Method for the sampling and analysis of phosphoric acid triesters including triethyl phosphate, triallyl phosphate, tributyl phosphate, tri (chloethyl) phosphate, tri (chloropropyl) phosphate, triamyl phosphate, tri (dichloropropyl) phosphate, and triphenyl phosphate in ambient air have been studied.
These compounds were collected on a glass fibier filter (7×9 inch) and XAD-7 resins (20g) with a high volume air sampler.
The ambient air sample was extracted in a Soxhlet extractor. After treatment of hydrochloric acid and sodium hydroxide, the sample was cleaned up by silicagel column chromatography, and determined by gas chromatography with a nitrogen-phosphorous detector using fused silica capillary column.
Collection efficiencies were obtained by spiking of standards on glass fiber filter and drawing through the ambient air at 700l/min for 24 hours.
It was observed that tri (dichloropropyl) phosphate and triphenyl phosphate were adsorbed on glass fiber fi lter and other phosphoric acid triesters were mainly adsorbed on XAD-7 resins. This method was applied to ambient air sample in Kitakyushu district. Triethyl phosphate, tributyl phosphate, tri (chloroethyl) phosphate, tri (chloropropyl) phosphate, tri (dichloropropyl) phosphate, triphenyl phosphate were identified by GC/MS-MF.
These compounds were detected approximately in the range of 2-5 ng/m³ in the ambient air.

View full abstract

Our previous papers presented a practical model to predict pollutant dispersion in a complex terrain. Thisstudy included dispersion experiments conducted in such region.
At first the field of wind flow in an area concerned is determined by modified potential flow model. Second the ground level concentration is calculated by a modified plume model.
This paper presents the effect of parameters in the plume dispersion model on the calculation in comparison with the observation of the experiments in Tochigi area.
In this model, the horizontal spread sigma;_y and vertical spread sigma;_z should be larger than those estimated from Pasquill-Gifford chart depending on atmospheric stability. In Tochigi area, sigma;_y and sigma;_z should be those corresponding to more unstable condition by 1-2 ranks. Furthermore sigma;_y should be diluted by about 3 times.
As the results, the effect of wind field model is more important than that of the dispersion model in view of the calculated concentration.

View full abstract

Diffusion of a tracer gas, from a street up to a distance 150 m away from the street in a residential area, is discussed.
A body source model is proposed as one of the ways in modeling the initial dispersion made by mechanical mixing of the gas in a street canyon.
When the width of the body source is assumed to be equal to that of the street and the height to be the mean height of the houses, the. predicted concentration agrees to a certain degree with that of the field observation.

View full abstract

In this paper we describe our studies on the asphalt in road dust in Niigata city. Road dust samples, namely deposit on the roadside, deposition and airborne particulate matter, were collected near a main street, Route 116, in town area. Additionally, deposition and airborne particulate matter samples were also collected in the suburbs as a reference site. Samples were collected from March 1983 through January 1984. Weighedsamples were Soxhlet extracted with (4/1) benzene/ethanol for 6 h. Asphalt was determined by use of gel permeation high performance liquid chromatography. Asphalt in road dust samples indicated rather high concentrations in winter and early spring, compared to other seasons in twon area. Especially, it was clearly observed in coarse particles. The amounts of asphalt in deposit on the roadside, deposition and airborne particulate matter were ca. 700, 50 and 6 times higher in March and April than the values of other months, respectively. In the suburbs, asphalt in road dust was lower than that of town area. The decrease of asphalt concentrations depending on the distance from the roadside was clearly observed in winter. These seems to be influenced by road dust which have been produced by motor vehicles with studded tires running on asphalt-paved roads in winter.

View full abstract

Particle-bound mercury (particulate mercury) in the air was collected on quartz fiber filters by high-volume air samplers and Andersen impactors at industrial, urban and rural regions in Niigata Prefecture. Mercury was determined by flameless atomic absorption spectrophotometry with a combustion-gold trapping-heat vaporization technique.
The concentration of particulate mercury showed a large regional variation. Fairly higher values and wider ranged temporal concentration variations were obtained in industrial and urban regions than the rural. In the rural region, the concentration was almost less than 0.05 ng/m³ and was lowest in winter.
From the size-distribution curves of particulate mercury and from the principal component analyses based on the correlations with the other components, it was estimated that there are two types of particulate mercury. One is formed by the adsorption of gaseous mercury released from the heating or combustion processes on the dust that emitted from the same source and it exists as a relatively small particle (less than 2 μm) in the air, the other is formed, mainly in rural regions, by the adsorption of gaseous mercury on the soil particle and it exists as a coarse particle (larger than 2 μm).

View full abstract

In order to evaluate the state of the environmental pollution in Chiba City, the correlation between air pollutants and metal concentrations in leaves of woody plants has been investigated. The elements of Zn, Pb, Cd, and Fe as pollutant indicators were extracted from the leaves (Viburnum awabuki, Euonymus japonica, Juniperus chiennsis, and Nerium indicum) by conventional method and their concentrations were determined. On the other hand, the dust in the atmosphere was collected by the high volume airsampler to measure the concentrations of metals. NO_x and SO₂ concentrations were automatically analyzed.
The following results were obtained:
1) Metal concentrations in the leaves of woody plants were widely changed in each plant, for example, at H sampling site where was near factory area, the average concentrations of Zn, Pb, Cd, and Fe in the leaves of Viburum awabuki were 41-56 μg/dry-g, 8.5-12.1 μg/dry-g, 0.79-0.92 μg/dry-g, 407-507 μg/dry-g and the concentrations of Zn, Pb, Cd, and Fe in the leaves of Euonymus japonica were 18-26 μg/dry-g, 9.8-17.5 μg/dry-g, 0.90-4.03 μg/dry-g, 490-583 μg/dry-g, respectively.
2) The leaves of woody plants had much Pb concentrations, when the Pb concentration in the leaves of woody plants was high at the site where concentrations of the air pollutants such as NO_x, SO₂ and dust were high.
3) The highest correlation coefficients of Pb-NO_x, Pb-SO₂, and Pb-dust were 0.87, 0.80, and 0.88, respectively.

View full abstract

Airborne particulates in Maebashi and Minato-ku Tokyo were collected on quartz-fiber filters using highvolume air samplers for 15 days in each month, Oct. 1983, Jan. Apr. and Jul. 1984. The mutagenicities of airborne particulates were evaluated by the pre-incubation method using Salmonella typhimurium TA100 and TA98 strains with and without S-9mix. The mutagenicities of airborne particulates in Maebashi were measured at Gunma Institute of Public Health, and those in Minato-ku were measured at National Institute of Public Health.
The mutagenicities of airborne particulates in Minato-ku were corrected with the factors which were calculated by measuring independently the same extracts of airborne particulates at two laboratories. The mutagenicities of airborne particulates in Minato-ku were higher than those in Maebashi for two strains. Seasonal variations of mutagenicities were observed. The mutagenicities in Minato-ku decreased in the order of winter>fall>spring>summer, whereas those in Maebashi decreased in the order to fall-spring>winter-summer. The difference between the seasonal variations in two areas was resulted that the seasonal wind might contribute to the mutagenicities in Maebashi.

View full abstract

A Chemical Oxidation state analysis of sulfur in airborne particulate collected at three representative sites in Beijing area, China from June 1982 to December 1983 has been performed. Particulate matters were collected on a dry and preweighed quartz fiber filter by means of a high volume air sampler for 24 hr once a week. A specimen sample cut as a disc from the filter was analyzed by a high resolution fluorescence X-ray spectrometer for the oxidation states. Calibration for quantification was made by using an oxygen combustion infrared analysis for total sulfur content.
As a result of peak separation of S Kα spectra, sulfur in airborne particulate was found to be in two states; S⁶⁺ and S^2-.
With regard to the total quantity of sulfur, the highest level was observed at Dongdan (urban site), and the lowest at Huairou (rural site). At Beixin'an (industrial site), the content of S⁶⁺ in total sulfur was the highest. The seasonal variations of total sulfur, S⁶⁺ and S^2- were almost similar at three sites and were observed wind velocity dependency. The effect of domestic heating with coal during winter-time caused a significant increase of S⁶⁺ and SO₂ especially at Dongdan, but not so much remarkably in total sulfur and S⁶⁺. This suggests that S^2- and SO₂ might originate from domestic noneffiicient coal combustion and that there might be another contributions such as industrial furnaces and air transportation for S⁶⁺.
At Huairou where S⁶⁺ content in particulate was highest, sulfur was inferred to be transported from distant sources along with a process of air oxidatton.

View full abstract