The studies of isotope ratios analysis by inductively coupled plasma mass spectrometry (ICP-MS) on environmental and biological samples are reviewed. The precision of isotope ratio measurement by quadrupole type ICP-MS is reported to be in the range of 0.1-1% relative standard deviation in most of the literatures. Lead isotope ratios are most extensively analyzed for environmental and biological samples because their naturally occurring variations are much larger than the precision of ICP-MS measurement. Analysis of relative significance of various sources of lead in atmosphere and that of long-range transport of pollutant lead, and identification of lead source (s) of poisoned children are the main targets of researches, indicating significant contribution of isotope ratio analysis by ICP-MS to environmental chemistry field.
Osmium isotopic analysis is also carried out by ICP-MS for determination of age and origin of geological materials. Further improvement of the precision of isotope ratio measurement with ICP-multi-collector MS and -high-resolution MS will contribute to clarification of environmental dynamics of elements.

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Two simple methods were developed for determination of pesticides in air. To determine pesticides for short-term monitoring, quartz-fiber filter (Toyo Pullflex 2500 Qatup) and activated carbon-fiber filter (Toyobo KF Paper P-175) shaped into a circular form with a diameter of 47 mm, were used for sample collection (filter method) . This method was developed for determination of bensulide, butamifos, captan, chlorothalonil, diazinon, fenitrothion, fenobucarb, malathion, napropamide, pendimetalin, propyzamide, pyridaphenthion, shimazin and tetrachlorvinphos. Air was sampled with the quartz-fiber filter and the activated carbon-fiber filter, or with the two activated carbon-fiber filters at 10-20l·min^-1for 1-12 h using an automated sequential air sampler, Tokyo Dylec 10-line Global Sampler GS-IOD. Each sampled filter was extracted ultrasonically with 3 ml of an extraction solvent for 10 min. The extracts were filtered and concentrated for GC or GC/MS determination. The filter method was applied to investigate variations of aerial concentrations of pesticides after aerial application and ground application. Pesticide concentrations were mainly dependent upon elapsed time after the applications, air temperature, wind direction and distance from the applied area.
For long-term monitoring of pesticides, a glass collection tube (115 mm length, 18 mm i.d. with 3 mm i.d. at both edges) packed with 0.5 g of quartz-fiber wool and 5 g of activated carbon, Calgon BPL of 0.25-0.42 mm in diameter, supported by a small plug of quartz-fiber wool was used (tube method) . This method was developed to determine buprofezin, edifenphos, ethofenprox, fenitrothion, fenobucarb, fenthion, flutolanil, fthalide, malathion, pencycuron, phenthoate, pyridaphenthion, tetrachlorvinphos and tricyclazole. Air was sampled for 7 days with the collection tube set at a flow rate of 0.1 to 0.2 l·min^-1. The pesticides collected were eluted from the collection tube first with 100 ml of acetone and then with 100 ml of toluene-ethanol (4: 1 v/v) at a flow rate of 0.5 ml·min^-1. The combined eluates were concentrated for GC or GC MS determination. Annual concentration variations of pesticides were elucidated by using the tube method. Pesticides were detecable during May to October, while they were not detected during November through next April.
To determine pesticides deposited on the ground, two typical sampling materials, a cellulose filter paper (Toyo No.5A) and the filter coated with glycerin, were evaluated. The result shows that these materials have insufficient collection efficiencies for fenitrothion, malathion and tetrachlorvinphos. Therefore, an alternative method using an activated carbon-fiber filter (a 5 cm×6 cm Toyobo KF Paper P-175) was developed for the purpose. The pesticides investigated were fenitrothion, fenobucarb, malathion and tetrachlorvinphos. Deposited pesticides were collected on the filter, and extracted ultrasonically with 3 ml of benzene-ethanol (4: 1 v/v) for 10 min followed by centrifugation at 3000 rpm for 10 min and analyzed by GC. Moreover, a determination method using the card-for-deposit-survey (CDS) was also developed for the purpose. Three blue CDSs of 33cm²were used for pesticide collection. Diameters and numbers of droplet strains on each CDS were counted using a microscope at 25-fold magnification. Sum of the droplet strain area multiplied by 0.336 gave the volume of pesticide deposited, and amount of pesticide was calculated as the product of the applied pesticide concentration and the volume of pesticide deposited.

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A membrane extraction disk (Empore^TMExtraction Disks SDB-XC) was evaluated as a solid phase extraction (SPE) medium for the isolation and the trace enrichment of pesticides from water samples.
Reagent water, tap water and natural waters spiked with 32 pesticides at the concentration of 0.005mg/l were extracted with the SPE disk prior to the GC/MS determination of the pesticides. For most of the pesticides, the percent recoveries from reagent water were in the range from 90 to 110% with the coefficient of variation below 5% on the elution by dichloromethane, acetone, ethyl acetate or methyl t-butyl ether. The time needed to extract 200ml sample was about 1 minute for the reagent water and the tap water. In the case of natural waters, the extraction time were ranged 1-12min depending on the suspended solids in the samples. The extraction time over 10 minutes could be fairly reduced by putting filter aids on the top of the disk.

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The authors have developed an analytical method for determining organophosphoric acid triesters (OPEs), tributyl phosphate (TBP), tris (2-chloroethyl) phosphate (TCEP), diethyl-p-nitrophenyl phosphate, tris (2-butoxyethyl) phosphate and tricresyl phosphate (TCP) in water, sediments and fish. OPEs in a water sample were extracted with dichloromethane; the extract was dehydrated and concentrated to 1ml.
OPEs in a sediment and fish were extracted with acetonitrile. The extract was concentrated and then diluted with 5% sodium chloride aqueous solution. After the aquaous solution was ex-tracted with dichloromethane, the extract was concentrated. In order to remove substances which interfer instrumental analyses, florisil column chromatography and activated carbon column chromatography was performed for sediment and fish samples. After the internal standards were added to the final concentrate, quantitative analyses were performed by GC/MS-SIM.
Since GC/MS-SIM is a highly sensitive and selective technique, the developed method could not only simplify complicated pretreatment which was used in the former methods using GC-FPD, but also provide very low detection limits: 0.0095-0.12μg/L for water, 0.34-14μg/kg for sediments and 1.6-58μg/kg for fish. The method was applied to the analysis of real samples. TBP, TCEP, and TCP were detected at ppb levels. This method is useful to elucidate the fates and the concentration levels of OPEs in the aquatic environment.

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The uptakes of five volatile chlorinated hydrocarbons (VCHs) into respiratory organs were evaluated at similar concentrations to those in environmental air. Trichloroethylene (TRI), 1, 1, 1-trichloroethane (111TRI), tetrachloroethylene (PERC), tetrachloromethane (TCM), and chloroform (CHLO), in n-hexane solution were vaporized in an office (68m³) . Then, the room air as inhaled air and exhaled air from a volunteer were simultaneously collected with 2L and 1L of Tedlar Bags, respectively, at several time-intervals. All samples were directly analyzed by GC/ECD. The concentration of each of VCHs in both inhaled air and exhaled air was measured as a function of the sampling time, and the time -average uptake of each of VCHs into respiratory organs was evaluated: TRI, 50.6±5.8%; CHLO, 47.7±5.9%; PERC, 38.6±10.8%; TCM, 24.8±10.4%; 111TRI, 19.8±7.7%.

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In order to develope sensitive and automatic determination method of the β-galactosidase activity in umu-test, a flow-injection fluorometric system has been applied. In this system, β-galactosidase induced by umu-test in the Salmonella typhimurium strain TA1535/pSK1002 was reacted with 4-methylumbellif eryl-β-D-galactopyranoside (4MUG) as a substrate. The activity was measured as the fluoresence intensity of 4-methylumbellif eron which was the reaction product. Detectability of this method was confirmed by measurement of the dose response relationship using typical 4 mutagens: 4-nitroquinoline-N-oxide (4NQ0), benzo (a) pyrene (BaP), 2-aminoanthracene (2AA) and 2- [2-furyl] -3- [5-vitro-2-furyl] acrylamide (AF2) .

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Mutagenicity of 15 diaminodiphenylmethane and related compounds used or synthesized as epoxy resin hardner, many of which were 4, 4'-diamino-diphenyl derivatives, were examined by Ames preincubation assay using Salmonella typhimurium TA98 and TA100 in both absence and presence of metabolic activation system (S9 mix) . 8 compounds showed the mutagenicity in the presence of S9 mix. Mutagenic activities decreased according to the increase of the molecular weight. It was suggested that the mutagenicity of aromatic amines synthesized as epoxy resin hardner were affected by the type and the position of substituent and by their formula weight.

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Some of the topics reported in SETAC (Society of Environmental Toxicology and Chemistry) 2nd World Congress held at Vancouver, Canada, between Nov.5 and 9, 1995, were described briefly.

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Recent studies on volatile aromatic hydrocarbons in exhaust and air from Sweden are intro-duced. The aromatic hydrocarbons which were focused on here are benzene, toluene, ethylben-zene and xylenes (BTEXs) . Proportions (percentile weight) of BTEXs in exhaust from domestic wood burning, a cat-cracking refinery and vehicles are reported. Concentrations of BTEXs are studied on indoor and outdoor air. These results are very important for evaluating impact of the BTEXs on atmospheric environment and human health by inhalation.

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