Tsuguo Mizoguchi

Gridded ammonia emission fluxes in Japan

In order to fully understand the acidification of precipitation, it is essential to determine ammonia emissions. Detailed gridded emission fluxes of NH3 have been compiled in Europe. In East Asia they have been determined on a national basis(Zhao and Wang, 1994). In Japan we have calculated NH3 emission fluxes on a 1° latitude × 1° longitude basis for livestock and the application of fertilizer. Livestock emission factors developed by W.A.H. Asman(Asman, 1992) for Europe were used 23.04 and 5.36 kg NH3/animal/yr. for cattle (dairy cows and beef), and pigs, respectively. Domestic animal population data was collected by prefecture and apportioned to grid cells based on the prefectural area in each grid cell. For fertilizer emissions, NH3 emission were calculated assuming a 10% ammonium nitrogen evaporation rate for ammonium sulfate, urea, and other nitrogen-containing fertilizers. Since prefectural fertilizer data were not available, total fertilizer usage for Japan was distributed to prefectures based on cultivated area. The maximum calculated NH3 emission fluxes for each of the three animal categories were as follows: Dairy cows, 4730 (Hokkaido), beef cattle, 4540 (Kyushu) and pigs, 3480 (Kanto) tonnes NH3/grid/yr. The total NH3 emissions due to livestock in Japan were 4.6, 6.0 and 4.4 × 104 tonnes NH3/yr. from dairy cows, beef cattle and pigs, respectively. The overall total NH3 emission from livestock and the application of fertilizer was 2.0 × 105 tonnes NH3/yr. The NH3 emission by Japan is small compared to those of most European countries.

Material damage caused by acidic air pollution in east Asia

Atmospheric and laboratory corrosion tests were carried out to assess the intensity of air pollution in East Asia. Qualitative and quantitative atmospheric corrosion was estimated from the damage caused to bronze, copper, steel, marble, cedar, cypress and urushi (Japanese lacquer) plates, exposed to outdoor and indoor airs in some cities of East Asia. Brochantite and cuprite were formed on copper at sites where the sulfur dioxide concentrations were high, and basic cupric nitrate and cuprite at sites where nitrogen dioxide concentrations were high. Gypsum was formed on marble pieces exposed to indoor air at all sites but was not found on pieces exposed to outdoor air. Numerous fine spots (0.2–0.3 mm in diameter) were observed on surfaces of urushi plates exposed at foggy cities such as Chongqing, China and Taejon, Korea. The effects of atmospheric and meteorological factors on the damage to copper and marble plates in several cities in East Asia were estimated using regression analysis. The results indicate that sulfur dioxide is the most destructive of materials especially in China and South Korea. In Japan copper plates may be damaged under natural conditions and by sea salt. Copper may also be damaged by surface deposition of sulfur and chlorine. Marble may be substantially degraded by gaseous sulfur dioxide but sulfate ions in rain had no effect. The analysis of air pollution from the point of view of material damage was very useful in evaluating and visualizing the intensity of air pollution in East Asia.

Isolation and some Properties of Bacteria that Degrade Polycyclic Aromatic Hydrocarbons

Abstract Four bacteria, which could grow on pyrene as the sole source of carbon, were isolated from soil from an urban area in Tokyo. One of them, strain H2-5, was a rod bacterium that was positive in gram staining and in acid-fast staining. The optimum growth temperature was 34-35°C, and the upper limit temperature for the growth was around 45°C. At a concentration of 1.3 μg/ml polycyclic aromatic hydrocarbon (PAH), H2-5 cells (45 μg dry weight/ml) grown on Tryptic Soy Broth made disappear 90% of pyrene in 12 hr, and Benzo(a)pyrene (BaP), Benz(a)-anthracene (BaA), and Benzo(ghi)perylene individually disappeared 60%, 25%, and 8%, respectively, in 3 days. PAHs in the extract by dichloromethane from airborne particles in approximately 5 m3 of air disappeared by the action of H2-5 as follows: pyrene, 100% in 3 days; BaA and BaP, 70% and 71%, respectively, in 4 days. Pyrene in tarry matter extracted from soil disappeared 88% in 4 days.

Regional Characteristics of Copper Corrosion Components in East Asia

Copper plates were exposed under shelters at 13 sampling sites in East Asia and their corrosion was analyzed. The corrosion products were first dissolved in water and then oxalic acid. Sulfate, nitrate and chloride in the solutions were measured by ion chromatography. The amounts of the three anions significantly differed depending on the atmospheric environment at the sites. Sulfate was a major part of the anions at Chongqing and Shanghai in China. Especially, at the urban sites in Japan, nitrate remarkably changed with the seasons, and often became the large anionic component in the summer. The amounts of chloride at most sites were at higher concentration levels compared with those at the rural sites in Japan. The anions in the copper corrosion must mainly reflect the impact of acid deposition.