Comparison of the Concentration of Suspended Particles and Their Chemical Composition near the Ground Surface and Dust Extinction Coefficient by LIDAR.

In many epidemiological studies, the dust extinction coefficient measured by light detection and ranging (LIDAR) is used as an indicator of exposure to Asian dust. However, few reports on the relationship between the distribution of total suspended particles (TSPs) near the ground surface and the dust extinction coefficient exist. In this study, we examined the relationship between the concentrations of TSPs near the ground surface, substances indicative of mineral content, and air pollutants that may be transported with Asian dust and dust extinction coefficients in two regions: Imizu and Yurihama-Matsue, from March to May in 2011 and 2013.

Hexabromocyclododecane in riverine and estuarine sediments from Osaka, Japan: spatial distribution and concentration variability within identical samples.

In this study, hexabromocyclododecane (HBCD) in riverine and estuarine sediments was investigated in Osaka, Japan. The mean total HBCD concentration detected in sediments ranged from < 0.50 to 130 ng g dry weight.

Comparison of Air Pollution in Metropolises in China (Beijing) and Japan (Osaka and Nagoya) on the Basis of the Levels of Contaminants and Mutagenicity.

Public concern regarding the transport of air pollutants from mainland East Asia to the leeward area by the prevailing westerlies in spring and winter monsoon has been growing in recent years. We collected total suspended particle (TSP) in Beijing, a metropolis of China located windward of Japan, in spring (late February 2011-May 2011) and in winter (November 2012-early February 2013), then analyzed metals, ions, and organic compounds and mutagenicity, and compared the pollution levels with samples collected at two Japanese metropolises (Osaka and Nagoya) during the same periods. The medians of concentration of TSP and other factors in Beijing were much larger than those in the Japanese metropolises.

Spatial correlativity of atmospheric particulate components simultaneously collected in Japan.

The simultaneous sampling of total suspended particles was performed at 14 sites in Japan during July 2008-June 2009. The spatial correlativity of each particulate composition toward Osaka was obtained for nine selected sites to overview the chemical composition and geographical distribution of particulate components across a wide range of areas nationwide. The spatial correlatives of atmospheric particulate components were extended to an even wider range of areas up to 950 km distance (meso-alpha scale region, >200 km) for a far-reaching distance analysis unique in the literature.

Seasonal Fluctuations in Air Pollution in Dazaifu, Japan, and Effect of Long-Range Transport from Mainland East Asia.

To clarify the seasonal fluctuations in air pollution and the effect of long-range transport, we collected airborne particles (n=118) at Dazaifu in Fukuoka, Japan, from June 2012 to May 2013 and measured Pb and SO4(2-), which are indicators of the long-range transport of anthropogenic air pollutants, as well as their mutagenicity, and other factors. The levels of airborne particles, Pb, and SO4(2-) were very high on March 4, 8, 9, and 19, and May 13, 21, and 22, 2013. The backward trajectories indicated that air masses had arrived from the Gobi Desert and northern China on those days.

Long-range transport of mutagens and other air pollutants from mainland East Asia to western Japan.

Introduction: Asian dust events, transport of dust particles from arid and semi-arid areas in China and Mongolia to the east by prevailing westerlies, are often observed in Japan in spring. In recent decades, consumption of fossil fuels has markedly increased in mainland East Asia with rapid economic growth, and severe air pollution has occurred. A part of air pollutants including mutagens, such as polycyclic aromatic hydrocarbons (PAHs), generated in mainland East Asia are thought to be transported to Japan by the prevailing westerlies, like Asian dust, and winter monsoon.

Development of a novel evaluation method for air particles using surface plasmon resonance spectroscopy analysis.

The aim of this study was to develop a novel evaluation method for air particles using surface plasmon resonance spectroscopy (SPR) analysis. An L1 sensor chip modified with immobilized liposome was used as a model of the membrane of epithelial cells in organs of respiration. A test suspension of dispersed air particles was flowed onto the sensor chip.

Genotoxicity and metabolism of the source-water contaminant 1,1-dichloropropene: activation by GSTT1-1 and structure-activity considerations.

1,1-Dichloropropene (1,1-DCPe) is a contaminant of some source waters used to make drinking water. Because of this and the fact that no toxicological data were available for this compound, which is structurally similar to the rodent carcinogen 1,3-dichloropropene (1,3-DCPe), 1,1-DCPe was placed on the Contaminant Candidate List of the US Environmental Protection Agency. Consequently, we have performed a hazard characterization of 1,1-DCPe by evaluating its mutagenicity in the Salmonella assay and its DNA damaging (comet assay) and apoptotic (caspase assay) activities in human lymphoblastoid cells.

Do arsenosugars pose a risk to human health? The comparative toxicities of a trivalent and pentavalent arsenosugar.

Seafood frequently contains high concentrations of arsenic (approximately 10-100 mg/kg dry weight). In marine algae (seaweed), this arsenic occurs predominantly as ribose derivatives known collectively as arsenosugars. Although it is clear that arsenosugars are not acutely toxic, there is a possibility of arsenosugars having slight chronic toxicity.

Use of a high-throughput umu-microplate test system for rapid detection of genotoxicity produced by mutagenic carcinogens and airborne particulate matter.

In the present study, we developed a rapid umu-microplate test system that uses the nitroreductase- and O-acetyltransferase-overproducing Salmonella typhimurium strain NM3009 and the O-acetyltransferase-overproducing S. typhimurium strain NM2009 to detect genotoxic activity in small volume samples. The assay was used to test the genotoxicity of several standard mutagens and environmental samples.

Methylated trivalent arsenicals as candidate ultimate genotoxic forms of arsenic: induction of chromosomal mutations but not gene mutations.

Arsenic is a prevalent human carcinogen whose mutagenicity has not been characterized fully. Exposure to either form of inorganic arsenic, As(III) or As(V), can result in the formation of at least four organic metabolites: monomethylarsonic acid, monomethylarsonous acid (MMA(III)), dimethylarsinic acid, and dimethylarsinous acid (DMA(III)). The methylated trivalent species, as well as some of the other species, have not been evaluated previously for the induction of chromosome aberrations, sister chromatid exchanges (SCE), or toxicity in cultured human peripheral blood lymphocytes; for mutagenicity in L5178Y/Tk(+/-) mouse lymphoma cells or in the Salmonella reversion assay; or for prophage-induction in Escherichia coli.

Removal of heavy metals in rinsing wastewater from plating factory by adsorption with economical viable materials.

The removal of heavy metals from plating factory wastewater with economical materials was investigated by the column method. Montmorillonite, kaolin, tobermorite, magnetite, silica gel and alumina were used as the economical adsorbents to wastewater containing Cd(II), Cr(VI), Cu(II) and Pb(II). This removal method of heavy metals proved highly effective as removal efficiency tended to increase with increasing pH and decrease with increasing metal concentration.

Removal of organic polyelectrolytes and their metal complexes by adsorption onto xonotlite.

Natural organic polyelectrolytes (humic and fulvic acids) and their metal complexes were removed by adsorption onto xonotlite. The removal percentages of humic and fulvic acids by xonotlite were approximately 80% and 30%, respectively. Humic acid removal from solution by adsorption onto xonotlite took place more readily than fulvic acid removal.

Detection of genotoxicity of atmospheric particles using a high-throughput microplate umu-test system.

A previously developed and highly sensitive umu-microplate test system based on the nitroreductase- and O-acetyltransferase-overproducing strain Salmonella typhimurium NM3009 and the O-acetyltransferase-overproducing strain S. typhimurium NM2009 was applied to the detection of genotoxic activity in atmospheric particles in urban areas using a relatively small sample load. The results showed that the test system was able to detect slight increases in induced genotoxicity in atmospheric particles and that genotoxicity was detected mainly in the fine fraction but also partially in the coarse fraction.