Relation of dietary inorganic arsenic exposure and urinary inorganic arsenic metabolites excretion in Japanese subjects

Inorganic arsenic (InAs) is a ubiquitous metalloid that has been shown to exert multiple adverse health outcomes. Urinary InAs and its metabolite concentration has been used as a biomarker of arsenic (As) exposure in some epidemiological studies, however, quantitative relationship between daily InAs exposure and urinary InAs metabolites concentration has not been well characterized. We collected a set of 24-h duplicated diet and spot urine sample of the next morning of diet sampling from 20 male and 19 female subjects in Japan from August 2011 to October 2012. Concentrations of As species in duplicated diet and urine samples were determined by using liquid chromatography-ICP mass spectrometry with a hydride generation system. Sum of the concentrations of urinary InAs and methylarsonic acid (MMA) was used as a measure of InAs exposure. Daily dietary InAs exposure was estimated to be 0.087 µg kg^?1 day^?1 (Geometric mean, GM), and GM of urinary InAs+MMA concentrations was 3.5 ng mL^?1. Analysis of covariance did not find gender-difference in regression coefficients as significant (P > 0.05). Regression equation Log ₁₀ [urinary InAs+MMA concentration] = 0.570× Log ₁₀ [dietary InAs exposure level per body weight] + 1.15 was obtained for whole data set. This equation would be valuable in converting urinary InAs concentration to daily InAs exposure, which will be important information in risk assessment.     

Immunoblot detection of enzyme proteins of peroxisomal β-oxidation in fibroblasts,amniocytes, and chorionic villous cells. Possible marker for prenatal diagnosis of Zellweger's syndrome

The amounts of enzyme proteins of peroxisomal β-oxidation in fibroblasts and chorionic villous cells from infants with Zellweger syndrome and in fibroblasts, amniocytes, and chorionic villi from healthy controls were measured by immunoblot analysis. Immunoreactive proteins of peroxisomal acyl-CoA oxidase and 3-ketoacyl-CoA thiolase were absent in fibroblasts and chorionic villous cells from the patients, yet these enzyme proteins were present in fibroblasts, cultured amniocytes, and chorionic villi from the normal controls. These results show that immunoblot analysis of peroxisomal β-oxidation enzymes in amniocytes and chorionic villous cells is of potential value for the prenatal detection of Zellweger syndrome.     

Photochemical nitrosation of dimethylamine in aqueous solution containing nitrite

Dimethylamine was found to be nitrosated photochemically in aqueous solution containing nitrite both by the irradiation with a high pressure mercury lamp and by the exposure to sunlight to give nitrosodimethylamine, a well-known carcinogen. The nitrosation occurred more readily at alkaline pH than at acidic and neutral pH. These findings suggest that nitrosodimethylamine is produced photochemically under natural environmental conditions.     

The influence of forest fires on CO, HCN, C2H6, and C2H2 over northern Japan measured by infrared solar spectroscopy

Total column abundances of CO, HCN, C₂H₆, and C₂H₂ have been retrieved from infrared solar spectra observed at Moshiri (44.4°N) and Rikubetsu (43.5°N) in northern Japan from 1997 to 2005. The spectra were recorded with high spectral resolution ground-based Fourier transform infrared (FTIR) spectrometers and total column abundances were calculated by SFIT1 version 1.09e. Deviations of these species relative to their seasonal mean values (ΔCO, ΔHCN, ΔC₂H₆, and ΔC₂H₂) were derived, which showed short-time enhancements in 1998, 2002, and 2003. Good correlations among ΔCO, ΔHCN, ΔC₂H₆, and ΔC₂H₂ in a few months of each year were seen. Since the number of forest fires in Siberia had large enhancements in 1998, 2002, and 2003, trajectory analyses were performed in order to assess the influence of forest fires and it was confirmed that air masses passing over the location of burning points in Siberia reached Moshiri and Rikubetsu. This paper shows that enhancements of these species were driven by biomass burning in Siberia.     

Simulation of long-term environmental dynamics of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans using the dynamic multimedia environmental fate model and its implication to the time trend analysis of dioxins

Long term environmental fate of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were studied using the fugacity-based dynamic multimedia environmental fate model. New formulation about soil wind erosion into air was included into the model. Effect of process assumption, sensitivity analysis for parameters, and tentative validation against the measured sediment core analysis was performed. Mass fluxes between compartments were estimated by the dynamic modeling. From the model estimates, major mass fluxes coming from emission source were shown to go to the soil and water through wet/dry deposition, then go to degradation mainly in the soil and sediment. Major mass fluxes of TCDD and OCDD come from the impurities in CNP (Chlornitrofen) and PCP (Pentachlorophenol) directly into the soil. Consideration about multimedia environmental dynamics using the modeled mass fluxes was shown in the discussion.     

Carbon Sequestration by Carbonization of Biomass and Forestation: Three Case Studies

We proposed the carbon sink project called “Carbon Sequestration by Forestation and Carbonization (CFC),” which involves biomass utilization and land conservation by incorporating the products of biomass carbonization into the agents for soil improvement, water purification, etc. Our purpose was to demonstrate the potential of the CFC scheme for carbon sequestration, particularly carbon storage in soil. Case studies were conducted in both developing and developed countries. 1. In southern Sumatra, Indonesia, 88,369 Mg-C year⁻¹ of wood residue from a plantation forest and excess bark from a pulp mill would be converted into 15,571 Mg-C year⁻¹ of the net carbon sink by biochar for soil improvement. The fixed carbon recovery of the system is 21.0%. 2. In a semiarid region in western Australia, the carbonization of wood residue was incorporated with multipurpose projects of a mallee eucalyptus plantation that involved the function of salinity prevention. During the project period of 35 years, the total carbon sink would reach 1,035,450 Mg-C with 14.0% by aboveground biomass, 33.1% by belowground biomass and 52.8% by biochar in soil. 3. In southern Kyushu, Japan, the study was focused on the effective use of surplus heat from a garbage incinerator for carbonizing woody materials. Sawdust of 936.0 Mg-C year⁻¹ would be converted into the net carbon sink of 298.5 Mg-C year⁻¹ by carbonization, with the fixed carbon recovery of the system being 31.9%. Consequently, the CFC project could encourage the creation of a carbon sink in soil. However, we recognize that the quality standard of biochar, the stability of biochar in soil, and the methods for monitoring biochar utilization must be clarified before incorporating biochar carbon into the carbon credit system. Throughout this article (except for diagrams and in citation details) carbonized biomass is, with the authors'agreement, called ‘biochar’ in lieu of the commonly used but misleading word ‘charcoal’ (Editor).