Partitioning between soluble and insoluble fractions of major and trace elements in size-classified airborne particulate matter collected in Tokyo

Airborne particulate matter (APM) is a major air pollutant, and the effect on human health of fine APM (PM2.5) deposited deep inside the lungs has recently become a serious concern. Moreover, soluble constituents may leach from APM, and intensify some health disorders. To identify the soluble chemical constituents of APM, size-classified APM was sampled in central Tokyo, and the elemental compositions of the water-soluble, acid-soluble and insoluble fractions were investigated. The extraction procedure was validated by calculating the mass balance of soluble and insoluble fractions of a standard APM reference material (NIST SRM 1648). Among the major elements, Fe and Ti in APM of all size classes and K in coarse APM were distributed primarily in the insoluble fraction and were inferred to be present as oxides or silicates, whereas Na and Mg in all size classes and K in fine APM were primarily in the water-soluble fraction and were inferred to be have originated mainly from sea salt. Among the trace elements, Zn and Cd in the fine APM (d < 2 microm) had large enrichment factors, indicating an anthropogenic origin, and were distributed primarily in the water-soluble fraction. When fine anthropogenic APM enters into the lungs, leached toxic elements, such as Cd, may adversely affect health. The higher the bonding energy of the monoxide molecule of the element was, the higher its distribution ratio was in the water-soluble fraction. Therefore, many metallic elements in APM were inferred to be present as oxygen-bonded compounds.     

Identification and characterization of coagulation inhibitor proteins derived from cyanobacterium Microcystis aeruginosa

The excess growth of cyanobacteria in semi enclosed water areas caused by eutrophication brings about coagulation inhibition in drinking water treatment processes. In this study, coagulation inhibitor proteins produced by Microcystis aeruginosa, a major cyanobacterium in algal bloom, were acquired by a phage display technique, an aluminum-immobilized affinity chromatography and a protein expression technique using Escherichia coli cells. Two cyanobacterial peptides with a high ratio of metallophilic amino acids were recovered, which were a part of homologues of a thiol oxidase enzyme Ero1p and a trans-acting repressor ArsR. It was also shown that the homologue of ArsR exhibited a stronger inhibitory effect on the coagulation of kaolin suspension with polyaluminum chloride than the control proteins. This is the first report to identify a cyanobacterial cell component to inhibit coagulation. The compositions of polar amino acids were critical to explain the strength of coagulation inhibition potential. Polar proteins from cyanobacteria could collectively consume coagulants or stabilize clay particles, which would be plausible explanations for causing coagulation inhibition. Meanwhile, results from the kaolin coagulation tests using the control proteins implied that the neutralization of positive charges of coagulant constituents by simple electrostatic interactions might not be the key mechanism on the protein-induced coagulation inhibition.     

Measuring future dynamics of genuine saving with changes of population and technology: application of an integrated assessment model

Theoretical and empirical studies have been conducted on the genuine saving (GS) based on neoclassical economic theory to assess sustainable development (SD). However, only market prices and statistical national accounts have been used in empirical studies due to limited data availability. The data availability limits to measure GS only in the past and current, causing a wide gap with theoretical results. In this paper, we propose computing GS using an integrated assessment model (IAM) as connected to the mainframe model of macroeconomy. This enables us to use shadow prices, rather than market prices, obtained through an IAM, which ensures substantial consistency among variables. An example would be endogenous capital–output ratio and the rate of TFP. Also, our indicator of GS is more comprehensive in that they now account for various resources, environmental degradation, and land use. Our simulation results, with a particular focus on GS with population change (GSn) and with technological change as well (GSnt), show a sustainable future for up to the end of the century thanks to declining population in the latter half of the century and technological progress, although GS without accounting for population and technology tend to be negative, driven by, among others, capital depreciation and net primary productivity degraded by land use.     

Sorption of dissolved lead from shooting range soils using hydroxyapatite amendments synthesized from industrial byproducts as affected by varying pH conditions

For immobilization technologies to be successful, the use of readily available and cost advantageous amendment is important when the remediation targets vast amounts of contaminated soils. The objectives of this study were to investigate whether the byproduct-synthesized hydroxyapatite can be used as an immobilizing amendment for dissolved Pb from a shooting range soil, and to model the kinetic data collected from dissolution experiments. A soil–solution kinetic experiment was conducted under fixed pH conditions as a function of time. A Pb-contaminated soil was reacted with various hydroxyapatite amendments to determine the dissolution rate and mineral products of soil Pb. Three types of amendments used were pure hydroxyapatite (HA), and poorly crystalline hydroxyapatites synthesized from gypsum waste (CHA), and synthesized from incinerated poultry litter (PHA). The dissolved Pb concentration decreased with the addition of amendments at pH 3–7. Both CHA and PHA were more effective than HA for attenuating Pb dissolution at pH 6 and above. According to the thermodynamic calculation at pH 6, the dissolved Pb concentration for CHA and PHA treatments was predicted to be 66% and 50% lower than that of HA treatment, respectively. A better Pb immobilization effect demonstrated by CHA and PHA resulted in their greater solubility at higher pH, which may promote the formation of chloropyromorphite precipitates. Dissolution kinetics of soil Pb was adequately explained by pseudo-first order and pseudo-second order equations in acid pH ranges. According to the ion exchange model, an adequate agreement between the experimental data and regression curves was shown in the initial 40 min of the reaction process, but the accuracy of model predictability decreased thereafter. According to kinetic models and dissolution phenomena, CHA and PHA amendments had better Pb sorption capacity with rapid kinetics than pure hydroxyapatite at weak acid to neutral pH.     

Effect of organic suspended solids and their sedimentation on the surrounding sea area

A study of sediment contamination was made in one of the 23 specific designated important ports in Japan, the inner part of which had been used as wood pool. The study focused on the relationship between contaminants and organic matter in terms of ignition loss and the impact of the wood pool on the port area. Organic matter exists in the form of suspended solids and deposits. Sediment samples were taken from the mouths of the rivers feeding into Shimizu Port, from the wood pool and from Shimizu Port. Samples within Shimizu Port showed that as the ignition loss decreased with distance from the wood pool, other properties including the concentrations of trace metals, ignition loss and sulfide content also decreased with the distance. In conclusion, Shimizu Port seems to function as a buffer area between the wood pool and Suruga Bay.     

Seasonal variation in the atmospheric deposition of inorganic constituents and canopy interactions in a Japanese cedar forest

The seasonal changes in throughfall (TF) and stemflow (SF) chemistry and the canopy interactions of K+ and N compounds were studied in a Japanese cedar forest near the Sea of Japan. The fluxes of most ions, including non-sea-salt SO4(2-), from TF, SF, and rainfall showed distinct seasonal trends, increasing from autumn to winter, owing to the seasonal west wind, while the fluxes of NH4+ and K+ ions from TF+SF might have a large effect of canopy interactions. The contact angle (CA) of water droplets on leaves decreased with leaf aging, suggesting that surface wettability increases with leaf age. The K+ concentration in TF was negatively correlated with the CA of 1-year-old leaves, while the NH4+ concentration was positively correlated with the CA. The net fluxes of NH4+ and NO3(-) from TF were positively correlated with the CA. The increase in wettability may accelerate leaching of K+ or uptake of NH4+.     

Attenuation of lead leachability in shooting range soils using poultry waste amendments in combination with indigenous plant species

Chemical immobilization technology utilizing poultry waste (PW) along with a native plant (Panicum maximum Jacq.) application was assessed for the attenuation of downward Pb dissolution and modification of Pb speciation in solid and liquid phases in the soil. A large column study with and without plant and PW applications was conducted using a Pb contaminated soil collected from a shooting range area. The PW application reduced water-extractable Pb by about 43% of that of the treatment without the PW and plant applications (Control). The cumulative Pb amount in column leachates over 100d was increased by the PW amendment (0.32mg) compared to Control (0.27mg), but was reduced to 0.23mg by the combined use of plant and PW amendment. Sequential extraction analysis revealed that the Pb fractions of PW-amended soils were shifted to less soluble phases as indicated by an increased residual fraction (20%) and decreased exchangeable and carbonate fractions (22%) than those in the Control soil. Thermodynamic equilibrium calculations demonstrated that predicted Pb(2+) activity was saturated with respect to cerussite in the Control soil and was supersaturated with respect to chloropyromorphite in the PW-amended soils. Our results suggest that the use of plant in combination with PW as a Pb immobilizing amendment attenuated downward Pb leaching and altered Pb species to more geochemically stable phases.     

Nematomorph parasites drive energy flow through a riparian ecosystem

Parasites are ubiquitous in natural systems and ecosystem-level effects should be proportional to the amount of biomass or energy flow altered by the parasites. Here we quantified the extent to which a manipulative parasite altered the flow of energy through a forest-stream ecosystem. In a Japanese headwater stream, camel crickets and grasshoppers (Orthoptera) were 20 times more likely to enter a stream if infected by a nematomorph parasite (Gordionus spp.), corroborating evidence that nematomorphs manipulate their hosts to seek water where the parasites emerge as free-living adults. Endangered Japanese trout (Salvelinus leucomaenis japonicus) readily ate these infected orthopterans, which due to their abundance, accounted for 60% of the annual energy intake of the trout population. Trout grew fastest in the fall, when nematomorphs were driving energy-rich orthopterans into the stream. When infected orthopterans were available, trout did not eat benthic invertebrates in proportion to their abundance, leading to the potential for cascading, indirect effects through the forest-stream ecosystem. These results provide the first quantitative evidence that a manipulative parasite can dramatically alter the flow of energy through and across ecosystems.