The physiological and biochemical characteristics of ozone-resistant cultivars ofspinach (Spinacia oleracea L.) were compared with those of sensitive cultivars.
Comparison of stomatal densities between ozone-sensitive (Ujo and Japanese Prickly) and ozone-resistant (Viroflay and King of Denmark) cultivars revealed no relationship between ozone resistance and stomatal density.
Stomatal diffusion resistances of these four cultivars increased during ozone exposure (0.15 ppm, 2.5 hr), and the two resistant cultivars had slightly higher stomatal diffusion resistancevalues than the two sensitive cultivars. But judging from the small varietal differences, stomatal diffusion resistance does not seem to be a main factor in ozone resistance.
changes in activities of enzymes participating in the detoxication of active oxygen were studied in four spinach cultivars. During ozone exposure (0. 15 ppm, 3 hr), activity of glutathione reductase increased; activities of superoxide dismutase and catalase did not change significantly; activities of ascorbate peroxidase and dehydroascorbate reductase decreased. Guaiacol peroxidase activity increased later, as leaf injury became apparent.
Glutathione reductase activity in spinach leaves increased immediately after the start of ozone exposure in resistant cultivars and increased 1 or 2 hr later in sensitive cultivars. The decrease in ascorbate peroxidase and dehydroascorbate reductase activities in leaves began sooner in sensitive cultivars than in resistant cultivars. These differences in activities of enzymes participating in the detoxication of active oxygen therefore appear to be related to ozone resistance.

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The efiects of prolonged (5 hr/day, 10 days) low-concentration (0.025 ± 0.005 ppm) ozone exposure on enzyme activities and levels of ascorbic acid and total glutathione in spinach (Spinacia oleracea L.) leaves were compared in ozone-sensitive (Ujo and Japanese Prickly) and ozone-resistant (Viroflay and King of Denmark) cultivars.
Exposure to ozone at 0.025 ± 0.005 ppm for 5 hr daily for 10 days reduced the activities of superoxide dismutase, ascorbate peroxidase, glutathione reductase, and catalase in leaves of sensitive cultivars; it greatly elevated the activities of glutathione reductase and catalase and slightly elevated the activity of superoxide dismutase in leaves of resistant cultivars. Ascorbic acid levels decreased in leaves of sensitive cultivars but not of resistant cultivars. Total glutathione rose markedly in leaves of one resistant cultivar (King of Denmark) but decreased in leaves of a sensitive cultivar (Ujo).
The rise in total glutathione and the activation of glutathione reductase and catalase in resistant cultivars treated with low-concentration ozone appear from this study to be adaptive mechanisms to ozone toxicity.

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When the long-range transport occurs, a large amount of airborne aerosols, in particular, organic aerosols are produced, together with photochemical oxidants. In this paper behavior of dicarboxylic acids as the representative of the organic aerosols was investigated. Field observation was madeduring 26-31 July 1986 as a cooperative research program on the regional air pollution. Observation sites were selected along the longrange transport route but far inland from large emission source area, at Takasakiand Karuizawa.
The dicarboxylic acids and other organic matters in the form of airborne aerosol were collected on a quarz fiber filter using a high-volume air sampler for every 3 hours. After the filter was extracted with dichloromethane and subsequently with methanol, the extracted organic matters were analyzed by GC-FID equipped with a capillary column.
Concentrations of dicarboxylic acids increased in the daytime, in particular, when the transported air mass was arrived at the sampling sites, and decreased at night. These diurnal variations were similar to that of ozone.
Fraction of the dicarboxylic acids formed in the daytime were estimated to be more than 70% at both sites and thus high concentration dicarboxylic acids in the daytime were concluded to be produced photochemically during the long range transport of the polluted air mass.

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Road dust, collected from the road of a main street in Sendai City, benzo (a) pyrene [B (a) p] and a mixture of those substances were instilled into the lungs of male Syrian golden hamsters by intratracheal instillations once a week for 15 weeks. The total doses given were 30 mg of road dust, 3.75 mg of B (a) p, or 30 mg of road dust plus 3.75 mg of B (a) p. As a control, hamsters were treated with the vehicle, phosphate buffer solution. During the total life span, one lung tumor was seen in the 29 hamsters in the B (a) p group. There were no tumors in the respiratory tract in the other groups. Concerning histopathological findings of the lungs, the incidence of pneumocyte hyperplasia in the dust group was significantly higher than that in the control group.
From these results, although we could not observe any tumorigenicity or cocarcinogenic effect of road dust, it seems that road dust produced weak but positive damage to the lungs of hamsters.

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In order to estimate NO_x emission from heavy duty diesel vehicle, on board type-measurement system (OBTMS) was investigated. The outline of OBT-MS is as follows: NO_x concentration and inlet air flow was measured and recorded continuously at running, and NOx emission was calculated by computer after running. By comparing with CVS method, it became clear that OBT-MS can be applied to estimation of NO_x emission under practical road conditions.
As the results of running survey by OBT-MS by heavy duty diesel truck (Displacement 6.5 l, DI engine) on arterial road in Tokyo,
(1) The traffic characteristics was not much different from other large cities in Japan.
(2) Regression li ne between NO_x emission factor (Q_nox) and over all speed (V_t) was described similarly with the NO_x emission factor previously reported.
(3) Running speed (V_r) was adequate for evaluation of NO_x emission rate (G_nox). Average G_nox at idling and deceleration mode was about 8mg/s, and constant mode was about 20mg/s, acceleration mode was about 46 mg/s. G_nox of constant and acceleration modes increased in proportion to V_r as follows:
·acceleration; G_nox=1.13V_r+7.75
·constant; G_nox= 0.40V_r+7.75
(4) Contribution to NO_x emission throughout a test run depend on time ratio of idling mode under about 10km/h in V_t. But, over about 10 km/h in V_t, NO_x emission rate of acceleration mode increase in proportion to V_r, then contribution of acceleration mode to NO_x emission was the majority.

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For selecting indicator plants of photochemical oxidants among crop species, a field survey on the foliar injuries was conducted for potato, peanut and taro cultivars. The survey indicated ‘Waseshiro’, ‘Chibahandachi’ and ‘Dodare’ for potato, peanut and taro, respectively, were the most sensitive cultivars among the ones examined. Since the sensitive cultivars are widely grown in China Prefecture, they can be used as the indicator plants of photochemical oxidants.

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A simple and sensitive measurement method of ammonia in offensive odors by large amount of suction-gas detector tube was evaluated in terms of basic efficiency, such as sensitivity and precision, and its practical application to various offensive odors was carried out.
The instruments for attaining the large amount of suction were a diaphragm pump, flow meter and wet-type gas meter. Ammonia was measured at a flow rate of 150ml/min for 5 min. The ammonia concentrations examined were in the 1-5 ppm range, which is the regulation standard on the boundary line of sites laiddown in the Japanese Offensive Odor Control Law.
The satisfactory results were obtained with regard to sensitivity, precision, discolour tone in the indicator, stability of mean discoloured length, effects of amines and acids, and the time required for this. method. Also, this method (A) was compared with the official method (B; absorption with boric acid solution and analysis using indophenol) by measuring 39 samples with offensive odor obtained from typical ammonia sources such as poultry farm.(the correlation coefficient=0.985, A/B =1.05±0.17 (range: 0.64-1.50))
From these results, it may be concluded that the present method is as practical as the official method for the initial screening tests.

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Through the pursuit of the materialistic life which has resulted from technological advances, the sources of air pollution have multiplied and diversified. The three sources that have most accelerated air pollution are over population, rapid urbanization and industrialization.
The SO₂ and TSP levels of the larger cities were slightly over the environmental standard but the states of CO, HC and NO_x pollution remain beneath the standard indicated.
Countermeasures were taken to correct these problems and they can be summarized in the following three steps:
The first step taken to decrease the SO₂ concentration was to recommend the transfer of the use of coal briquets to the cleaner oil fuels as well as providing low sulfur oils through the installation of desulfurization facilities and expanding the LNG supply within the Seoul metropolitan area. The transfer is not yet complete but the government now provides low sulfur fuels to the Seoul community.
The second step taken was the reduction of dust particles through stricter supervision and the incentive of financial support for dust control facilities from the government.
The third and last step was the reduction of oxidants through the installation of catalytic converters and the resultant use of unleaded gas with these converters in all automobiles produced since January 1988. Such as the already existant problems of acid rain and asbestos as well as the future problems of heavy metals in the air and the depletion of the ozone layer.
However, many air pollution problems still exist. To cope with all of these problems we must have international as well as national cooperation for technological development and information.

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