Respiratory tract retention of inhaled air pollutants: Report 1 : Mercury absorption by inhaling through the nose and expiring through the mouth at various concentrations

To study atmospheric mercury absorption in human respiratory passage-ways, mercury in expired air was measured in three different states of breathing: steady breathing, deep breathing and breath held after inspiration.In this study, air containing mercury was inhaled through the nose and expired through the mouth. The concentration of mercury in the exhaled air was determined by the technique of gold-amalgam trapping, heat vaporization, and flameless atomic absorption measurement.The subjects were 13 male adults, aged 25–62 years, and 38 cases were observed. Four different concentrations of mercury, 1–3, 4–6, 10–11, and 20–30 μg/m³ were used, and absorption for each was determined. When the concentration was 1–3 μg/m₃, the absorption was 74–92%, the average being 82.5%. At concentrations of 4–6, 10–11, and 20–30 μg/m₃, the absorption was 76.6–100%, 75.5–99.2%, and 79.9–95.9% respectively, and the average was 88.8%, 85.2%, and 87.7% respectively.A slightly higher rate of mercury absorption was observed in deep breathing than in steady breathing, and when expiration was suppressed for some time after inspiration, the rate increased remarkably to 97.4–99.7%. Prolonged retention of inhaled air containing mercury in the respiratory tract is believed to have caused the increased absorption.     

Dechlorination of polychlorinated dibenzo-p-dioxins catalyzed by noble metal catalysts under mild conditions

Dechlorination of polychlorinated dibenzo-p-dioxins such as 2,7-dichlorodibenzo-p-dioxin (2,7-DCDD) and 1,2,6,7-tetrachlorodibenzo-p-dioxin (1,2,6,7-TCDD) was carried out in a solution of NaOH in 2-propanol in the presence of carbon-supported noble metal catalyst (Pd/C or Rh-Pt/C) at temperatures between 23 and 35 degrees C. At initial concentrations of 140-240 micrograms/ml, 2,7-DCDD and 1,2,6,7-TCDD were efficiently converted to a chlorine-free product, dibenzo-p-dioxin (DD), in high yield (60-80%). The conversion of 2,7-DCDD and 1,2,6,7-TCDD and the yield of DD were hardly affected by the atmosphere (N2 or air). We postulate that the displacement of aromatic chlorines by hydrogen selectively occurs on the catalyst, involving hydrogen-transfer from 2-propanol to the substrates.     

Glycosylation of bisphenol A by freshwater microalgae

The endocrine disruptor bisphenol A (BPA, 4,4'-isopropylidenediphenol) is used to manufacture polycarbonate plastic and epoxy resin linings of food and beverage cans, and the residues from these products are then sometimes discharged into rivers and lakes in waste leachates. However, the fate of BPA in the environment has not yet been thoroughly elucidated. Considering the effect of BPA on aquatic organisms, it is important that we estimate the concentration of BPA and its metabolites in the aquatic environment, but there are few data on the metabolites of BPA. Here, we focused on freshwater microalgae as organisms that contribute to the biodegradation or biotransformation of BPA in aquatic environments. When we added BPA to cultures of eight species of freshwater microalgae, a reduction in the concentration of BPA in the culture medium was observed in all cultures. BPA was metabolized to BPA glycosides by Pseudokirchneriella subcapitata, Scenedesmus acutus, Scenedesmus quadricauda, and Coelastrum reticulatum, and these metabolites were then released into the culture medium. The metabolite from P. subcapitata, S. acutus, and C. reticulatum was identified by FAB-MS and (1)H-NMR as bisphenol A-mono-O-beta-d-glucopyranoside (BPAGlc), and another metabolite, from S. quadricauda, was identified as bisphenol A-mono-O-beta-d-galactopyranoside (BPAGal). These results demonstrate that freshwater microalgae that inhabit universal environments can metabolize BPA to its glycosides. Because BPA glycosides accumulate in plants and algae, and may be digested to BPA by beta-glycosidase in animal intestines, more attention should be given to levels of BPA glycosides in the environment to estimate the ecological impact of discharged BPA.     

De novo formation characteristics of dioxins in the dry zone of an iron ore sintering bed

The objectives of this work are to understand the details of the mechanism of dioxin formation in the part of a sintering bed termed the dry zone, and to obtain ideas on how to prevent their formation. Sinter mixtures of various composition types were heated in a packed bed reactor, and dioxins in the outlet gas and in the sinter mixture residue were measured. The dioxin formation potential of a simple sinter mixture composed of iron ore, coke and limestone was markedly lower than that of fly ash from a municipal solid waste incinerator (MSWI). In consideration of this result, a series of experiments were conducted using a sinter mixture impregnated with CuCl2. Experimental results showed that dioxin formation was temperature-dependent in the range of 300-550 degrees C, with the maximum observed at around 300 degrees C, which was quite similar to that of fly ash from the MSWI. The homologue distribution of PCDD/Fs in gas and solid reflected the possible difference in carbonaceous materials in coke and activated coke. Gaseous hydrogen chloride acted as a chlorinating reagent for dioxin formation.     

CDNA microarray assessment for ozone-stressed Arabidopsis thaliana

Various detrimental factors in the environment damage plants, resulting in growth inhibition or withering. However, it is not easy to identify causal factors by visually inspecting the damaged plants. Therefore, we have developed a sensitive and reliable method for plant diagnosis, based on measuring changes in expression of a set of genes in a DNA microarray. With this method, we have been able to detect and discriminate between plants stressed by ozone, drought, or wounding.     

Do regular sea urchins show preference in which part of the body they orient forward in their walk?

Regular sea urchins, which have pentaradial symmetry, have been believed to show no preference in which part of the body forward they proceed with. Through use of circular statistics, we show that the regular sea urchin Hemicentrotus pulcherrimus had no preference with respect to what body part, as determined by Lovén’s system, should be anterior in locomotion. The sea urchins, however, preferably proceeded with the body part, which had contacted with the aquarium walls at rest, forward. When the contact part was artificially altered, the body part facing forward in the following proceeding changed accordingly: the animals walked with the part that had contacted last forward. The biological significance of this behavior was discussed in relation to the aggregation formation and homing behavior.     

Bilateral symmetry and locomotion: do elliptical regular sea urchins proceed along their longer body axis?

Vagile animals usually have bilaterally symmetrical bodies and proceed with their mouth-end first. Regular sea urchins have, however, radially symmetrical bodies with their mouth facing the substratum and show no preference in which side of the body should be anterior in their locomotion. The elliptical sea urchins in the subfamily Echinometrinae are exceptional among regular sea urchins in having elongated bilateral bodies. We studied whether they showed the preference in the direction of locomotion using Echinometra sp. type A. Directional preference was not observed in the proceedings in an open space. However, they proceeded preferentially with their long axis coinciding with the direction of locomotion when they moved along the water surface or along the wall of the aquarium. The speed of locomotion was the same irrespective of the direction of proceedings and of whether sea urchins moved freely or moved along the water surface or along the walls. We suggest that the bilateral body form and the habit of long-axis lead of this sea urchin have adaptive significance to increase the protected body surfaces, not to facilitate the efficiency in locomotion.     

Effects of a composition change of ordinary Portland cement on waste utilization and CO2 emissions in Japan

Journal of Material Cycles and Waste Management - This paper estimates the effects of a composition change of ordinary Portland cement on waste utilization and CO2 emissions in the Japanese cement...     

Virological Characterization of Roof-Harvested Rainwater of Densely Urbanized Low-Income Region

Food and Environmental Virology - Roof-harvested rainwater (RHRW) is considered relatively clean water, even though the possible presence of pathogens in the water may pose human health risks. In...     

Pyrosequencing Analysis of Norovirus Genogroup II Distribution in Sewage and Oysters: First Detection of GII.17 Kawasaki 2014 in Oysters

Norovirus GII.3, GII.4, and GII.17 were detected using pyrosequencing in sewage and oysters in January and February 2015, in Japan. The strains in sewage and oyster samples were genetically identical or similar, predominant strains belonging to GII.17 Kawasaki 2014 lineage. This is the first report of GII.17 Kawasaki 2014 in oysters.