In the downtown of Japanese big cities, lots of buildings with underground floors are in place. In order to carry wastewater from the underground floor to public sewers, pumps are used because underground floors are below the level of cleanout leading to public sewer. In some pits, wastewater remains for many hours because entering wastewater amount is so small that pumps do not operate regularly. This causes anaerobic reaction of wastewater in the pits. When the pumps start operating, corroded wastewater is discharged to public sewers releasing H₂S gas. The odorous gas comes up to the busy streets nearby through gully pots in combined sewer system or openings of manhole or cleanout covers in separate and combined system. Under Japanese administration system, the buildings with odor subjects to odor control law. This law is operated by environmental control offices of local governments. However, the problems occur through sewer systems. So lots of citizen complaints are coming to sewer operators for this problem. Sewer operators have had no means to correct the problematic buildings. This lack of coordination between environmental offices and sewer operators is caused partly by lack of knowledge about relation of water quality of discharge for regulation and H₂S concentration observed in cleanouts of sewer system. In this paper, characteristics of odor generation by discharge of wastewater from underground pits to above sewers were clarified.

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Plants commonly respond to environmental stress with a production and /or release of specific flavor components. Some of the secondary induced chemicals are known to work as allelochemics. On the other hand, recent reports say atmospheric concentration of carbon dioxide (CO₂) tends to increase on a global basis. This study aims to investigate the potential effect of CO₂ level on the metabolite and release of flavor components of plants. Flavor components from/in the leaves of five kinds of herbs were determined by Head Space and MTBE extraction methods coupled with Gas Chromatography/Mass Spectrometer under both ambient CO₂ concentration and elevated level (ca. 700ppm, double the present atmosphere) in a growth chamber. Significant differences were found for herbaceous plants such as Ocimum basilicum, Origanum vulgare and Mellissa officinalis, in emissions, extracted amounts and chemical compositions of terpenoids and phenypropanoids, when exposed to the elevated CO₂ concentration. Meanwhile, no apparent changes were found for woody plants such as Salvia elegans and Eucalyptus citriodor. This means a change in CO₂ concentration is a possible environmental stress at least on the herbaceous plants, whose photosynthetic rates are commonly greater than those of woody plants.

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A new apparatus for decomposing volatile organic compounds(VOCs) targeted at the small-scale factories was developed by our joint industry-university-local government research project funded by Ministry of the Environment. The prototype apparatus using the exothermic SiC honeycomb was improved in the points of treatment gas-flow, energy-saving and catalytic decomposition capacity after our previous report. As a result, the capacity of gas treatment and the reduction rate of energy-saving at SV(Space Velocity)=3,300 could be elevated up to 300 m3/h and 40%, respectively. The catalytic decomposition was approximately 10% more effective than that of the previous system. In the demonstrative examination at a metal painting factory and a printing factory, the removal rate of VOCs reached 95% and the deodorization efficiency was 98%. The improvement of exhaust ventilation system in the actual process of the factories and the incorporation more than one apparatus would be needed for the practical adaptation of the proposed apparatus.

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We evaluated the body odor of five dogs using the Triangular Odor Bag Method. In order to observe the values of “dilution ratio to the detection threshold (D/T)”, a panel was used to measure odor samples captured from 9 to 31 days after shampooing. This allowed us to measure D/T values of 1, 5, 10, 20, 50, 100 and 200. Though the odor indexes [=10log (D/T)] increased each day after shampooing, they plateaued after the 24th day. Odor index values, intensity, and acceptability were measured using five dogs' odor samples 19 to 105 days after shampooing. A significant positive correlation was found between the days after shampooing and odor indexes (y=0.19x, r=0.89, p<0.05). A statistically significant correlation was not found between the odor index and intensity (y=0.09x+1, r=0.39, NS). On the other hand, although the odor index tended to become high when the acceptability became low, statistically significant correlation was not found between them (y=-0.02x, r=-0.06, NS). In conclusion, we found that we could measure and evaluate the dog's odor by using Triangular Odor Bag Method in this study.

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