Is air pollution health effect potentiated when we do exercise in polluted atmosphere, and if so, what mechanisms are responsible? This review tries to provide scientifically based answers to the above practical question.
There are evidences showing that oral breathing starts to participate in the pulmonary ventilation at minute ventilation of about 35-40l/min, and pollutant gases like ozone, when inhaled, are much less readily uptaken by the oral passage than the nasal one. Thus, exercise ventilation has a distinguishing characteristic that is an increased participation of oral breathing in additian to an increase in inhaled air volume, and will cause the penetration of a larger volume of pollutant gases into the deeper airways and lungs than expected on the basis of nasal breathing. On the other hand, there are many reports with human volunteers which demonstrated the increase in functional effects when they were subjected to continuous or intermittent exercise during the controlled ozone exposure. Similar, though not many, reports are also available in animal experiments.

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A method for the determination of micro-amounts of fluoride in ambient air was developed, in which fluoride ion was converted to trimethylfluorosilane (TMFS) by trimethylchlorosilane (TMCS) and determined by head space gas chromatography.
Fluoride in ambient air was collected on the membrane filter for fluoride particulates and on the alkali filter paper impregnated with 1% Na2CO3 solution for gaseous fluoride at a rate of 20l/min for 1-2 h. The sample on each filter paper was extracted with 20ml of distilled water on water bath. The sample solution was filtered off and diluted to 25ml with distilled water.
The sample solution containing up to 0.3 μg of fluoride was taken into a 50-m1 vial. Then 20ml of HCI was added and diluted to 50 ml with distilled water. The vial was sealed quickly after adding 1ml of HCI saturated with TMCS. The mixture was allowed to stand for 30 min at 30°C. The head space gas of TMFS in the vial was sampled and was in jected into gas chromatograph equipped with FID. A good linear relationship was obtained between peak height of TMFS and concentration over the range 0-3 μg of fluoride. The relative standard deviation for 10 results at the 0.1 μg of fluoride level was 2.4%. The method was simple and sensitive, and also relatively free from interferences.
Satisfactory results were obtained when the method was applied to ambient air. The detection limit of fluoride was 0.01 μg/m³.

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A photochemical air pollution model was developed in order to support considering pollution control strategies. Diffusion model consists of two-layer box model, and advection is estimated from distribution of wind velocities calculated by MATHEW model, one of inter-and extra-polation models. As photochemical reaction model, RS-32 model containing 12 reactions was adopted, in which hydrocarbons are classified into three reactivity classes.
Verification of the model wascarried out as follows. Ob ject area which is 46 km by 37 km was set in Harima area, and climatological data, environmental monitoring data and emission data in summer 1980 were used. The results show that, even in two-day simulation, calculated values of ozone concentration moderately coordinate with observed ones.

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Validity test of the micro-forward mutation assay using Salmonella typhimurium strain TM677 was carried out using benzene-ethanol extracts from airborne particulates as test materials. Sensitivity of this assay in the presence and absence of S-9mix was five to ten times higher than the pre-incubation method, a modified method of Ames's original method, using Salmonella typhimurium strains TA98 and TA100. This means that the virtual sensitivity of the micro-forward mutation assay is ten times or more higher than the pre-incubation method, because two or more strains are necessary in the latter method. Repeatability of the micro-forward mutation assay was nearly same with that of the pre-incubation method. That is, the coefficient of variation of mutagenic frequency of the particulate extracts was about 10%.
This forward mutation assay was applied to airborne particulates indoors, and proved to be able to measure easily the mutagenic activity of the extracts from particulates collected by only 30m³-air sampling. Some indoor pollutants, especially ones collected in a room in which cigarette smoking was done, showed higher mutagenic activity than that of outdoor sample. Particle size dependency of the mutagenic activity could also measure by this method using air particulates collected by only 90m³-air sampling with an Andersen/Low Pressure Impactor. The highest mutagenic activity was found in the particulates of 0.52-0.33μm in size. These results suggest strongly that the micro-forward mutation assay is a useful tool for survey mutagenicity of indoor environment.

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In order to clarify the harmful effects of diesel exhaust particles to the luug, transtracheal instillation of diesel particles (totally 10mg) into the rat's lungs were performed. For comparison activated carbon partilces and solvent were also instilled to the other group. Non-treated control was also prepared. Eighteen months to 30 months after instillation rats were killed and examined. Pathologically many epithelial hyplasias and lung tumors, including carcinoma, and leukemias were seen in diesel particle group. Statistically significant percentages of lung cancer were seen in the diesel particle group comparing with activated carbon group and solvent group. No epithelial hyperplasia or lung tumor was seen in the non-treated control group. These data mean diesel particles are harmful (especially carcinogenicity) to the rat's lung.

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The quasi-stational reactive diffusion model of NO and NO₂ has been be applied to long-term average concentration.
Some diffusion models with conversion of NO to NO₂ by chemical reactions have been presented. Among them, the quasi-stational model by Kimura (1978) can be combine with any diffusion model and it does not include emprical parameter, because it is a pure theoretical model. However, the model gives conversion rate only for short-term average concentration, and we need background concentrations of NO₂ and 0₃, which are sometimes difficult to be obtained. In this' report, these short points are improved.
It will be shown that the background concentrations can be estimated from observed long-term average concetration at a few monitoring stations in a large city, and the estimated values do not strongly denpend on the place of the monitoring station. A convertion formura for long-term average concentrations will be introduced. In this formula, we need a new parameter which corresponds to variation coefficient of short-term concentrations. The formula can convert NO_X concentration into NO₂ concentration with high accuracy without complex calculation.
The convertion rate for anual average concentration can be approximated by a line with slight curvature in a logarithmic chart, and it agrees well with the regression lines of the corventional statistical models. This model is not only as simpl as a statistical model, but also it theoreticall suports the statistical models.

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The characteristics of air pollution under land and sea breeze were investigated numerically using the transport model with the effects of photochemical reaction and dry deposition. The simulation for the wind fi eld of the land and sea breeze was perfomed, and the simulation for the concentration of the pollutants emitted into the simulated land and sea breeze. As the photochemical reactions model, we adopted the Ikeda's simplified model II, which includes 18 chemical reaction.
The time at which maximum values of 0₃ concentration appear delays as going inland for the influence of the sea breeze. The maximum values of NO concentration are shown at about 0800 JST. During daytime, O₃ is formed principally by the photochemical cycle involving NO, NO₂. During the nighttime, there are no chemical source for NO, and its concentration is depleted by the reaaction with O₃. By comparing the pollutants concentrations of the simulated results with those of the observational results, it is shown that simulated results in this study are in qualitative agreement with observational ones.

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An application of ion chromatography exclusion (ICE-method) to the determination of carboxylic acid concentration in rain water was examined.
It was found that the ICE-method was suitable for rapid and simultaneous determination of five carboxylic acids (formic acid, acetic acid, propionic acid, succinic acid and glutaric acid). But, as the ICE-method was unsuitable for the determination of oxalic acid and malonic acid for poor separation, these acid were carried out by normal ion chromatography.
The carboxylic acids in rain water were completely decomposed for several days at room temperature, but, these were stable for three months or above when the samples were spiked with CHCl₃ or HgCl₂.
The method established in this study was applied to the analysis of rain water collected in Nara City in a period from June, 1985 to May, 1986. The annual mean concentration of the carboxylic acids turned out to be as follows: 0.181μg, /ml for formic acid, 0.112 for acetic acid, 0.004 for propionic acid, 0.018 for oxalic acid, 0.007 for malonic acid, 0.010 for succinic acid and 0.005 for glutaric acid.
The annual mean percentage of concentration of hydrogen-ion concentration yield from the carboxylic acids to the hydrogen-ion concentration in rain water was established to be 3.89% for formic acid, 0.59% for acetic acid and 4. 94% for the total carboxylic acids.

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