Distribution of six anticancer drugs and a variety of other pharmaceuticals,and their sorption onto sediments,in an urban Japanese river

Environmental Science and Pollution Research - The distributions of 31 pharmaceuticals grouped into nine therapeutic classes, including six anticancer drugs, were investigated in the waters and...     

Isomer distribution of nitrotriphenylenes in airborne particles, diesel exhaust particles, and the products of gas-phase radical-initiated nitration of triphenylene

The formation of mutagenic nitro-polycyclic aromatic hydrocarbons (NPAHs) 1- and 2-nitrotriphenylene (1- and 2-NTP) via gas-phase OH or NO₃ radical-initiated reactions of triphenylene was demonstrated for the first time using a flow reaction system. In contrast with the results of conventional electrophilic nitration, 2-NTP was formed in larger yield than 1-NTP, but this is consistent with the mechanism proposed for gas-phase radical-initiated nitration of PAH. In diesel exhaust particle (DEP) samples, both 1- and 2-NTP were identified and their concentrations determined, as well as 1-nitropyrene (1-NP), which is a representative combustion-derived NPAH: the mean concentrations of 1-NTP, 2-NTP, and 1-NP were 4.7, 1.9, and 32 pmol mg_DEP^–1, respectively. The mean 2-NTP/1-NTP, 1-NTP/1-NP, and 2-NTP/1-NP ratios in samples of airborne particles collected in a residential area in Osaka, Japan, were>1.55,<0.25, and 0.37, respectively; these values are much higher than those of the DEP samples. This finding indicates that there is another source for airborne NTPs, especially 2-NTP, apart from diesel exhaust. These results strongly suggest that airborne NTPs originate from atmospheric processes such as radical-initiated reactions of triphenylene, and this has a significant influence on the atmospheric occurrence of NTPs.     

Mutagenic nitrated benzo[a]pyrene derivatives in the reaction product of benzo[a]pyrene in NO2-air in the presence of O3 or under photoirradiation

In order to clarify the contribution of nitrated products to the direct-mutagenic activity of products of the reactions of benzo[a]pyrene in NO2-air under various conditions, heterogeneous reactions of BaP deposited on filter in the air containing 10 ppm of NO2 have been conducted in dark or under photoirradiation. The reaction products have been analyzed by gas chromatography and mutagenicity of the products fractionated by preparative HPLC was assayed for Salmonella typhimurium strains TA98 and YG1024 in the absence of S9 mix. 3,6-dinitrobenzo[a]pyrene and 1,3-dinitrobenzo[a]pyrene, which are strong direct-acting mutagens, largely contributed to the total direct-acting mutagenicity of the dark reaction products in NO2-air. On the other hand, both the dark reaction in the presence of O3 and the photoreaction in NO2-air resulted in the formation of much smaller amounts of nitrobenzo[a]pyrenes than that observed in the dark reaction in the absence of O3. These results show that the contribution of other direct-acting mutagens to the total direct-acting mutagenicity of the products in these reactions should be considered. Benzo[a]pyrene lactones were identified in a highly mutagenic fraction of the products of the dark reaction in the presence of O3 and photoreaction and a nitrobenzo[a]pyrene lactone was also identified in a highly mutagenic fraction of the dark reaction products in the presence of O3. Nitrated oxygenated benzo[a]pyrene derivatives such as nitrobenzo[a]pyrene lactone were considered to largely contribute to direct-acting mutagenicity of the products of the dark reaction in the presence of O3 and photoreaction.     

Association of the mutagenicity of airborne particles with the direct emission from combustion processes investigated in Osaka, Japan

The association of the direct-acting mutagenicity of soluble organic fraction of airborne particles toward Salmonella typhimurium YG1024 strain with the direct emission was investigated at a roadside and at a residential area in Osaka, Japan. The direct-acting mutagenicity was evaluated as mutagenic activity per unit volume of ambient air (rev m⁻³) and/or that per airborne particulate weight collected on a filter (rev mg⁻¹). The annual or diurnal changes of the mutagenicity of airborne particles at the residential site showed similar patterns to those of some gaseous pollutants such as NO₂ and SO₂, which were emitted from combustion processes. This result indicates that the mutagenicity is mainly attributable to the primary emissions. From the analysis of the relationship between the wind sector and the mutagenic intensity, rev m⁻³ and rev mg⁻¹ values were strongly affected by the emissions from the fixed sources and from the mobile sources, respectively. The rev m⁻³ value and concentration of 1-nitropyrene (1-NP) in unit per m³ at the roadside were a factor of 2.6 and 2.8 higher than those at the residential site, respectively, but the rev mg⁻¹ value and concentration of 1-NP in unit per mg at the roadside were substantially comparable to those at the residential area. These observations suggest that the characteristics of the airborne particles can be attributed to the automotive emissions even at the suburban area.     

Rice uptake and distributions of radioactive 137Cs, stable 133Cs and K from soil

The distributions of radionuclides in plant components as to radionuclide transfer to animals are important for understanding the dynamics of radionuclides in an agricultural field. Most of the non-edible parts in these components are returned to the soil as organic fertilizer where they may again be utilized in the soil-plant pathway and/or are mixed with feed for livestock. Rice plants were grown in an experimental field and separated at harvest into different components, including polished rice, rice bran, hull, leaves, stem and root, and then the distributions of radioactive 137Cs, stable 133Cs and K in these components were determined. The distribution of 137Cs in polished rice and rice bran was similar to that of 133Cs, while that of K was different. The concentration ratios of 133Cs/K in leaf blade positions increased with aging, which means that the translocation rate of 133Cs in rice plants was slower than that of K. At harvest the distribution of dry weight in polished rice to entire rice plants was 34%, and the distributions of 133Cs in the polished rice and the non-edible parts were 7 and 93%, respectively, whereas those of K in the polished rice and the non-edible parts were 2 and 98%, respectively. Findings suggest that the transfer and distribution of 133Cs, not of K, provide better information on the long-term fate of 137Cs in an agricultural environment.     

Tritium concentrations in the atmospheric environment at Rokkasho, Japan before the final testing of the spent nuclear fuel reprocessing plant

This study aimed at obtaining background tritium concentrations in precipitation and air at Rokkasho where the first commercial spent nuclear fuel reprocessing plant in Japan has been under construction. Tritium concentration in monthly precipitation during fiscal years 2001-2005 had a seasonal variation pattern which was high in spring and low in summer. The tritium concentration was higher than that observed at Chiba City as a whole. The seasonal peak concentration at Rokkasho was generally higher than that at Chiba City, while the baseline concentrations of both were similar. The reason for the difference may be the effect of air mass from the Asian continent which is considered to have high tritium concentration. Atmospheric tritium was operationally separated into HTO, HT and hydrocarbon (CH₃T) fractions, and the samples collected every 3 d-14 d during fiscal year 2005 were analyzed for these fractions. The HTO concentration as radioactivity in water correlated well with that in the precipitation samples. The HT concentration was the highest among the chemical forms analyzed, followed by the HTO and CH₃T concentrations. The HT and CH₃T concentrations did not have clear seasonal variation patterns. The HT concentration followed the decline previously reported by Mason and Östlund with an apparent half-life of 4.8 y. The apparent and environmental half-lives of CH₃T were estimated as 9.2 y and 36.5 y, respectively, by combining the present data with literature data. The Intergovernmental Panel on Climate Change used the atmospheric lifetime of 12 y for CH₄ to estimate global warming in its 2007 report. The longer environmental half-life of CH₃T suggested its supply from other sources than past nuclear weapon testing in the atmosphere.     

Plant induced changes in concentrations of caesium, strontium and uranium in soil solution with reference to major ions and dissolved organic matter

For a better understanding of the soil-to-plant transfer of radionuclides, their behavior in the soil solution should be elucidated, especially at the interface between plant roots and soil particles, where conditions differ greatly from the bulk soil because of plant activity. This study determined the concentration of stable Cs and Sr, and U in the soil solution, under plant growing conditions. The leafy vegetable komatsuna (Brassica rapa L.) was cultivated for 26 days in pots, where the rhizosphere soil was separated from the non-rhizosphere soil by a nylon net screen. The concentrations of Cs and Sr in the rhizosphere soil solution decreased with time, and were controlled by K+NH(4)(+) and Ca, respectively. On the other hand, the concentration of U in the rhizosphere soil solution increased with time, and was related to the changes of DOC; however, this relationship was different between the rhizosphere and non-rhizosphere soil.     

Exoenzymes of Trametes versicolor can metabolize coplanar PCB congeners and hydroxy PCB

Two fractions containing the oxidase activity toward 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) were obtained using ion-exchange DEAE-Sepharose column chromatography of the culture fluid of white-rot fungus, Trametes versicolor. These two fractions can reduce the level of coplanar PCB congeners (Co-PCBs). The ABTS oxidase in the first fraction passed through the DEAE-Sepharose column. The ABTS oxidase in the second fraction was adsorbed to the column at 相似文献   

Measurement of Trace Levels of Atmospheric Sulfur Dioxide with a Gold Film Sensor

The mercury translation principle, wherein S(IV) reacts with Hg(l) to produce Hg(ll) and Hg(O), was utilized to measure trace levels of SO₂ with a conductometric gold film sensor. One approach involved impregnated glass fiber filters containing mercurous salts. The second and more successful approach utilized a porous membrane reactor where the reaction occurs in the interstitial liquid-gas interface as the sample gas flows inside and a dilute solution of Hg₂(NO₃)₂ flows outside the porous PTFE membrane tube. The first approach attained a LOD of 200 pptv SO₂(g), however, batch to batch reproducibility of the filters was poor and the filters could not be stored more than two days. The membrane reactor method provided better translation efficiency and highly reproducible results, with an LOD of 50 pptv SO₂(g). An intercomparlson of this method with an independent method relying on completely different chemistry showed good agreement for the measurement of subppbv levels of ambient SO₂. Both mercury translation methods were essentially unaffected by H₂S or CH₃SH.