During every springtime, mineral dusts from Chinese arid areas can be sometimes monitored to be transported over Japan by the artificial satellite “Himawari”. This mineral dusts are called as Kosa aerosol. Studies for Kosa aerosol have been performed on various aspects in the atmospheric environmental field as well as geochemistry. Kosa aerosol has some interesting behaviors, for instance, the removal of acidic substances in the atmosphere. The neutralization effects of Kosa aerosol against the acid rain/deposition every year can be expected as much as 2-5kg equivalent/km² of strong acidic ions in Japan. In this paper, I present several environmental effects and natures of Kosa aerosol across the different reseach fields.

View full abstract

This paper reviews analytical methods, especially those involving sample preconcentration, for the determination of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in environmental water samples. In general, the analysis of these compounds is difficult, due to a combination of their generally low environmental levels and their physio-chemical properties e.g. low aqueous solubility and strong preference for particulate absorption. A large volume liquid liquid extraction and preconcentration system using an adsorbent resin e.g. XAD, C₁₈, or a polyurethane foam plug, to extract PCDD/PCDFs from water samples has been reported. To separate the“truly dissolved” PCDD/PCDFs from that adsorbed by particulate matter in large volume of water, continuous centrifugation or filtration is available. Since there is little published data in this area, it is necessary to develop a reliable and easy to use preconcentration system in order to collect reliable data on PCDD/DF concentrations in natural water and so elucidate the behaviour of these chemicals in the environment.

View full abstract

Destruction of PCDDs and PCDFs was investigated by using a dehalogenation reagent including a complex of polyethlene glycol, potassium hydroxide and dimethyl sulfoxide.
When reacted at 70°C, 2, 3, 7, 8-T₄CDD, the most highly toxic among PCDD and PCDF isomers, was very effectively decomposed, resulting into the degradation efficiency to be more than 99.9% for 1hour of the reaction time. A similar result was observed under the coexistence of fat impurities, exemplified by butter. In addition, when the dehalogenation method was adapted to O₈CDD or a purified fraction from waste incinerator fly ash including most of PCDD and PCDF isomers, similar degradation efficiency was also recognized.
In the case of O₈CDD degradation, 1, 2, 3, 4, 6, 7, 8-H₇CDD formed with a maximum yield of 0.28%. However, no other toxic tetra- through hexachlorinated isomers with chlorine atoms in 2, 3, 7 and 8 positions of their molecules generated.

View full abstract

The “Passive Gas Tube”, as a monitoring sampler for organic solvent fume in the working environment, was applied to the estimation of the amount of respiratory personal exposure to the volatile halogenated compounds (VOCs) .
Contaminations of VOCs in a commercial “Passive Gas Tube” were satisfactorily low level to detect VOCs in indoor and outdoor air. Atmospheric concentrations of VOCs measured by the“Passive Gas Tube” method, were highly correlated to the values by the active sampling method employing Carbosieve G as an adsorbent.
A study on the personal exposure and residential indoor air of VOCs was carried out using a probability sample of 14 homes from Sendai city. Mean concentrations of the personal exposure of five VOCs, i.e. chloroform, 1, 1, 1-trichloroethylene, carbon tetrachloride, trichloroethylene and tetrachloroethylene, were 0.234 ppb, 0.404 ppb, 0.080 ppb, 0.054 ppb and 0.070 ppb, respectively. Respiratory carcinogenic risks estimated from the data of personal exposure were 42×10^-6 for chloroform, 12×10^-6 for carbon tetrachloride, 5.2×10^-6 for tetrachloroethylene and 0.3×10^-6 for trichloroethylene.

View full abstract

Groundwater pollutions by chlorinated hydrocarbons have been frequently happened in Japan. In Fukuoka City, groundwater pollution by tetrachloroethylene (PCE) has been recently noted. PCE and various ions in this water were quantitatively analyzed, as well as the gas concentration of PCE in the soil and content of PCE at each depth of soil layer in attempt to find countermeasures. PCE in laundry water and soil was shown to be the source of pollution, and was assumed to permeate at locations of drying machines and sludge yards. High pollution by PCE was formed to be limited inside of narrow area surrounding the source.

View full abstract

To investigate the behavior and origins of atmospheric aldehydes, sampling of ambient air with 2, 4-dinitrophenylhydrazine-impregnated C₁₈ cartridge was performed at Saitama University, Urawa in the summer season, 1983 and ambient concentrations of aldehydes were determined by HPLC-UV method. Average concentrations of HCHO, CH₃CHO, C₃H₇CHO (identified tentatively), and C₆H₅CHO in daytime were ca. 5, 3, 5, and 0.4ppb (v/v), respectively. Regression analyses between each aldehyde's concentration and O_3-, CO_-, or NMHC-concentration gave the suggestive data that the origins of C₃H₇CHO (identified tentatively) and C₆H₅CHO were mainly secondary formation via. photochemical reaction, and those of HCHO and CH₃CHO consisted of both of direct emission by combustion of fossil fuels and secondary formation.

View full abstract

The Extracorponeal Shock Wave Lithotripy (ESWL) is well recognized to be one of the important clinical treatments for destruction of calculi in kidney and bladder by employing underwater shockwave focusing.However, the genotoxic effects of shock waves have not been clarified, yet. In this study, mutagenic and mutagenic modifying effects of shock waves were examined by using the Ames test.
Each bacterial tester strain (S. typhimurium TA98, TA100, TA97, TA102) and the mixture of tester strain and mutagen [cis-diaminedichloroplatinum (CDDP) ] were shot by shock waves. Mutagenic response of shock waves was not detected in any strains, with and without S9 mix, by the shot of shock waves with maximal pressure between 0 and 100 MPa.
Mutagenic and cytotoxic effects of CDDP were enhanced after shock wave shots on the mixture of tester strain and CDDP, indicating that shock waves may have indirect effects on the genotoxicity of chemicals.

View full abstract

A gas chromatography/mass spectrometric (GC/MS) procedure has been developed for the determination of ethylthiometon (ETM), which is a representative organophosphorus pesticide, in environmental samples. A liquid-liquid extraction method with dichloromethane (CH₂Cl₂) is applied to the separation of ETM residues in water samples. For sediment and fish samples, steam distillation is applied to the preseparation. The ETM in the distillate from a sediment sample is extracted with CH₂Cl₂. On the other hand, that from a fish sample is extracted with hexane and then is separated and purified by acetonitrile/hexane partitioning and alumina column chromatography. The extracts of water and sediment samples and the fraction of fish samples are concentrated and then determined by GC/MS, respectively. The detection limits are 0.12μg/l for water, 5.2μg/kg for sediment, and 5.6μg/kg for fish. The average recoveries of ETM from spiked water (0.8ppb) samples is 105%. Those from spiked sediment (40ppb) and fish (40ppb) samples are 90% and 85%, respectively. This method enables the reliable determination of ETM residues in environmental samples at ppb level.

View full abstract

A new large volume injection method (Dynamic Retention Gap Method: DRG ) for capillary gas chromatography was developed.
The retention gap consisted of a fused silica tube (2m×0.53mm i.d.) and the pre-column (0.5m×0. 53mm i.d.×0.5μm) was connected with the capillary column by a T-shape connector. A large volume of sample solution (100μl) vaporized in the injection port was rapidly introduced to the retention gap under large flow rate of carrier gas (20ml/min) . After the solvent was purged through the T-shape connector, purge vent was closed and the sample was introduced to the capirally column.
High linearity between injection volume and peak area of pesticide was observed with an in-jection volume of 1 to 100μl in the DRG method.
In the splitless method, some pesticides (DEP, captan, pyridafention, etc.) were decomposed in the injection port by heat. But in the DRG method, those pesticides were able to be analysed with little thermal decomposition, because the pesticide was rapidly introduced to the retention gap from the injection port under large flow rate of carrier gas.
In the GC/MS analysis, the residual water in the sample solution caused a lowering of the sensitivity. In the DRG method, the water was almost purged with solvent, then the contamination of the detector was less than the splitless method.

View full abstract

The analytical method of methomyl and oxamyl in environmental and biological samples has been developped by using the reverse phase high performance liquid chromatographic method equipped with post column fluorescence derivatization system.
Both compounds in water samples were extracted with dichloromethane and the extracts were cleaned up by 5% hydrous silicagel mini-column chromatography.
Both compound in sediment and fish samples were extracted with methanol and the extracts were diluted with 10% sodium chloride aqueous solution and washed with hexane. And then the extract was treated by the same operation on the water sample.
A 20μL aliquot containing aldicarb-sulf oxide was injected into a reverse phase HPLC column. The analytes were hydrolyzed with 0.05N sodium hydroxide at 85°C. Methylamine produced by hydrolysis of oxamyl, methomyl and aldicarb-sulfoxide reacted with o-phthalaldehyde (OPA) and 2-mercaptoethanol to form a highly fluorescent derivative which was detected by a fluorescence detector.
The present method was successfully applied to the analysis of methomyl and oxamyl in water, sediment and fish samples.

View full abstract

Annual fluctuations of pH and ion concentrations of soluble fraction in total deposition with a dust jar sampler were investigated during eight years (1984-1992) in Sendai city. The following results were acquired.
1) The acidification of soluble fraction in total deposition was observed at about 0.085 of pH in every year.
2) The soluble fraction between spring and summer was revealed to be slightly low pH in the comparison between autumn and winter.
3) As the results of factor analysis for pH and ion concentrations, the first factors were pH and Ca²⁺, the second one were Cl^- and Na⁺, and the third one was SO₄^2-.
4) It was suggested that the reason of reduce for calcium concentration of soluble fraction might be the decrease of road dust caused by the car with studded tire which was restricted to use recently. The annual fluctuation of calcium concentration were great enough to affect pH.

View full abstract

Determination of major and trace elements by ICP-AES has recently become to be a useful technics for various environmental samples. Up to now, almost ICP-AES instruments can be only given analytical results in a moment on a print paper or screen after were automatically computed. Therefore, some operators of ICP-AES in routine work have a mistaken conception which can be always obtained a good result by ICP-AES, or engage in it without information of spectroscopic interference of ICP-AES analysis and so on. This paper will describe about several fundamental and important properties of ICP-AES in routine analysis.

View full abstract

The residual concentrations of chlorinated organic compounds, including DDT, HCH, PCB, dioxins, and chlordane, found worldwide in human milk and published between 1980-1992, were abstracted from the literature and surveyed. Reported values are summarized as a tabular database.

View full abstract

A new movement on the application of supercritical fluid extraction to environmental analysis is briefly introduced. The extraction method is a successful alternative to liquid-solid extraction for sample preparation of many environmentally hazardous substances in solid matrices. Major factors for the extraction are pointed out referring some literatures.

View full abstract