The purpose of this study was to estimate quantitatively the effects of ozone on several kinds of plant species in the Kanto area with damage functions of the photochemical O_xidants (O_x) concentration measured by air quality monitoring stations and annual agricultural production. The damage to eight kinds of agricultural products, rice (paddy), wheat, barley, soybean, turnip, tomato, spinach, and lettuce, and Japanese cedar were estimated. Firstly, the average ozone concentrations during the growing period of the plants and the ozone dose were calculated with the O_x concentration measured at air quality monitoring stations in the Kanto area for each of the 45 sec (long.)×30 sec (lat.) (about 1km × 1km) grid points in the study region. In the calculation, we assumed that O_x equals ozone. For the agricultural products, relative yield loss at each grid point was estimated with damage functions and the ozone concentration. And then, the decrease of annual production was estimated by multiplying relative yield loss with annual production. Finally, the economic loss caused by the decrease of annual production was estimated based on production cost or wholesale prices. On the other hand, for Japanese cedar the decrease of the dry weight per tree was only estimated with damage functions and the ozone dose. The result of this study shows that many kinds of plants in the Kanto area are seriously effected by ozone.
The decrease of annual production of the agricultural products and the dry weight of Japanese cedar by ozone effect were detected. It was found that the total economic loss of the agricultural products results in almost 21 billion yen a year. In general, the ozone sensitivity of vegetables is higher than that of cereals. Relative yield loss for lettuce is almost 8%, which is the highest of all the vegetables. On the other hand, relative yield loss for rice is almost 3.5%, which is comparatively low, but decrease of annual production is very large because of the large amount of annual production for rice. Consequently, the economic loss for rice reaches 14 billion yen a year, which account for 68% of total economic loss of the agricultural products. As for Japanese cedar, the decrease of the dry weight per tree in the northern Kanto area was estimated to be around 1.5kg.

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Metal dissolution in the combination of acid rain (acid fog or pure water fog) and the atmosphere (gas and aerosol, or gas alone) was carried out under three conditions, and dissolution characteristics of metals and aspects of ion species on surfaces were examined. The corrosion contribution of Fe ion on an carbon steel plate was 74% for artificial acid mist, 25% for aerosol, and 1% for gas. The contribution of Al ion on an aluminum alloy plate was 75% for artificial acid fog, 20% for aerosol, and 1% for gas. The contributions of Cu ion on a bronze plate and copper plate were 55 and 51% for artificial acid fog, 13 and 22% for aerosol, and 32 and 27% for gas, respectively. The ratio of gas increased considerably in the corrosion contribution of Cu ion on bronze and copper plates. As for other ions, it was estimated that the corrosion dissolution mechanism was very complex. The concentration of ion species increased in rain, after the species contacted each metal boar, except H⁺ ion which showed a concentration below the blank value. Many ions showed significant differences between blank water and rain on metal plates. These results show that some chemical reactions and the adsorption response proceed in parallel with the dissolution of metal ions.

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Recently in Japan, local air pollution by nitrogen oxides (NOR) emitted from automobiles has attracted considerable attention. Furthermore, noise pollution at heavy traffic roadsides has also attracted attension.Therefore, soundproof walls are constructed by local self-governing bodies for the prevention of noise pollution.
Therefore, we investigated NOR removal by oxidation with a new catalyst composed of waste polystyrene foam and cement. Nitrogen dioxide (NO₂), normally desorbed as an intermediate of NO oxidation with TiO₂ photocatalyst, was not detected with nitrogen monoxide (NO) oxidation using this catalyst, because of NO₂ adsorption on the porous surface structure of cement. Removal ratio of NO was greatly depended on the contact frequency of NO to the catalyst surface. Therefore, only the thin layer of TiO₂ coated on acoustic material contributed to NO oxidation, because the removal ratio of NO was independent of change of TiO₂ weight coated on the acoustic material. 2.37 × 10^-4mol (7.11 × 10^-3g) of NOR/a cyllindrical catalyst of i.d. 50mm and length 50mm could be removed with this catalyst, until activity of the catalyst declines from 100% to 70%. The high activity of NOR oxidation was not effected by change of the ratio of NO₂ to NOR and SO₂ addition to experimental gas. Environmental load would be reduced with the manufacture of this catalyst, because waste polystyrene foam is recycled.

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From April 2001 to April 2002, a total of 102 dew and 9 frost samples were collected using a Teflon sheet at a rural site in western Niigata-City, in the costal area along the Sea of Japan. Dry deposition to the dry Teflon sheet, fog and/or drizzle to the Teflon sheet, and atmospheric deposition using filtrating bulk samples were also collected for a comparison of ionic composition and flux measurement. The volume weighed mean pHs of dew, frost and fog (and/or drizzle) were 5.9, 5.8 and 3.7, respectively; whereas it was 4.7 for atmospheric deposition. The total water flux from dew and frost per year was 15.0 mm, correspondsing to nearly 1% of precipitation. In the following series of ions, the number in parentheses gives the percent of the yearly flux of the ion in dew and frost compared to atmospheric deposition for the same period: H⁺ (0.1), NH₄⁺ (5.8), Na⁺ (0.7), K⁺ (2.6), nss-Ca²⁺ (2.9), Mg²⁺ (0.8), nss-SO₄²⁺ (1.5), NO₃^- (1.8), Cl^- (0.7). The mean concentrations of NH₄⁺, K⁺ and organic acid (HCOOH and CH₃000H) in dew were higher than those in frost; whereas sea-salt components were higher in frost. Depositions accompanied by dew and frost were strongly affected by dry deposition, however, there were large differences between dew and dry deposition of H⁺, HCOOH and NO₂^-. Accordingly, HCOOH and NO₂^-are important ion species for the acidification of dew.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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