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A two‐stage sampler was designed to investigate the vertical distribution of heavy metals and trace elements that contaminate forest soils through atmospheric deposition. The hand‐corer consisted of two L‐shaped aluminum angles that were driven separately into the soil to reduce friction between the corer wall and the soil. This allowed for soil cores to be collected with less compression than with traditional corers. The corer is easily made, inexpensive, lightweight, and easy to carry. The degree of compression of soil cores collected at a depth of 20 cm from various montane forests in Japan was usually less than 10% (collected core length >18 cm); although, more compression occurred in soil with a higher air content. The degree of compression of soil cores collected from urban forests was lower than that in montane forests. When the two‐stage sampler was compared with a tube‐type sampler in a Japanese cedar (Cryptomeria japonica) forest, the compression degree of a soil core collected with the two‐stage sampler was a quarter that of the tube‐type sampler. The collection of less‐compressed soil cores will allow for reconstruction of a more accurate linear depth distribution of contaminants. To demonstrate this, we investigated the vertical distribution of Pb, Sb, and radioactive 137Cs in soil cores collected from conifer plantations on Mount Tsukuba, Japan, in April 2011. The migration centers of anthropogenic Pb, Sb, and 137Cs were positioned at 7.9, 7.5, and 3.3 cm from the ground surface, respectively. These distances probably reflect differences in the history of atmospheric pollution. [ABSTRACT FROM AUTHOR]

Despite the wide use of trace metals in various technologies, such as chemical industries and electronic equipment, insufficient information is available on their behavior in the environment. We investigated changes in chemical forms and vertical distribution during the migration processes of trace metals, whose usage is currently increasing rapidly, such as Ag, In, Sn, Sb, and Bi, in soil contaminated with the equivalent of 50-100 times the background concentrations of these metals using an indoor control type monolith lysimeter filled with Andosol during an 8-year monitoring period. The vertical distribution of the total elemental concentrations, the mobile fractions (exchangeable, carbonate-bound, and metal-organic complex-bound) in soils, and the total elemental concentrations in soil solutions were analyzed to study trace metal migration in soil. Except for In, most of the added metals were retained in the uppermost (0-2 cm) soil layer, even after 8 years. However, In markedly migrated downward and accumulated at a depth of approximately 15 cm after 8 years. Furthermore, 10.0 ± 2.9 μg L of In was detected in soil solution at a depth of 17.5 cm. The mobility of In was probably caused by the acidity of the soil, because the pH of the soil between 0 and 15-cm depth was 5 and below, and soluble hydro-oxides, such as In(OH)aq and In(OH), might be produced at this pH. Consequently, the remarkable mobility of In occurred in Andosol, which strongly retains various trace metals. The proportions of the mobile fractions observed in this study indicated that the mobility of the five metals in Andosol occurred in the order In > Bi ≥ Sb ≥ Sn > Ag. [ABSTRACT FROM AUTHOR]

The average composition of water, bottom sediments, manganese (Mn) crusts, and Mn concretions from Lake Biwa (the largest freshwater lake in Japan) are re-examined, in conjunction with those of seawater, oceanic pelagic clay, and deep-sea Mn nodules. The purpose is to gain additional insights into the geochemical behaviors of elements in Lake Biwa and the ocean, which are quite different in ionic strength (or salinity), pH, water residence times, sediment accumulation rates, carbon fluxes to sediments, and the redox potential in sediments. Excluding a few millimeters of oxic surface sediment, there is no appreciable accumulation of Mn in the Lake Biwa bottom sediments due to reducing condition there. Consequently, other B-type cations [such as iron (Fe), gallium (Ga), copper (Cu), lead (Pb), cobalt (Co), tin (Sn), and bismuth (Bi), with subshell valence electron configuration of d] are also less concentrated in the lake sediments than in the oceanic pelagic clay. In turn, B-type cations have much higher dissolved concentrations in the lake water than in the ocean. The rare earth elements (REE) mainly form organic complexes in the lake water and carbonate complexes in the ocean. REE are mostly associated with detritus aluminosilicate phases in Lake Biwa sediments but with phosphate phases in deep-sea sediments. Fe and Mn oxide phases are clearly separated in marine Mn nodules and crusts but not in Mn crusts and concretions from Lake Biwa. Useful parameters such as the enrichment factor ( E) and logarithms of the distribution coefficient (log K) of elements between solid and liquid phases were estimated in both systems for further discussions. [ABSTRACT FROM AUTHOR]

The effects of phosphate starvation and subsequent up-take on distribution and concentration of phosphate metabolic intermediates and metals were studies in Heterosigama akashiwo (Hada) Hada by "P-NMR spectroscopy, neutron activation analysis and ESR spectroscopy. Excess orthophosphate (4.5 μM P as Na H2PO) added to a medium with P-depleted H. akashiwo cells was rapidly taken up resulting in an increase in P cell quota (q[SUBe]) from 68.2 to 99.6 fmol cell[SUP-1] in 2 h and to 156.3 fmol cell[SUP-1] in 6 h. after three days, q[SUBp] approached about 190 fmol cell[SUP-1] Polyphosphate (PP) rapidly increased from 0 to 11.4 f mol cell[SUP-1] in 2 h and to 24.7 fmol cell[SUP-1] in 6 h. Diel variation of cell quota indicated that cellular P[SUBi]. increase was synchronized with cellular PP decrease and vice versa. The average chain length of PP[SUBi] increased from ca 0 to ca. 10.2 phosphate residues in 2 h after addition of P[SUBi] and one day later, from ca. 9.8 to ca. 12.5. The cell quota of Mn (q[SUBMn]), and to a lesser extent Co, increased rapidly from 4.87 fg · cell[SUP-1] in the P- starved condition to 50.48 fg · cell[SUP-1] 2 h after addition of P[SUBi] but decreased to 8.63 fg · cell[SUP-1] by 6 h. Concentrations of Zn, As, Hf, Cu, and sometimes Al, Mg, K, and Ca changed in a manner opposite to that of Mn and Co. The excretion of these cations, which was synchronized with the uptake of Mn and Co, may be important for a charge balancing in the cells. The ESR spectra showed that the high cellular Mn observed at 2 h after P addition was Mn[SUP2+] which was taken up by the cells rather than adsorbed on the cell surface. These data combined with PP[SUBi] data suggested that the behavior of q[SUBMn] is synchronized with the behavior of average chain length of PP[SUBi]. [ABSTRACT FROM AUTHOR]