Tracing the sources of gaseous components (<Superscript>222</Superscript>Rn,CO<Subscript>2</Subscript> and its carbon isotopes) in soil air under a cool-deciduous stand in Sapporo,Japan

Radon (²²²Rn) and carbon dioxide were monitored simultaneously in soil air under a cool-temperate deciduous stand on the campus of Hokkaido University, Sapporo, Japan. Both ²²²Rn and CO₂ concentrations in soil air varied with atmospheric (soil) temperature in three seasons, except for winter when the temperature in soil air remained constant at 2–3°C at depth of 80 cm. In winter, the gaseous components were influenced by low-pressure region passing through the observation site when the ground surface was covered with snow of ~1 m thickness. Carbon isotopic analyses of CO₂ suggested that CO₂ in soil air may result from mixing of atmospheric air and soil components of different origins, i.e. CO₂ from contemporary soil organic matter and old carbon from deeper source, to varying degrees, depending on seasonal meteorological and thus biological conditions.     

Mitochondrial DNA phylogeography of the harbour porpoise Phocoena phocoena in the North Pacific

Genetic structure and phylogeography of the harbour porpoise Phocoena phocoena in the North Pacific were examined using 358 bps sequences from the 5′ end of the mitochondrial DNA control region including those reported previously and newly obtained from the west Pacific. AMOVA and pairwise population φ _st estimates clearly revealed genetic differentiation between an east/south and a north/northwest group with the break along the Pacific Rim at British Columbia. In addition, nested clade phylogeographical analysis, neutrality tests, mismatch distribution analysis, genetic diversities and Mantel test, suggested that the observed genetic structure might have been influenced by contiguous range expansion with restricted gene flow in the direction from south to north along the North American coasts and east to west along the Pacific Rim in the middle to late Pleistocene.     

Classification of the sugarcane residues and their characteristics—an environmental assessment of mortar with addition of sugarcane residues

Journal of Material Cycles and Waste Management - The use of agro-residue in resource-limited regions can be a smart way for civil construction to reduce costs, reduce emissions of pollutant gases...     

Silver speciation in liver of marine mammals by synchrotron X-ray absorption fine structure and X-ray fluorescence spectroscopies

The chemical form of Ag in the livers of five species of marine mammals was examined using X-ray absorption fine structure (XAFS) and X-ray fluorescence (XRF) spectroscopies. The XAFS analysis suggested that Ag(2)Se was present in the livers of the Franciscana dolphin (Pontoporia blainvillei), Dall's porpoise (Phocoenoides dalli), and Baird's beaked whale (Berardius bairdii), whereas Ag(2)S was present in the livers of the striped dolphin (Stenella coeruleoalba) and pygmy killer whale (Feresa attenuata). XRF spectroscopy results revealed that the distribution patterns of Ag and Se in a thin section of the liver of the Franciscana dolphin were the same; this also implied that Ag was associated with Se in the liver. Thus, the interaction of Ag with Se or S may offer significant protection against the toxicity of Ag in marine mammals. The formation of either Ag(2)Se or Ag(2)S might depend on the Hg levels in the liver. Ag(2)Se was observed in liver samples with relatively high Ag/Hg ratio, whereas liver samples with low Ag/Hg ratio contained Ag(2)S.     

Lead contamination in surface soil on roads from used lead–acid battery recycling in Dong Mai,Northern Vietnam

Used lead–acid battery (ULAB) recycling has caused numerous health and environmental issues in developing countries. Surface soil pollution from ULAB recycling activities has been linked with elevated levels of lead in human blood. We measured surface soil lead in and surrounding the ULAB recycling village of Hung Yen in northern Vietnam in 2011, 2013, and 2014. The data were analyzed statistically and discussed with respect to distance from the contamination source, year of measurement, contamination pathway, and countermeasures against the contamination. Transportation routes from the smelter or collection site displayed the greatest concentration of surface soil lead (median 6400–10,000 mg/kg). Surface soil lead decreased significantly with distance along the road from the ULAB recycling site, although such a decrease was not observed for rice fields, agricultural roads, or garden soil. Re-suspension and adherence by traffic were identified as key pollution pathways. Distance from the source, covering of the surface of roads, construction of walls, and position relative to the source were shown to be the most effective factors in the reduction of surface soil lead pollution. Application of a combination of these measures should result in improvement in the health of residents.     

Modelling the Effects of Inflow Parameters on Lake Water Quality

A one-dimensional lake water quality model which includes water temperature, phytoplankton, phosphorus as phosphate, nitrogen as ammonia, nitrogen as nitrate and dissolved oxygen concentrations, previously calibrated for Lake Calhoun (USA) is applied to Uokiri Lake (Japan) for the year 1994. The model simulated phytoplankton and nutrient concentrations in the lake from July to November. Most of the water quality parameters are found to be the same as for Lake Calhoun. To predict probable lake water quality deterioration from algal blooming due to increased nutrient influx from river inflow, the model was run for several inflow water conditions. Effects of inflow nutrient concentration, inflow volume, inflow water temperatures are presented separately. The effect of each factor is considered in isolation although in reality more than one factor can change simultaneously. From the results it is clear that inflow nutrient concentration, inflow volume and inflow water temperature show very regular and reasonable impacts on lake water quality.     

Temporal variation of Cs and Pu in the sea of Japan

Concentrations of the anthropogenic ¹³⁷Cs and ^239,240Pu in surface water of the Sea of Japan were in the ranges of 2·7–3·8 mBq l^-1 and 1·3–8·0 μBq l^-1, respectively, in 1993–1994, which are in the same order of magnitude as those in the North Pacific. The time-series data indicated a marked increase of surface ¹³⁷Cs in 1986 and 1987 after the major radioactive dumping and the Chernobyl fallout in 1986 and then rapidly decreased thereafter. The apparent half-residence time of ¹³⁷Cs in the surface water was estimated to be about 3 years for excess ¹³⁷Cs and 16 years for a rather long time-scale transport, respectively. For ^239,240Pu in the surface water, no systematic temporal variation was observed over the past two decades, which may reflect rapid recycling of deeper Pu. The results revealed that most of the recent radioactivity in water columns of the Sea of Japan was of global fallout origin from atmospheric nuclear testing and partly the Chernobyl fallout. No clear signal about the effect of radioactivity from Russian dumping was observed.     

Growth and grazing rates of the tintinnid ciliate<Emphasis Type="Italic"> Favella taraikaensis</Emphasis> on the toxic dinoflagellate<Emphasis Type="Italic"> Alexandrium tamarense</Emphasis>

Growth and feeding activities of the tintinnid ciliate Favella taraikaensis fed the toxic dinoflagellate Alexandrium tamarense were examined in laboratory experiments. Both growth and ingestion rates of F. taraikaensis as a function of the A. tamarense concentration were fitted to a rectangular hyperbolic equation. The maximum growth and ingestion rates of F. taraikaensis were 1.0 day^–1 and 2.8 cells ind. h^–1 (carbon specific ingestion rates: 3.5 day^–1), respectively, which are both included in the range of previous data reported for Favella spp. feeding on other algae. The gross growth efficiency (GGE) of F. taraikaensis ranged from 0.26 to 0.49 (mean value 0.40) at the concentration of 10–800 cells ml^–1, which is within the range of previous data on Favella spp. Also, the growth and ingestion rates and GGE of F. taraikaensis on A. tamarense were not significantly different from the values on another non-toxic dinoflagellate (Heterocapsa triquetra) at two different prey concentrations. This indicates that the toxicity of A. tamarense probably did not influence the feeding and growth activities of F. taraikaensis at concentrations of less than ca. 800 cells ml^–1. To evaluate the grazing by F. taraikaensis on A. tamarense blooms in the field, the population dynamics of A. tamarense were simulated based on the growth and ingestion parameters of F. taraikaensis. As a result, the grazing impact by F. taraikaensis was considered to potentially regulate the development of A. tamarense blooms. If the toxicity of A. tamarense does not influence the growth and feeding activities of F. taraikaensis, the occurrence of such grazer plankton are considered to be important for predicting the course of A. tamarense bloom dynamics under natural conditions.Communicated by T. Ikeda, Hakodate     

Inactivation of antineoplastics in clinical wastewater by electrolysis

Wastewater from clinical institutions contains a considerable amount of toxic substances. Among the toxic substances, antineoplastics may induce carcinogenesis, teratogenesis, and the emergence of mutant microorganisms in the environment. Although the incineration or chemical treatments of disposed antineoplastics are recommended, a high energy during incineration and a careful quality control during chemical treatment are required. In this study, we determined the conditions for the electrolytic treatment of an antineoplastic, epirubicin hydrochloride (EH), using two platinum electrodes with a constant current of 100 mA. We analyzed the cytotoxicity, mutagenicity and antibacterial activity of electrolyzed EH and compared them with those of unelectrolyzed EH. Nearly 100% cytotoxicity, mutagenicity and antibacterial activity were eliminated and HPLC did not detect an EH molecule, in the case of electrolysis for 6 h. We also examined the biological cytotoxicities of electrolyzed irinotecan hydrochloride, vincristine sulfate, mitomycin C, paclitaxel, methotrexate and cisplatin, and found that 72.1-99.999% toxicity was eliminated by electrolysis under the same conditions. The biological toxicity of a mixture of these drugs was determined to be decreased by approximately 99% by electrolysis under the same conditions.