Odor problems are generally, caused by many kinds of malodorous substances at low concentration, so it is almost impossible to analyse the whole components of the odor completely by any instrumental method, not only qualitatively but quantitatively. Supposing that the analytical data of constituents is obtained, the method to correlate the chemical data with the presence of odor theoretically has not been established at this time. So we can not evaluate the sensory perceived odor as the over-all characteristics of the odor from such data.
Because of the above reasons, there is a great demand for more persuasive odor evaluation system based on sensory measurement. Up to now, there are some criticisms about this method for the reasons that the result of sensory measurment has poor objectivism and there are some insolved problems, such as relations between odorants' concentration and odor intensity level and how to treat the threshold value or the effects of combined actions in complex odors. Therefor solving those problems is pressing needs now to develop the sensory evaluation system, and for this to get some basical informations is the purpose of this study.
The following compounds were used for odorants; Ethyl alcohol, iso-Amyl acetate Benzaldehyde, Methyl mercaptan, Methylamine, Dimethyl sulfide, Hydrogen sulfide and Ammonia. They were used singly and still more the mixtures of two components from the underlined substances as complex odors. From the results of sensory measurements, we obtained following conclusions;(1) Coefficient K varies with the character of odor and the valuse were as follows; irritating odor 3.3-5.0, rottening odor 2.5-3.7, non-irritating odor 2.1-3.3, aromatic smell 1.5-2.5.(2) The effect of combined actions in complex odors varies with the combination or the constitutional ratio of odorants.(3) The combined action occurs as the result of over-all function of alterations in both values of threshold and coefficient K.

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Percent of water soluble lead in the atmosphere, working environment and soil was investigated for the study of its effect on man. Present investigation shows airborne lead particles contained 30 to 60% of water soluble lead under immersion for 30 min at 40°C and their solubility of the atmospheric lead depended on the immersing time and temperature. After the sampling, the percentage of water soluble lead had tendency to decrease, particularly along a heavy traffic road area, because of change of the percentage. It is clear, that rainfall contributes to the reduction of the percentage of water soluble lead. In working environments, the ratio of soluble lead to total lead depended on lead compound used in respective places of work. The lead in the soil presented an almost less than 1% of soluble state. Finally, by using the ratio, lead absorption to human body may be more correctly estimated.

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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. The following are presented in this article (Report II).
(1) Correlation coefficients between concentrations of various pairs of elements were calculated. There were some groups of elements, whose concentrations showed strong correlation with one another.(For instance, Al, Sc, Ti, La, Sm, Th; K, Ca, Fe, Rb, Cs; Co, Ni, Zn, Cd, Pb)
(2) Enrichment factors defined by the following equation were calculated for various elements.
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where C (A) means concentration of element A and the elemental composition of average soil given by Bowen is adopted as standard. Our average values of (EF) _B agree with those previously reported by Harwell team. This suggests the chemical uniformity on global scale of airborne particulate material.
(3) Enrichment factor defined by the following equation was introduced.
_??_
where the elemental composition of average aerosol is adopted as standard.(EF) _g is considered to be more convenient for grasping the features of elemental composition of aerosol.
(4) Enrichment factor is a convenient measure for grasping the features of elemental composition of environmental material and has been often used in many environmental studies. But, it should be noted that enrichment factor can not be always a useful measure for estimating thedegree of elemental pollution.

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The Gaussian plume model in mesoscale area is treated and examined. The concentrations are simulated by the mesoscale plume model for the data of diffusion experiment at Tokyo area. The plume axis from a point source is estimated in the modified wind field. Wind field with weighted averaged initial values is modified to satisfy the equation of continuity by the fixed-station-velocity algorithm. From the results of the simulations, the mesoscale plume model is validated to be applicable to estimating ambient air pollutant concentrations.

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Gas chromatographic determination of monochlorodifluoromethane (CHC1F₂, F-22) in ambient air was studied. Air samples were collected to be pressurized in a stainless steel air sampling can. New measuring system combined with a back-flushing system using a two-layer precolumn was designed. The samples were transferred to a sample concentrating loop (cooled at-183°C) of the measuuring system and injected into an electron capture gas chromato graph. Moisture and components of a longer retention tithe than F-22 were eliminated by using the back-flushing system. Rapid determination of ppt level of F-22 in ambient air has been achieved with this, measuring system. This method was applied to measurement of atmospheric F-22 in Kitakyushu city, Japan. Average concentrations were 136 (max. 4200-min. 41), 58 (104-38) and 39 (51-29) ppt at commercial, residential and rural districts, respectively. Back ground level was shown to be 30 ppt.

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The total collection efficiency η _c , and the fractional collection efficiency η _x of a rotary flow cyclone (Drehströmungsentstauber; D. S. E.), for the steady and pulsating primary flow of the dust-laden air were measured.
The rotary flow cyclone made by transparent synthetic plastics had diameter D 1=150 mm and effective height H_i =466 mm.
Test dust was fly-ash having specific weight γ _p =2.14g/cm ³ and its residue cumulative distribution by weight could be expressed as R (x) w=100 exp {(-ln2) (x/12.44) ^1.97 } %. This dust was fed in the range of feed concentration C_i=4.6-5.2 g/m ³ by using a magnetic vibrator.
The pulsating air flow was produced by a rotating disc in inlet pipe of the primary flow. The revolution of the disc was ranged N=0-1500 rpm.
From these experimental results, the total collection efficiency η _c , more than 99% could be obtained in the range of flow rate Q ₂ /Q ₁ =1.0-1.9, in which Q ₁ and Q ₂ were the flow rates of the primary and secondary flow respectively. The experimental results of the fractional collection efficiency η _x could be described as η _x =1-exp {(-ln2) ( x/x _{c 50} ) ^m }. Here x _{c 50} was the cut-size corresponding to the particle diameter of η _x =0.5 (50%) and the exponent m gave the sharpness of the class of the classification. The minimum value of x _{c 50} foThe total collection efficiency η_c, and the fractional collection efficiency η_x of a rotary flow cyclone (Drehströmungsentstauber; D. S. E.), for the steady and pulsating primary flow of the dust-laden air were measured.
The rotary flow cyclone made by transparent synthetic plastics had diameter D1=150 mm and effective height H_i=466 mm.
Test dust was fly-ash having specific weight γ_p=2.14g/cm³ and its residue cumulative distribution by weight could be expressed as R (x) w=100 exp {(-ln2) (x/12.44) ^1.97} %. This dust was fed in the range of feed concentration C_i=4.6-5.2 g/m³ by using a magnetic vibrator.
The pulsating air flow was produced by a rotating disc in inlet pipe of the primary flow. The revolution of the disc was ranged N=0-1500 rpm.
From these experimental results, the total collection efficiency η_c, more than 99% could be obtained in the range of flow rate Q₂/Q₁=1.0-1.9, in which Q₁ and Q₂ were the flow rates of the primary and secondary flow respectively. The experimental results of the fractional collection efficiency η_x could be described as η_x=1-exp {(-ln2) (x/x_c50) ^m}. Here x_c50 was the cut-size corresponding to the particle diameter of η_x=0.5 (50%) and the exponent m gave the sharpness of the class of the classification. The minimum value of x_c50 for the steady air flow showed 0.48 μm and this value for the pulsating air flow showed 0.6-0.7μm.

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