In order to elucidate the behavior of sea salt particles in the ambient air, particularly for the interaction between sea salt particles and nitrogen dioxide, Cl^-, Na⁺ and NO₃^- in aerosols collected by Andersen sampler were measur ed in parallel with the measurements of NO₂ and HCl in air.
Cl^- loss from the aerosol mass was calculated only in the range of 2-7 μm particle size to avoid over-or underestimate caused by involving other sodium and chloride than sea salt particles. A significant correlation exists between the average NO₂ concentration and Cl^- loss, and the percent figure of Cl^- loss increases with the mole ratio of NO₂/NaCl and the relative humidity with good agreement to the experimental results by Robbins et al. The ratio of NO₃^-/Na⁺ in the aerosols is approximately the same as the stoichiometric proportion of NaNO₃ and also a significant correlation between the calculated HCl concentration estimated from the Cl^- loss and the actually measured HCl concentration was found.
These results show that NO₂ reacts with the moist sea salt particles to form gaseous HCI and NaNO3 in the ambient air.
HCl amount of 0.06-1.38μg/m³ and 0.00-0.37μg/m³ were estimated at Kobe station and Awaji station respectively in spring-summer time. The amount in winter was far less than that in spring-summer.

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To clarify the relationship of the bronchial asthma and sulfate aerosol (suspendedparticulates) as an air pollutant, effects of exposures to the aerosol which was produced by nebulization of ammonium sulfate solution on the experimental induction of asthmatic dyspnoea and on susceptibility of the respiratory tract in guinea pigs were investigated.
Two exposure groups (A-and B-group in Table 1) and their control group (C-group) were prepared. In the exposure groups, exposures to the aerosol (2 mg/m³ or 0.4 mg/m³) and to albumin spray (allergic sensitization) were carried out, and, in the control group, exposures to the albumin spray alone were carried out. Through the albumin spray, breathing curves (cf. Fig. 3) were continuously autorecorded to ascertain the intensity of asthmatic dyspnoea.
Results (cf. Fig. 5, 6 and Table 2) showed that number of animals with the stronger pattern of asthmatic dyspnoea were more in the groups exposed to the aerosol and albumin (A-and B-group) than the number in the control group (group-C).
Following all the exposure experiments, all groups were put to the acetylcholine susceptibility test. In the case of the aerosol exposure groups (A-and B-group), an increase in the susceptibilityof the respiratory tract could be observed (cf. Fig. 7 and Table 3). But, in the case of D-group which was exposed only to the aerosol without albumin sensitization, the increase of the susceptibility could not be observed (cf. Table 4).

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In order to obtain fundamental knowledges about sulfate aerosols, the field research was made in a coastal region where is distant from industrial pollution sources. The aerosol samples were collected by being fractionated using Andersen samplers during six days period, and they were analyzed for some elements, sulfate and ammonium ions. Sulfate was determined by the turbidimetry with 2-aminoperimidine, and ammonium was by the colorimetry of indophenol method. Trace elements with short-lived nuclides were analyzed by instrumental neutron activation analysis.
The mass-size distribution curve of total aerosols was the general bimodal pattern, although the concentration level was very low. Most of sulfate and ammonium salts were distributed in the fine particle range less than 2 μm in aerodynamic diameter, but sulfate had another peak, thought to be maritime origin, in the coarse particle range. Nevertheless, many fine sulfate particles that had been produced secondarily in the atmosphere were found in such a less-polluted coastal region.
The change of the sulfate concentrations obtained by the two-stage Andersen type sampler showed a correlation with the humidity. This may suggest us that the formation of sulfate aerosolsfrom sulfur dioxide could be related to a catalytic oxidation process in water drops.

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A study was directed toward establishing a new treatment process of odorous gas containing H₂S and (CH₃)₂S by activated sludge. In this experiment, two aeration tubes were used; the one contained activated sludge and the other water. The removal rate was estimated from the odorant concentration by gas chromatography at inlet and outlet of the tube. Each of odorants was removed at high rate of 99% by the sludge acclimated for above 2 days, but the removal rate by water reduced rapidly within few hours after feed initiation. The result of loading test showed that the feed rate of H₂S and (CH₃)₂S to obtain 99% removalwas below about 15 and 9g/kg-MLSS/day. Such performance was kept during the long term (about 50 days) experiment and a large quantity of sulfate was detected in the mixed liquor. When glucose was added to the aeration tube, the removal rate reduced immediately. This showed to be better to avoid the joint treatment ofodorous gas and waste water containing easily assimilable material such as glucose.

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Atmospheric ammonia gas and ammonium particles were separately collected on a two staged glass fiber filters. The first filter for ammonium collection was an usual glass fiber filter which waswashed with distilled water and dried at 120-130°C. The second one for ammonia collection was impregnated witha mixture of 3% boric acid and 25% glycerin solution. The blank of glass fiber filters impregnated with a mixture of the above solution was very low for ammonia, i.e. 0.06μg in a filter of 47mm in diameter.
The mean concentrations of ammonia and ammonium in air at Kawasaki, a polluted area were 7.6 and 2.3 μg/m³, and those at Sanriku, an unpolluted area 0.9 and 0.2μg/m³, respectively.
The concentrations of ammonia and ammonium at the polluted area were about 10 times higher than those at the unpolluted area. Ratios of concentration levels of ammonium to total ammonia in the atmosphere were 0.3 and 0.2 for the polluted and unpolluted areas, respectively. Ammonium salts in air at both areas were not correlated with relative humidity.

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About an automatic analyzer for atmospheric fluoride by the method of fluoride ion slective electrode, an analysis of static and dynamic characteristics and a few errors about measurement system (electrode, amplifier and recorder) was shown in comparison with one hour and three hours of sampling time. On the basis of these analysis, the instrumental error of two apparatus measured in an air polluted region was considered. As a result, it was appeared in a part of these data that the instrumental error can't explain only by the drift of the characteristics of measurement system. This suggests that sampling system (Teflon tube, filter and alkali coated spiral tube) sometimes lead to error.
For measurement of atmospheric fluoride under the level of 1 ppb, counterplans of improvement in accuracy which can be done easily are to set a compensation device for variation of temperature and to exchange the recorder which is linear about concentration for that which is linear about electrode potential.
Further, decrease of flow rate from setting value by drop of pressure in flow meter which lead to error about any measured value must be correct by change of span balue of recorder or others.

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