This paper presents techniques for determining the mean trajectory of plume emitted from a stack. Equations presented are not intended to provide a means for predicting day-to-day variations in plume trajectory for a given stack.
This investigation has been analyzed on the basis of the theory that there is a non-linear relation between plume rise and distance downwind on the Log-Log graph, not on the traditional linear relation “2/3 Power-Law.”
The equations for predicting plume trajectory are developed statistically and give good agreement with many field data which were observed not only in Japan, but in U.S.A. and Europe.

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This paper deals with techniques for estimating maximum rise of the bent-over plume. Information on plume rise is important in determining the concentrations of pollutant on the ground. Practical use of plume rise values may be made in connection with stack design, the use of urban air pollution mod ls, and in evaluating the hazards to a population complex.
This investigation is made on the objective assumption that the plume is levelled off when its vertical velocity is below 0.1 m/sec so that it can yield levelled-off point (x_max) and maximum plume rise (ΔH_max). The empirical formulas for estimating maximum plume rise are derived by multiple regression analysis and give good agreement with many field data.

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Mass-size distributions of atmospheric aerosols in Kitakyushu city were measured by use of Andersen sampler, and their trends in past three years (1974-1976) were investigated. The results showed that the distributions of aerosols are divided near 1-2μm into two groups, coarse and fine particles, regardless of sampling stations, seasons or years. Since differences in total aerosol concentration among sampling stations are due mainly to particles larger than 1μm (coarse particles), this particles are considered to begenerated artificially. For seasonal variations, the concentration of the coarse particles at the reference station also tends to increase in spring.
Therefore, different meteorological conditions and natural phenomena in addition to artificial sources may take part in an increase of the coarse particles. The division of the aerosols into two groups implies that the coarse and fine particles differ in their sources, formation mechanisms and removal processes.

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The contributions from fuel and engine oil to automotive exhaust emissions of polynyclear aromatic hydrocarbons (PAH) were studied. Only about 1 to 2% of PAH originally in gasoline survived the combustion process and was recovered from the exhaust, under the 10-mode operating condition. The amounts of PAH produced from one liter of ordinary gasoline in the engine were estimated as about follows: BaP 1 μg, BaA 5 μg, chrysene 5 μg, and pyrene 24 μg. PAH accumulation in engine oil was directly related to fuel PAH and oil mileage, and influenced the exhaust emissions of PAH. An increase in oil consumption caused an increase in PAH emission.
In comparatively new cars, the contributions from fuel and engine oil to exhaust PAH emission were comparable. As car mileage increased, PAH emission level increased and the contribution of PAH produced from pyrolysis of consumed oil became to occupy the larger part of the exhaust PAH emission.
The contribution from pyrolysis of consumed oil was, on the average, the most predominant factor of the emissions of BaP, BaA and chrysene from cars in ordinary city service, accounting for 76, 68 and 62% of their total emissions, respectively; the contributions from other factors decreased in the following order: gasoline PAH (11, 16 and 22% for BaP, BaA and chrysene, respectively), pyrolysis of gasoline (7, 13 an) (11%) and oil PAH (6, 3 and 5%). For emission of pyrene from these cars, on the average, original amount present in gasoline was the most predominant factor, with the contribution ratio of 46%; the contributions from other factors decreased in the order of pyrolysis of consumed oil (31%), pyrene in oil (12%) and pyrolysis of gasoline (11%).

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In an attempt to deodorize malodor from sewage or night soil treatment plants, removal of the two malodorous components, ammonia and trimethylamine was tried by absorptive exidation with hypochlorites. In a packed tower (packed height: 60 cm), gas containing ammonia (2-10 ppm) and trimethylamine (1-5 ppm) was absorbed and oxidized with sodium hypochlorite solution, whereby the overall mass transfer coefficient was examined to determine the optimum treatment conditions. The following were proved to be optimum for a room temperature treatment; superficial gas velocity: 1.7 m/s, liquid/gas ratio: 2, pH of the absorptive solution: around 7, concentration of sodium hypochlorite: 1.5×10^-3 mol/l.
An actual plant test under these conditions showed that ammonia and trimethylamine in real exhaust gas from a night soil treatment plant could be removed almost completely.

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Aldehydes can be determined as their imidazolidine derivatives formed by reaction of aldehydes with N, N'-diphenylethylenediamine (DPED). This investigation was developed for the gas chromatographic determination of aldehydes in the atmosphere as their imidazolidine derivatives by sampling into absorption bottle.
For imidazolidine derivatives derived from formaldehyde, acetaldehyde, propionaldehyde and butyraldehyde, the stability in absorption solution and extraction solvent, the recovery, and the trapping efficiency of these aldehydes were examined. Phosphoric acid solution of DPED as absorption solutionand trichlormethane as extraction solvent were used. Good results were obtained for formaldehyde and acetaldehyde.
The merit of the proposed method is as follows: a large volume of air is not required, because the detectable sensibility for formaldehyde and acetaldehyde was good, both about 0.2 ng, and the effect of blank of absorption solution was not found.
The lower limits of determination (sampling air: 30 1, condensed volume of extractant: 1 ml) were 0.5 ppb for formaldehyde and 0.3 ppb for acetaldehyde.
Formaldehyde concentrations in the air of road tunnel were determined by the present method, showing a good agreement with the results obtained by the 4-amino-3-hydrazino-5-mercapto-1, 2, 4-triazole method.
The gas chromatographic method presented above can especially be used for the determination of formaldehyde in the atmosphere.

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As absorbing reagents serving as color developing reagent, N, N'-diethyl-p-phenylenediamine (DPD), 3, 3'-dimethylnaphthidine (DMN) and 2, 2'-adino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) were examined. The most suitable pH and composition in each solution is as follows: DPD: PH 6.3, 0.2 mg/ml, DMN: 3, 6μg/ml, ABTS: 2.5, 0.1 mg/ml. The collecting vessel used in DPD and DMN method was not a sinteredglass bubbler but a midget impinger. In ABTS method, sample air must be drawn with a sintered glass bubbler (No.1, pore size: 0.1-0.12 mm). Maximum drawing rate to obtain collection efficiency near 100% with 10 nal of the solution (depth: 22 mm) and observed chlorine recoveries from standard gas flow were as follows: DPD: 1.5 liter/min, 96%; DMN: 0.8, 97; ABTS: 1.5, 100. ABTS method had large colorstability and little interference of SO₂, DMN method had low blank value and little interference of NO₂ and O₃. These two methods were better than usual o-tolidine method. The Cl₂ concentration which may be determined with sample size of 1 liter and coefficient of variance in the determination were as follows: DMN: 0.22-2 ppm, 3.2%; ABTS: 0.13-3, 2.8.

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Five plants which are very sensitive to photochemical oxidants were exposed to various concentrations of ozone or PAN (peroxyacetyl nitrate) for several different periods of time; spinach, radish, taro, peanut, and petunia for ozone and petunia for PAN were tested in a controlled atmospheric chamber.
As a result, the injury degrees of the five plants for ozone or PAN were logarithmically dependent upon both concentration and exposure duration. In this view, the interrelationships between concentration and exposure duration and plant injury could be analyzed using the mathematical model which was derived from our previous ozone exposure experiment on morning glory: S=m ln C+ n ln t+K, where S is the plant injury degree, C is ozone or PAN concentration in ppm, t is the exposure duration in hours, and m, n, and K are constants. To determine the constants for these plants, multiple linear regression calculations were made by using the mean values of injury degrees. Because the values of m and n for each plant were different, as obtained by the calcul ations, the degree of injury was not in a simple linear relation to ozone or PAN dosage (C×t). Therefore, when the conventional dosage (C×t) is substituted by the powered dosage of Cm/n×t, the injury degree can be expressed as a function of one variable which combines concentration and duration. The values of min for the five plants ranged from 1.61 to 2.43 for ozone, while the value for petunia was 1.33 for PAN.
Spinach was the most sensitive plant for ozone of the five plants and morning glory; the injury threshold concentrations for ozone were obtained as 0.128, 0.065, and 0.035 ppm for 1, 3, and 8 hours, respectively. For petunia the threshold values for PAN were 0.032, 0.014, and 0.007 ppm for 1, 3, and 8 hours, respectively.

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Measurements of total aluminum and water-soluble coarse (>2μm) sodium concentrations in the aerosols of Nagoya urban area were made, from September 1976 to April 1979 and the contributions of soil and sea salt to aerosols in urban air was described. The average background concentration of soil particles in the three seasons except spring was about 15 μg/m³. In the spring, yellow sand dusts called Kasa were transported from North China to Japan, so that the concentration increased to about 30 μg/m³. On the other hand, the average background concentration of sea salt particles was about 2-3 μg/m³. It was estimated that the environmental impact from primary natural sources was about 25% of the total aerosols in the Nagoya urban area, and especially in spring was about 40%.

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