In general, paint-solvents contain a large amount of volatile aromatic (VA) hydrocarbons above C7 (toluene), which give a large effect to urban atmosheric none methane hydrocarbons (NMHC) in Japan . The emissions of VA C9 hydrocarbons (VACS) from some types of industrial painting, paint making and printing processes were investigated besides those of VAC7 and VAC8 hydrocarbons (VAC7 ; VAC8). The percentages of VAC7-VAC9 in the NMHC emitted from these industrial processes changed as follows. (1) The percentages of VAC9 in the NMHC emitted from the painting processes on polymer film were very low (VAC9 average percentages= 6 .0%), while those of VAC7 and VAC8 were high (VAC7 average percentages=18.6%, VAC8 average percentages=40.4%). (2) In the NMHC emitted from the painting processes on metal board, the percentages of VAC8 and VAC9 were high (VAC8 average percentages=24.8%, VAC9 average percentages=27 .7%), while those of VAC7 were very low (VAC7 average percentages=4.3%). (3) The percentages of VAC7, VAC8 and VAC9 in the NMHC emitted from paint making processes were in good agreement with those observed at the painting processes described above . (4) The percentages of VAC7 and VAC9 in the NMHC emitted from printing processes were much lower than those of VAC8 (VAC8 percentages above 33.7%, VAC7 percentages below 2.2%, VAC9 percentages below 9.6%).

View full abstract

Natural nitrogen isotope ratio and the concentrations of inorganic ions were measured during 24 or more hours at two points along Tamagawa Jousui Channel, which was a near-natural waterway without inflow and outflow, and where treated water was discharged from the sewage treatment plant. During flowing down in ten hours, the ammonium and nitrite concentrations decreased, the nitrate concentrations increased, the loads of total inorgainc nitro gen decreased, and ¹⁵N isotopic enrichment of the residual nitrate and total in organic nitrogen were observed. Moreover, the alkalinity increased just when the loads of total inorganic nitrogen decreased largely. These results are considered to represent denitrification as well as nitrification occurring in Tamagawa Jousui Channel. The isotopic enrichment factor of the denitrification varied from -9.6 %o to-32.3 %o, almost equal to the values of those in previous studies reported by other investigators. It was indicated that use of ¹⁵N natural isotope tracer, in addition to the amounts of changes in loadings and concentrations of pollutant matters, can be effective to directly evaluate the self-purification of rivers.

View full abstract

Rain samples were collected sequentially (each about 1mm) through rain events on 9-10 June, 27 August, and 19 October 1989 at Nagatsuta campus, Tokyo Institute of Technology. The concentrations of F^- and Br^- ions ranged from 0.20 to 53.8μg/l and from 0.74 to 19.0μg/l in three rain events, respectively. The ratios of F^-/Cl^- were high at the initial stage and gradually decreased. There was a high correlation between concentrations of Ca2⁺ and F^- in three rain events, whose coefficient was 0.97, 0.89, 0.99 for rain events on 9-10 June, 27 August, and 19 October, respectively. On the other hand, the ratios of Br^-/Cl^- were approximately equal to the sea salt ratio (3.4×10^-3). However, in rain events on 9-10 June and 19 October, the ratios of Br/C1^- largely exceeded sea salt ratio at the middle or final stages of the events. There was a high correlation between N03^- and non-sea salt Br^- indicating that anthropogenic Br^- was loaded on precipitation.

View full abstract

The concentrations of representative five volatile chlorocarbons, namely 1, 1, 1-trichloroethane (methylchlorof orm), trichloroethylene, tetrachloroethylene, chloroform and carbon tetrachloride, in ambient air at residential area in Musashino City andNerima Ward in Tokyo were measured by GC/MS using negative ion chemical ionization at hourly intervals, during three days (Wednesday, Thursday and Friday) in alternate months from October 1989 to August 1990 in the former and every Thursdays at January and February 1989 in the latter. The obtained results were summarized as follows. 1) Their hourly concentrations were 0.31-15.3, <0.1-6.4, 0.07-3.8, <0.1-6.6 and <0.01-2.7 ppb in Musashino City and 2.0-25.0, 0.30-16.8, 0.30-9.8, 0.18-1.8 and 0.15-0.85 ppb in Nerima Ward, respectively. The variation was fairly large and irregular. 2) In winter, relatively high concentrations were appeared because of increase of the use in dry-cleaning. Particulary, increase of 1, 1, 1-trichloroethane concentration was often observed from midnight to daybreak and correlated with NO concentration. It was considered that this fact was responsible for appearance of inversion layer. 3) Correlation between concentrations of 1, 1, 1-trichloroethane, trichloroethylene and tetrachloroethylene were found. They may begenerated from the same emission sources. 4) Correlations between chlorocarbon concentrations and several weather conditions such as temperature, humidity and direction of wind were poor, but the wind speed was correlated inversely to the concentrations.

View full abstract

External magnetic fields (45-200mT) did not affect the X-ray- and ultraviolet (UV)-induced cell killing rates determined by measuring numbers of colony formation in cultured mammalian cells. A magnetic field (80mT) did not influence the relative yield of UV-induced DNA damage (both cyclobutane pyrimidine dimers and (6-4) photodimers) in calf thymus DNA detected by the enzyme-linked immunosorbent assay (ELISA) with a monoclonal antibody. No magnetic field effect was also observed on the formation of UV-B-induced cyclobutane thymine dimer in the presence of acetophenone as triplet sensitizer.

View full abstract

Cadmium, zinc and copper levels were investigated for running water in head, middle and lower reaches of the three major rivers, TONEGAWA, ARAKAWA and NAKAGAWA, in KANTO district. Cadmium and zinc concentrations were deter mined for filtrate and residue with 0.45pm membrane filter. Copper was determined for filtrate of water with and without acid amendment . Soluble cadmium ranged 0.008-0.043 in the river heads and shifted up to 0.030-0.091μg/l in the lower reaches. Soluble zinc ranged 1 .2.4.3 in the river heads and 5.1-18.4μg/l in the lower reaches. Suspended cadmium and zinc levels were compa rable with those of the soluble forms . Soluble copper with acid amendment ranged 1.80-4.76 in the river heads and apparently increased up to 6.50-17.7μg/l in the lower reaches. The levels of metals in the river heads may represent the natural abundance, and the background levels may be defined from those in the middle and lower reaches of the rivers.

View full abstract

The feasibility of CO2 emission reduction by residents'actions was evaluated and their inhibiting factors were analyzed by type of families, using questionnaire survey to 1, 050 respondents in Matsudo and Maebashi. The results are as follows ;1) The amount of feasible reduction was estimated at about 2% of total domestic emissions from energy consumption. The effective actions to reduce emissions are “ cutting family car use”, “ choosing a fuel efficient car ”, “insulating of houses”.2) The main inhibiting factors were ; a) sanitary problem and time-consuming are the main inhibiting factors for housekeeping and efficient resource use action, b) social customs for lifestyle, c) the cost for insulation, and d) recreational activities for caruse.3) The analysis by family type revealed that families in rural areas and those other than salary earners have larger practicability of the actions than those with frequent house moving and big families.

View full abstract