Atmospheric halocarbons were collected by means of the dryfreeze trapping method in the altitude range from 8700m to 11100m over Northern Pacific Ocean and Northern American Area using a jet air liner, Boeing 747 cargoplane, flying from Tokyo to New York via Anchorage in March 1980. “Bleed air” from the compressors of jet engines was passed through the trap tubing, packed with the porous polymer PORAPAK Q, which was cooled at a temperature of dry ice, -78°C. Collected air samples were analysed by Electron Capture Gas Chromatography and Gas Chromatograph-Mass Spectrometry.
The materials determined at our laboratory were F-11 (CCI₃F), F-12 (CCI₂F₂), CCI₄, CHCI₃, C₂H₃CI₃, C₂CI₄ and also C₂HCI₃.
The sample collection system used here was very compact in volume and made operations safe, so that it was quite suitable for the work on a aircraft in which there are many limitations.
Comparing the results with other reports, concentrations of F-11, F-12 and CCI₄ are lower than those of European reports.
And the concentrations of other chlorocarbons, except trichloroethane, might be athigh level although there are few report to be compared.

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In order to reduce sulfuric acid mist formed by photochemical reactions in the ambient air, it is necessary to clarify the effects of primary pollutants and other conditions.
In this paper, some irradiation experiments of the HC+NO_x+SO₂ system were carried out on the formation of sulfuric acid mist by using the Mechanical Engineering Laboratory Smog Chamber. The mist formed in the chamber was collected on the millipore fiber filter of 47 mm in diameter, and the filter was impregnated with 80% isopropyl alcohol solution. And then, the extracted sulfate ion was determined by balium chloranilate method.
The experimental results are follows:
(1) The formation of sulfuric acid mist increased in proportion to the initial concentration of SO₂.
(2) The initial concentration of NO_x had no effect on the formation of sulfuric acid mist.
(3) Irradiation light intensity did not affect on the formation of sulfuric acid mist.
(4) The formation of sulfuric acid mist was nearly equal at both 20 and 25°C. However, the mist increased slightly at 30°C with respect to 20 and 25°C.
(5) Relative humidity had highly active effect rather than temperature. The higherthe humidity, the higher the mist concentration. In the case of changing relative humidity from 20% below to 50-60%, the mist concentrations increased 146% at 20°C, 136% at 25°C and 167% at 30°C, respectively.
(6) The formation of sulfuric acid mist was related to the sort of hydrocarbon. Paraffins were totally not active on the formation of the mist. Among olefins, especially, 2-Methyl-2-Butene had a high activity on the formation of the mist. Aromatics were generally active on the formation of the mist.

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Mutagenic activity was tested for 10 organic solvent-extracts of airborne particulates in order to find the extracting solvent most suitable for a routine mutagenicity survey of air pollutants. Organic matter in airborne particulates was extracted by the soxhlet extraction method. Solvent used were acetonitrile, methanol, benzene, benzene-ethanol (4: 1, v/v), acetone, ethylacetate, ethanol, cyclohexane, ethylether and n-hexane, respectively. Mutagenic activities of these extracts were measured by the pre-incubation method using Salmonella typhimurium TA100 and TA98 strains with and without S-9 mix.
The mutagenic activities of these extracts were in the following order; acetonitrile, benzene-ethanol, acetone, ethylacetate, ethanol, methanol, benzene, cyclohexane, ethylether and n-hexane. The eight solvent extracts other than ethylether and n-hexane extracts showed positive mutagenic activity for the both strains mentioned above with and without S-9 mix. The ethylether and n-hexane extracts gave negative mutagenic activity for TA98 strain in the test condition without S-9 mix, although these extracts gave positive response for the other test conditions. The mutagenic activity of the acetonitrile extract was very strong and was statistically significant for the activities of the other solvent extracts. The activities of benzene-ethanol and acetone extracts were also significantly higher than those of cyclohexane, ethylether and n-hexane extracts. However, there was no significant difference among the activities of benzene-ethanol, acetone, ethylacetate, ethanol, methanol and benzene extracts.
Stability of mutagens during the soxhlet extraction for 8 hr was also tested usingwell known 6 mutagens (benzo (a) pyrene, quinoline, 8-hydroxyquinoline, 2-aminofluorene, 2-nitrofluorene and 2-acethylaminofluorene) and organic matter extracted from airborne particulates by an ultrasonic extraction method. Mutagenic activity of 2-acethylaminofluorene decreased by the refluxing in three kinds of spectral grade solvents of acetonitrile, acetone and ethylacetate. This decrease was caused by the reaction of 2-acethylaminofluorene with impurities in these solvents. It was also proved that mutagenic activity of organic matter in airborne particulates was strongly enhanced by refluxing it in acetonitrile for 8 hr, and slightly decreased in methanol. But, benzeneethanol gave no effect on the mutagenic activities of these compounds. Benzene-ethanol has also been used as an extracting solvent in a chemical analysis of organic substances such as polynuclear aromatic hydrocarbons in airborne particulates. From these results mentioned above, it was able to be concluded that benzene-ethanol (4: 1, v/v) was the most suitable solvent for a routine mutagenic survey as well as chemical analysis of organic matter in airborne particulates.

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Concerning the analyses of SO₄^2- and NO₃^- on filters on which airborne particulates were collected, the measurement conditions of SO₄^2- and NO₃^- on filters and the influences of SO₂ and NO₂ at low concentration on the analytical value were investigated in order to find out the suitable filter for the airborne particulates sampling. The filters used were glass fiber filter (G. F), quartz fiber filter (Q. F), teflon binding glass fiber filter (T. B), and teflon coated glass fiber filter (T. C). To extract SO₄^2- and NO₃^- on filters completely, more than ten minutes' work on ultrasonics was needed. Amounts of the ions showed no serious errors by the portions cut from the filters. Anions on filters were stable for 30 days when stored in a freezer under -20°C.
The amount of SO₄^2- produced by exposuring SO₂ to filters was in the order of G. F >> Q. F > T. B ≈ T. C. As to NO₃-amount produced by exposure of NO₂, differences among the filters were not appreciably observed. Q. F showed slightly high value of SO₄^2- in airborne particulates but it fits to the monitoring because of its high collection efficiency and low pressure drop.
T. C showed the least influence of SO₂ and NO₂ on the amount of SO₄^2- and NO₃^- as well as high collection efficiency, but drastic pressure drop by clogging. It was suggested that T. C was suitable for accurate determination of anions in airborne particulates samples collected in a short time.

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A chemiluminescent light has been obtained from the reaction of ozone with an oil coated paper filter. The light emission has a gentle spectrum in the wavelength of 400-550 nm, and its intensity is generally strong for lubrication oil such as automotive engine oil. As an application of this phenomenon, a proto-type ozone monitoring system has been made. This ozone monitor is composed of a reaction vessel with an optical window, a detection and sample gas flow systems. The sample gas containing ozone is introduced into the vessel through a glass nozzle, and sprayed on surface of the reactive paper filter. The light generated in the vessel is emitted through the window, and detected by a photomultiplier tube. Its output signals per 10 seconds are continuously measured by a photon counter. To obtain a high and steady sensitivity to ozone concentration, this apparatus was typically operated under the conditions of a sample flow rate and a pressure in the vessel, 1.2 l/min, -300mmHg, respectively.
To standard ozone, the limit of sensitivity represented 0.001 ppm (v/v). The light response varied linearly with ozone concentration over the range of 0-0.19 ppm, its change to 0.15 ppm ozone was within ±3% for three months. To atmospheric ozone, the measuring accuracy resulted in nearly 0.01 ppm. However, daily ozone concentrations by this ozone minitor were almost in agreement with the results from a conventional chemiluminescence ozone meter using ethylene. Therefore, it can be considered that this new method is the quite satisfactory for its practical use as an atmospheric ozone monitor. In addition, the ozone monitoring system can be used so safely that ozone concentrations are determined without employing combustible ethylene.

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Separation behavior of polynuclear aromatic hydrocarbons (PAH) in a dual band thin-layer chromatography (TLC) and in a high performance liquid chromatography (HPLC) was studied in order to develop a new analytical method which could also supply the separated PAH samples for a mutation assay or a physico-chemical measurement. PAH was separated on the TLC plate [kieselguhr layer (5×20 cm)-(26% acetylated cellulose+cellulose Avicel SF) (95: 5 w/w) layer (15×20 cm)] with methanol-ether-water (4: 4: 1 v/v) as a developer. Development was continued until the solvent front reach the 10 cm mark on the latter layer of the TLC plate. Developing time was about 60 min. Separation behavior of PAH in HPLC was studied in the following two chromato-systems; Nucleosil 7C18 column (35 mm×4.6 mm, i.d. +250 mm×4.6 mm i.d.)-acetonitrile-water (6: 4 -9: 1 v/v) system, and Nucleosil 5NO₂ column (35 mm×4.6 mm i.d. +250 mm×4.6 mm i.d.)-n-hexanebenzene (5: 5 -95: 5 v/v) system.
Separation pattern of PAH was fairly good as compared with that in an ordinary TLC and several carcinogens were easily separated each other. Relative Rf values of PAH were stable and highly reproducible in this TLC. In HPLC, retention time of PAH decreased with the rise of column temperature. There was a linear relation between the logarithm of the retention time and the reciprocal of absolute temperature of the column. Retention time of PAH decreased also logarithmically with the increment of acetonitrile content of the acetonitrilewater mobil phase. Linear relation was observed among the carbon number of PAH and the logarithms oftheir retention times.
Most of 48 PAHs tested could easily separated each other by the combination use of the TLC and the HPLC using Nucleosil 7C₁₈ column.
PAH which were unable to separate each other in this method could be easily identified by spectrofluorometry. It was proved that this method was useful for analyzing PAH in airborne particulates and also for mutagenicity assay of the separated PAH.

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A simple and rapid measurement method of light intensity for photoirradiation experiment in laboratory was investigated. It is an indirect method using commercially available silicon photocell (SPC) which is able to detect very weak light, and is utilizing linear relationship between output of SPC and rate constant of NO₂ photolysis (κ₁). Correlation coefficients between the output of SPC and each of the rate constants of NO₂ photolyses in N₂ using a batch reactor (Tedlar bag) (κ₁ (N₂)) and in air (N₂: O₂=80: 20) using a flow reactor (quartz tube) (κ₁ (air)) were 0.99₇ and 0.99₈, respectively. This method allows continuous monitoring of light intensity and detection of the decay of light intensity during photoirradiation experiment.

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Cyclone dust collector (cyclone) is one of the most favorite equipments which are used for separation of solidparticles from gas. In spite of the extremely simple construction, cyclones have a high centrifugal effect. Therefore cyclones which are combined with another equipments are applied as the measures for dust separation on the air pollution in city planning.
Here the author described the the mechanical characteristics for the performances and the constructions of Tseries cyclone dust collectors which were developed and investigated by CSVZ works in Czechoslovakia. The report of T-series cyclones were based upon a book of “Industrial Separators For Gas Cleaning” by OTAKAR ŠTORCH (Elsevier, 1979). On the strength of the detailed data of T-series cyclones for the constructions, for the fractional collection efficiencies, for the total collection efficiencies, for the driving conditions and for the standard test dusts, the author calculated the Reynold's number Rcy, inerita parameter Φ and the diameters X_D1 of the of the mechanical equilibrium particles at the cyclone wall. From those calculated results, total collection efficiencies η _c of Tseries cyclones could be settled by the two parameters X_C50/X_R50 and X_D1/X_R50, where X_C50 was a diameter of cut-size and X_R50 was a representative diameter which was corresponding to 50% of the cumulative distribution curves of test dust. And then the coefficient ξ _d of pressure drop Δp_c could be settled by the inertia parameter φ for T-series cyclones.
T-series cyclones have very fine separation parformances and various kinds of constructions which can be combined as multicyclones. The author believes that those Tseries cyclones are very profitable and suggestive for considering cyclone dust collectors in our country.

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