The concentrations of organochlorine chemicals in market fish samples collected in Korea followed the order, DDTs>PCBs>HCHs>HCB>PCDFs>PCDDs. The concentrations of organochlorines were positively correlated with the lipid contents in fish samples. Especially, there was a significant correlation between the lipid contents and the total concentrations of DDTs (r=0.71, P<0.01) and also those of PCDDs/DFs (r=0.66, P<0.01) . Namely, the concentrations of organochlorines as well as lipids in Mackerel and Hairtail are relatively high, compared with those of Yellow Tailrunner and Alaska Pollack.
The concentration order of PCDD congeners was PeCDD followed by HxCDD, TeCDD and HpCDD. On the other hand, PCDFs showed the order of TeCDF, PeCDF, HxCDF and HpCDF. OCDD and OCDF were not detected in the fish samples.
The contributions of low-chlorinated PCDDs/DFs to total PCDDs/DFs concentrations were markedly higher than those of high-chlorinated PCDDs/DFs. This phenomenon was also reflected in the percent composition of PCDDs/DFs on TEQs. Among the isomers of PCDDs/DFs, percent contribution of TEQ for 2, 3, 4, 7, 8-PeCDF on total PCDDs/DFs was shown to be 42%. This suggests that fish is a significant source of exposure for low-chlorinated PCDDs/DFs on the general population in Korea.
The daily intake of PCDDs/DFs via fish consumption was calculated to be 35.7pg/person/day for TEQ, using the 1994 Korean fish consumption rate (85g/day) . The values are equivalent to 0.6pg/kg body weight/day for TEQ, by calculation under consideration of 60kg for body weight. Although the daily intake of PCDDs/DFs via fish consumption in Korea was lower than that in Japan, this value was higher than that for the other countries. It is important to note that fish consumption is one of the main sources of PCDDs/DFs exposure in Korea.

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An analytical method was developed for GC/MS monitoring of 22 organochlorine pesticides in water using 47mm SDB-XC bond disks. The sample was passed through the disk under vacuum. The pesticides trapped in disk was extracted with acetone and hexane by ultrasonication. The extracted solution was concentrated to 5ml and cleaned up by Sep-Pak silica (690mg) and then analysed by GC/MS. The recoveries of pesticides from river water were in the range 80-104% except for HCB, Aldrin, and Endrin aldehyde. The recoveries were estimated by calibration standard solution (blank) which was prepared with n-hexane obtained through the extraction step using SDB-XC. The calibration standard solution (blank) was devised for the standard solution to compensate the matrices effect and to decrease rate of decomposition of DDT and Endrin in the injection port of GC.

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Unlike intact cells, cell extracts from a degrader of 4-chlorobenzoic acid (4-CBA), Acinetobacter sp. strain ST-1, could not dehalogenate 4-CBA. When both ATP and coenzyme A (CoA) were added, the extracts dehalogenated 4-CBA. When one of these cofactors was omitted, dehalogenation activity was not detected. The addition of the divalent metal ions Mg²⁺, Mn²⁺, Zn²⁺, or Co²⁺ increased the amount of reaction product from 2.5- to 3-fold; Fe²⁺ or Cu²⁺, however, inhibited dehalogenation. When ATP, CoA, and Mg²⁺ were added to the assay mixture, 4-CBA was converted hydrolytically to 4-hydroxybenzoic acid in 91% yield. Stoichiometric results suggested that CoA might function in the dehalogenation of 4-CBA by strain ST-1 as a real coenzyme that forms an intermediate of the CoA thioester of 4-CBA. The requirement for the molar ratio of ATP to 4-CBA to be 2 or more might be related to the energy requirement for the formation of the CoA thioester. These findings suggest that a process for the dehalogenation by strain ST-1 of 4-CBA and its analogs 4-bromobenzoic and 4-iodobenzoic acid involves the intermediate formation of a CoA thioester, activating hydrolytic dehalogenation.

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To establish a method of removing the residual chlorine, trihalomethane and 2-methylisoborneol in tap water, the pH and the concentration of the residual chlorine, trihalomethane and 2-methylisoborneol were measured during the heating, boiling and while maintaining a warm sample.
The pH of tap water became basic at temperatures near its boiling point. Under such conditions, the residual chlorine in the tap water is present as nonvolatile ClO^-. Therefore, the residual chlorine content in the tap water seems to decrease due to the reaction with the dissolved precursor organics in the tap water rather than by evaporation. When the tap water was heated to the boiling temperature, the content of trihalomethane increased due to the reaction of the residual chlorine with the precursor organics and decreased due to evaporation of the trihalomethane. The bubbling condition at the boiling point plays an important role in the removal of trihalomethane. Therefore, it was interesting to find the most effective bubbling method to remove the trihalomethane. The content of trihalomethane increased when residual chlorine was present in the solution, even after the trihalomethane in the tap water had been removed.
The boiling was also effective for removing the 2-methylisoborneol. The content of 2-methylisoborneol decreased with increasing boiling energy.

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Various air cleaners are available on the market to improve indoor air quality. In some cases, it was described in the catalog that they could remove not only particulate matter but also odorants. Then, to evaluate the performance of the air cleaner and to find more effective system for improving indoor air quality, 14 air cleaners on the market in Japan were tested of their performances in removing 21 typical indoor odorants. The test was carried out in the chamber that was made of stainless steel.
Some electrostatic precipitation system or filtration system fitted with effective deodorant filter could remove odorants significantly, but the others could not.
Removal rate of odorant depended on the odor substance, for example, dimethyl sulfide and acetaldehyde could not be removed readily by the all air cleaners. In some cases, odorous by-product was generated from some air cleaners because the oxidizer on the filter oxidized some odorants. After the air cleaner was used in the chamber of high odorants concentration, some odorant could be desorbed into relatively clean environment.

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This study was conducted to elucidate the distribution and the behavior of PCDDs and PCDFs in an ordinary environment in Japan. Soil, air and pigeon samples were taken from a typical suburban area and analyzed. PCDDs and PCDFs were detected from all samples. Total actual and TEQ concentrations was ranging 600-19, 000pg/g dry and 22-52pg TEQ/g dry in soil; 20-67pg/m³ and 0.37-0.91pg TEQ/m³ in air; and 990-2, 800pg/g tissue and 46-113pg TEQ/g tissue in pigeon fat tissue, respectively. Those values mean that this area is polluted at the average level of dioxins in suburban areas.
It was estimated that one of the major sources of dioxins in this area was “combustion process”, though the isomer profile of environmental sample did not completely correspond to that of combustion source. And a pesticide like CNP and/or PCP could be regarded as the other source by a statistical analysis on isomer profiles.

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Three principal pollutants in main stream of cigarette smoke were determined. Carbon monoxide concentration, indicater of incomplete burning, was minimum at the flow-rate of 0.3-0.4l/min. Each concentration of nitrogen oxides, carbon monoxide and total carbonyl compounds at the smoking flow-rate of 0.7l/min was higer than that at the flow-rate of 0.35l/min, respectively. An average removal rate of carbon monoxide and the total carbonyl compounds by a commercial pipe was 6 % and 14%, respectively.

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Batch hydride generation-electrically heated quartz furnace- atomic absorption spectrometry for the analysis of arsenic, selenium and antimony is presented. Pre-reduction of arsenic was verified by the secondary injection of sodium tetrahydroborate solution. “Memory” was considered to be caused by deposition of low volatile elements or oxides onto the quartz surface, which was intensive for antimony. This problem was solved by modifying the quartz furnace structure. Humidity control was needed for selenium analysis and was achieved by employing a large hydride generator, ice cooling of the sample and a silicon gas transfer tube. The present method was applied to sea water.

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