Results of multielement analyses of airborne particulate samples collected at various residential areas in Japan were examined from the view point of characterizing the elemental air pollution, and it was attempted to find out measures which make it possible to grasp simply and clearly the features of elemental pollution. Measured elemental concentrations showed in general a log-normal distribution, and the geometric standard deviation, σ_g, is quite different from element to element. Geometric deviation, d_g (d_g=log (C/C)/log σ_g, where C and C are measured concentration and geometric mean concentration, respectively) and accumulation frequency were calculated for each element, and their usefulness in characterizing the elemental air pollution was evaluated.
Geometric deviation (or accumulation frequency) is considered to be a useful measure for grasping the features of elemental air pollution, because geometric deviation not only indicates the orientation of a measured concentration relative to the geometric mean concentration, but also decides the ranking of the measured concentration among all the measured concentrations.
For the purpose of comparing many measured concentrations of various elements with one another, geometric deviation is more convenient than “reference concentration”, which was introduced in Report I, especially because geometric deviation allows comparison of measured concentrations with one another regardless of element.

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The relation of emission rates of polynuclear aromatic hydrocarbons (PAH) from automobiles to their mileages was studied by test runs of 26 Japanese cars in ordinary city service. The mode of the change of PAH emission rate vs. mileage accumulation varied among the individual cars. However, for the groups of cars, a linear relation between the average' PAH emission rate and the average mileage was recognized at mileages above 20, 000 km. A linear relation between the average consumption rate of engine oil and the average mileage was also recognized at mileages above 20, 000km. That is, the high PAH emissions from used cars wit high mileage were mainly due to the high oil consumption.
It was found that the PAH emissions under used oil condition were higher than those under new oil condition. This was considered to be due to the increase in oil consumption rate by the lowering of oil viscosity and secondarily clue to the contribution of PAH accumulated in oil during running

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Influences of industrial particulate pollutants to the non-polluted atmospheric air was studied at Mizushima district and Niimi-shi sites in Okayama prefecture. Aerosol samples were collected by Andersen air samplers for a week, once a month over one year. Mizushima is a big industrial area with iron and steel industry, and Niimi is a small city situated in a valley of Chugoku Mountains. Collected samples were analyzed for 14 trace elements by instrumental neutron activation analysis and by atomic absorption spectrometry. A single standard method that uses manganese as an analytical standard material was applied for the determination of the elements, for the economy of labor and time in the preparation of neutron acivation analysis. The annual average size distributions of total aerosols at both sampling sites, industrial and remote areas, gave a well fitting in their bimodal patterns. The mass concentrations of aerosols were comparable at both sites, while the elemental concentrations were different for them. Especially, some elements that seem to be emitted by human activities appeared largely different in their concentrations. It is presumed that manganese and vanadium in coarse particles found in back-ground area mostly originated from soils, while they come from iron and other stationally sources in the industrial area. On the other hand, manganese and vanadium in fine particles (less than 2μm) in Niimi were thought to be transported from industrial area by atmospheric diffusion. This fact indicates that the fine particles are important in monitoring of air pollution and study of environmental science.

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During 168hr from 26 July to 2 August, 1977, simultaneous measurements of gaseous and particulate sulfur concentrations in the atmosphere were made at three observation sites which are located nearly in a straight line along the Yodo River. Distances between the sites are about 10 km. The variation of particulate sulfur concentration had a period of 24hr due to the alternation of sea and land breezes, and the variation patterns at the three sites were quite similar. The concentration peak appeared about one hour later at the leeward station than at the windward station in accordance with the movement of polluted air parcel. The average concentrations of particulate sulfur observed at the three sites were found to be nearly equal. Contrary to this, average concentrations of gaseous sulfur decreased from windward to leeward in the sea breeze time. It appears that the main variation of SO₂ gas concentration was similar to that of particulate sulfur concentration of one day period and this was superposed by a small variation which had also one day period and lagged in phase by 8 to 12hr. Using a simple transport and diffusion model, the conversion rate of SO₂ gas to sulfur particulate was calculated from the observational results taking the wind system into consideration. As expected, the conversion rate was high at the time of large insolation. The maximum of the observed values was about 20%/hr. Furthermore, a good correlation was found between the conversion rate and the oxidant concentration.

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The data for establishment of standards for allowable levels for short term exposure to air pollutants can be obtained through epidemiological studies and experimental exposure studies.
Human experimental exposure studies of the health effects of air pollutants can be accomplished at fixed concentration under well controlled conditions, focusing attention on physiological testing and evaluation of symptoms. Specifically, this report will involve tests to assess the reaction of respiratory airway to O₃, SO₂ and NO₂ alone or in combination at 0.15, 0.3 or 0.5ppm with rest or intermittent exercise for two hours. Effects of these air pollutants exposure on bronchial reactivity to acetylcholine are also studied. An experimental design based on these tests is described. Also some interesting results by using this design will be dealt with in this report.

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