1,2,5,6,9,10-hexabromocyclododecane diastereomers (HBCDs) are used as flame retardants in thermal insulation building materials, upholstery textiles, and electronics. Due to the widespread use and the physical and chemical properties, HBCDs are now ubiquitous contaminants in the environment. The environmental distribution and behavior are to be revealed. In Nagoya city, HBCDs have been detected with a high frequency in the environment in various compartments.
In the present paper, we report a measurement method and concentrations of HBCDs in various environmental compartments (water, sediment, and biological samples) in Nagoya city, and discuss on environmental distribution, time trends in concentrations and possibility of biodegradation.
HBCDs were detected in various water samples, of which concentrations of the total isomers ranged from <0.76 to 79 ng/L. γ-HBCD dominated over the other isomers in water samples. Similarly, sediment samples were dominated by γ-HBCD, which was detected in all samples, ranged from <1.9 to 58 ng/g-dry. In the most of fish and shellfish samples, α-HBCD was the predominant isomer of HBCDs and was found in all the samples in levels from 25 to 6300 ng/g-lipid. On the other hand, γ-HBCD was predominant similar to those in industrial products in some samples which supposed to be collected near the discharge point. In breast milk, α-HBCD was also predominant and was found in all samples in concentrations from <3.7 to 13 ng/g-lipid.
In the degradation experiments of HBCDs with sediments, potential for biodegradation was implied under anaerobic condition.

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A survey of perfluorinated chemicals (PFCs) deposition during winter was performed at rural areas and hinterlands in Hokkaido (9 points). The depositions were calculated from the concentrations of PFCs in snow covers. The PFCs concentrations were 2.3 ∼ 12 ng/kg. PFBA was the dominant compound, and PFOA and PFNA were also detected. The deposition amounts and amount rates of PFCs were 0.38 ∼ 8.6 μg/m² and 5.7 ∼ 95 ng/m²/day, respectively. They were high in the area along the Sea of Japan. The concentrations of some of PFCs among detected PFCs were higher than those in the snowfall at metropolitan area. The result shows not only wet deposition but dry deposition and/or chemical reaction of precursors also contributed to the deposition during the winter.

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A wireless sensor network was developed for continuously measuring ozone concentration in the atmosphere. The network was constructed of sensor nodes, each of which was made of an ozone sensor and a communications transmitter connected to a cellular phone network. In order to examine the performance of the sensor network, one-year observations were made at local air pollution monitoring stations in Sapporo and in Ayabe (in Kyoto Prefecture), and the ozone concentrations derived from the sensor outputs were compared with those obtained by the standard monitoring instruments. As a result, it was proved that the ozone sensor used in the node had enough ability to follow the change in the ozone concentration in the atmosphere. The correlation coefficients between the sensor network and the monitoring-station observations exceeded 0.86. Thus the ozone monitoring sensor network developed in this study was found to be at a stage of practical application.

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