Changes in the prevalence of respiratory symptoms in a selected population were analyzed for the period of 10 years to investigate the relationship between the onset of chronic bronchitis and the level of atmospheric pollution.
Kashima, the survey area, was a typical rural district before 1970. Since 1970, when petro-chemical complexes, iron works and power stations started the operation, certain levels of air pollutants (SO₂ 0.018 ppm, NO₂ 0.015 ppm, particulate 0.07-0.02mg/m³, annual averages) have always been detected. A series of interview surveys using the BMRC's Questionnaire were performed in 1966, 1969, 1973 and 1976. The subjects, both sexes, 40-59 yrs in age and 800 in number, were selected from the inhabitants living for long in Kashima and Oono (unpolluted area). To hold the comparability of the results, the special attention was paid to follow the standardized procedure for training of interviewers, assigning the subjects to interviewers and setting the situation for interview.
Time-trend of prevalence could not been observed for the 10 year-period, nor the difference between Kashima and Oono. These negative findings in contrast to the definite change in pollutants levels above mentioned may lead to the denial of the relationship between the prevalence of respiratory symptoms and the levels of pollutants. A further long-term observation is desirable to be conclusive of following possibilities implied by the present study.
1. A longer exposure (more than 5 years) may be necessary to develop chronic bronchitis. And a still longer exposure may be necessary, when the subjects had not been exposed to the coal combustion pollutants.
2. Increases in the prevalence of individual symptoms may precede the increase in the prevalence of combined symptoms of “persistent cough and phlegm”.
3. A time-trend estimated by only 4 data points could be consistent.

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An analytical technique for the simultaneous measurements of the atmospheric concentrations of SO₂ gas and sulfur absorbed by aerosol particles has been developed. Aerosol particles are collected on membrane filter and at the same time SO₂ gas is captured on alkali impregnated filter. The sulfur content in each filter is measured by an energy dispersive X-ray fluorescence spectrometer consisting of a Si (Li) semi-conductor detector connected to a multi-channel pulse height analyzer and an excitation source of ⁵⁵Fe. Two methods are acceptable for the determination of the sulfur content in impregnated filter by X-ray fluorescence analysis. In the first method X-ray fluorescence analysis is made after the collected sulfur has diffused and distributed uniformly enough throughout filter, and in the second method X-ray fluorescence analysis has to be finished before the diffusion of the collected sulfur becomes appreciable. It was confirmed that the method developed can be applied to practical observation with sufficientreliability.

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In this paper, the atmospheric dispersion model of emissions from an offshore airport is discussed and the calculated results are compared with those obtained from the tracer dispersion experiments.
The model proposed in this study is a combined one, puff and plume model. The dispersion of aircraft emissions is simulated by puff model and emissions from non-aircraft airport activity is plume model.
Exhaust gas of operating aircraft is replaced by the series of puffs which are released from the sources located along the path of aircraft with constant interval. The strength of a puff is determined by the emission rate of engine and interval length of sources. Puffs are flowed by wind and diffused by atmospheric turbulence. The concentration of pollutant gas at a receptor point is obtained from the integration of concentrations owing to all puffs affected to this point.
The accuracy of puff model is evaluated using the results of tracer experiments carried out at the proposed sites of Sin Kansai International Airport. From the comparisons of calculated and observed results, it is cleared that the choice of diffusion factors is very important to get a good agreement and the model is valid not only for steady meteorological condition, but also unsteady condition, such as the interaction of sea and land breezes.

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Recently, epiphytic bryophytes and lichens became to used as an indicator of atmospheric pollution, because they are apparently more sensitive to air pollutants than other plants.
In the present investigation, the epiphytic bryophyte and lichen vegetation on trees were investigated in the Eastern Harima region of Hyogo Prefecture, and the correlation between air pollutants and the epiphytic vegetation was analysed by using multiple regression analysis.
It is seemed that the atmospheric pollution based on the Index of Atmospheric Purity (IAP values) which was calculated from the frequency, coverage, density and fertility of epiphytic species (De Sloover and LeBlanc, 1968) is generally correlated with the SO₂ isopleths with exception of some areas in the investigated region.
Multiple regression analysis was attempted to make clear the correlation between the IAP values and such influential factors as concentration of SO₂, concentration of soluble matters in rain water and dryness of habitation for epiphytic vegetation. As the consequence, it was found that concentration of SO₂ and soluble matters in rain water have combined effects on them, the later was more influential than the former.
On account of the facts mentioned of above, it was considered that the IAP values were an useful combined pollution index for the total air pollution.

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The meaning of parameters σ_y and σ_z which appear in conventional diffusion formula is considered. Though σ_y is equal to standard deviation which can be calculated from concentration distribution, σ_z cannot be directly derived from the distribution. So the meaning of σ_z, is diffusion parmeter, but not statistical quantity such as standard deviation. The Turner charts show σ_y and σ_z against travelling time t, but the Pasquill charts show these parameters against leeward distance x. Comparing both charts, Turner's and Pasquill's, the Turner charts correspond to the Pasquill ones when wind speed is 6m/s. From the above consideration on the meaning of parameters, the Turner charts which are independent of wind speed have no general significance, and when the wind speed is u, the values of the parameters should be multiplied by √u/6.

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The distributions of fluorocarbons (CCl₂F₂ and CCL₃F) in the urban air over the Kitakyushu district were investigated.
Average concentrations were found to be 0.46 and 0.34 ppb at commercial and residential districts for CCl₂F₂, and, 0.20 and 0.16 ppb at commercial and residential districts for CCl₃F, respectively. The average ratio of CCl₂F₂/CCl₃F was 2.3 and 2.2 at commercial and residential districts, respectively. There was no significant difference between the ratios of CCl₂F₂/CCl₃F of the two districts.
Also, the diurnal variations of concentration of the fluorocarbons were investigated. Sometimes, high concentrations of CCl₂F₂ and CCl₃F were recorded, which were probably due to release of the propellant of aerosol products and/or temporary release of the refrigerant of containers.

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