waste incinerators

In this study, an automatic sampling device and an analysis device have been developed for the measurement of low-volatile organic chlorine (LVOCl) in flue gas. The concentrations of dioxins (polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls) have been estimated by online measurements of LVOCl at a municipal solid waste incinerator (MSWI) using these devices. The LVOCl concentration at the outlet of the selective catalyst reactor (SCR) of the MSWI increased momentarily up to 95 μg Cl m⁻³ during the startup period of the MSWI; subsequently, it gradually decreased to less than 1.0 μg Cl m⁻³ after 50 h from the start of waste feeding. The concentration of toxic equivalent quantity (TEQ)-Dioxins at the SCR outlet had a linear positive relationship with the LVOCl concentrations. Moreover, the level of TEQ-Dioxins concentration can be estimated by using this relationship with LVOCl. From our results, since the LVOCl concentrations in a flue gas can thus be automatically analyzed every hour by online measurements, the operators of an MSWI would be able to monitor approximate TEQ-Dioxin emissions on a daily basis.     

Comparative study of microbial dechlorination of chlorinated ethenes in an aquifer and a clayey aquitard

In order to determine whether natural attenuation of chlorinated ethenes by microbial activity occurs in aquitards, sediments at a site contaminated with tetrachloroethene were vertically studied by drilling. The distribution of microbes (Dehalococcoides group and anaerobic hydrogen producers) and the ability of the sediments to sustain microbial dechlorination were determined in an aquitard as well as in an aquifer. Close-spaced sampling revealed the existence of large populations of Dehalococcoides and H(2)-producing bacteria, especially in the organic-rich clayey aquitard rather than in the aquifer. The vinyl chloride reductase gene was also detected in the clay layer. Furthermore, incubation experiments indicated that the clay sediment could sustain transformations of tetrachloroethene at least to vinyl chloride. In contrast, no significant transformation was observed in the aquifer sand. Our results indicate that dechlorination of tetrachloroethene by bacteria can take place in an organic-rich clayey aquitard, and that organic-rich clay may also be important in the natural attenuation in an adjacent aquifer, possibly supplying a carbon source or an electron donor.     

Dissolution of polystyrene into cyclic monoterpenes present in tree essential oils

We examined dissolution of polystyrene (PS) into cyclic monoterpenes present in tree essential oils, in order to develop an environmentally friendly shrinking agent for expanded polystyrene. The relationship between the chemical structure of the monoterpenes and their dissolution power for PS was studied through the solubility parameter (δ) and apparent activation energy (E _a) for dissolution. (R)-Limonene and its structural isomers on a C=C bond have high solvent power for PS. This favorable solubility was explained by their solubility parameters. The occurrence of hydroxyl group in a solvent molecule, such as in terpinen-4-ol, reduced affinity for PS. Bicyclic monoterpenes and 1,8-cineole, which have sterically bulky structure, showed limited dissolution power even though they have solubility parameters similar to that of (R)-limonene. Their bulky structures would interfere with permeation of solvent into the PS matrix. Cyclic monoterpenes and PS were recovered almost quantitatively by simple steam distillation of the PS solution.     

Nervous system disruption and concomitant behavioral abnormality in early hatched pufferfish larvae exposed to heavy oil

BACKGROUND AND OBJECTIVE: Spills of heavy oil (HO) over the oceans have been proven to have an adverse effect on marine life. It has been hypothesized that exposure of early larvae of sinking eggs to HO leads largely to normal morphology, whereas abnormal organization of the developing neural scaffold is likely to be found. HO-induced disruption of the nervous system, which controls animal behavior, may in turn cause abnormalities in the swimming behavior of hatched larvae. To clarify the toxicological effects of HO, we performed exposure experiments and morphological and behavioral analyses in pufferfish (Takifugu rubripes) larvae. EXPERIMENTAL PROCEDURE: Fertilized eggs of pufferfish were exposed to 50?mg/L of HO for 8?days and transferred to fresh seawater before hatching. The hatched larvae were observed for their swimming behavior, morphological appearance, and construction of muscles and nervous system. RESULTS AND DISCUSSION: In HO-exposed larvae, we did not detect any anomaly of body morphology. However, they showed an abnormal swimming pattern and disorganized midbrain, a higher center controlling movement. Our results suggest that HO-exposed fishes suffer developmental disorder of the brain that triggers an abnormal swimming behavior and that HO may be selectively toxic to the brain and cause physical disability throughout the life span of these fishes.     

Immunologic effects of perinatal exposure to dioxins, PCBs and organochlorine pesticides in Japanese infants

Effects of perinatal exposure to dioxins, PCBs and organochlorine pesticides on lymphocyte subsets were investigated in the peripheral blood from 101 Japanese infants with approximately 10 months of age. Perinatal exposure to these organochlorine compounds were estimated by their contamination levels in the breast milk of the mothers. Lymphocyte subsets such as CD16+, HLA-DR+, CD4+, CD4+8+, CD8+, CD3+ and CD20+ cells in peripheral venous blood were assessed in a subgroup of 92 infants. Greater exposures to HCE, chlordane and dioxins were significantly associated with the increase in the percentages of CD8+ and CD3+ T lymphocytes and CD4+/CD8+ T cell ratios, respectively. In addition, higher HCH exposure was also associated with a decrease in the percentage of HLA-DR+ T lymphocytes. Furthermore effects of dioxins, DDT and PCBs on the percentage of CD16+ T lymphocyte were more pronounced by the combined exposure of dioxins and PCBs or by the combined exposure of DDT and PCBs. Effects of HCE on the percentages of CD8+ T lymphocyte were also more pronounced by the combined exposure of HCE and chlordane. In conclusion, our study suggests that greater exposures to dioxins, PCBs and organochlorine pesticides determined in this study (except dieldrin) influence the immune system of Japanese infant, although the clinical significance of these changes is uncertain.