Effects of Acid Deposition on Urushi Lacquer in East Asia

Urushi (Japanese lacquer) plates were exposed to indoor air in 7 cities in East Asia from summer 1995 through winter 1997. The plates, collected every 3 months, were optically observed by using a gloss meter, a digital microscope and a microscopic infrared spectrophotometer for evaluation of a seasonal impact by acidic air pollutants. The gloss losses were high on the urushi surface in autumn, when fog frequently appeared. Numerous fine spots were observed in 0.2–0.3 mm in diameter on the surfaces of the plates exposed at Chongqing, China, Taejon, Korea and Nara, Japan, where dense fog occurred. The spots were dark and opaque at Chongqing, where heavy air pollution was observed. A dark and opaque core was observed in each semitransparent spot at Taejon and Nara, while no spots were observed at Kyoto and Ishikawa, where fog often appeared but air pollution was at a low level. Carbonyl group, identified by microscopic infrared spectrometry, was found in the spots on the urushi surfaces. The carbonyl group may be formed by oxidation of a side-chain in urushiol (a major component of urushi sap, alkyl phenol). Urushi lacquer may be damaged by high concentration of sulfate anion, included in acid fog.     

Numerical Simulation of the Springtime Trans-Boundary Air Pollution in East Asia

Water, Air, &; Soil Pollution - During the spring, the high concentrations of ozone (O3) and aerosols are frequently observed aloft in Japan. Such episodes supposedly are caused by the...     

Step-By-Step Approach to Establish Acid Deposition Monitoring Network in East Asia (EANET): Thailand's Experiences

Recognizing the adverse effects of acid deposition and its transboundary nature, efforts have been made for the past six years by countries in the East Asian region to establish acid deposition monitoring network in the region by taking a step-by-step approach towards the formal establishment. The First Intergovernmental Meeting held in March 1998 agreed as the first step to implement preparatory-phase activities for two years with the aim to officially establish the EANET in the year 2000. With the successful implementation of the preparatory-phase activities, the Second Intergovernmental Meeting held in October 2000 subsequently agreed to start the activities of the EANET on a regular basis from January 2001. Thailand developed and carried out the national monitoring plan for the preparatory-phase activities through the cooperation of various agencies. Four monitoring sites were included in the preparatory-phase activities of the EANET. Monitoring capacity in Thailand has been gradually built during the preparatory-phase and Thailand is now ready to start monitoring activities of the EANET on a regular basis. Efforts should be continued to study the complex nature of acid deposition phenomena, to quantify the adverse environmental impacts of acid deposition, and to eventually reduce emissions of acid precursors. Strong supports from international and regional organizations are essential for effective implementation of the EANET activities and to address acid deposition problem in the East Asian region.     

Quality Control and Its Constraints during the Preparatory-Phase Activities of the Acid Deposition Monitoring Network in East Asia (EANET)

Participating countries of the Acid Deposition Monitoring Network in East Asia (EANET) launched the preparatory-phase activities from April 1998. For the recognition and improvement of the analytical precision and accuracy, the Interim Network Center (INC) carried out the inter-laboratory comparison on the analysis of artificial rainwater samples and soil samples. Relevant laboratories submitted their analytical data to the INC for the evaluation. Submitted data were summarized and evaluated in terms of precision and accuracy, and were compared with the Data Quality Objectives (DQOs) of EANET. These inter-laboratory comparisons made clear the present conditions of laboratories as well as the major constraints that should be solved in the future.     

The Politics of Regional Cooperation on Acid Rain Control in East Asia

Several multilateral initiatives on acid rain control were advocated in the 1990s, and extended through multiple channels in East Asia. There is, however, little coordination between those initiatives. The geopolitical make-up of the region has also hampered further progress in regional cooperation on the issue. In this paper we first examine the major features and weaknesses of existing regional environmental cooperative schemes. Second, we review collective initiatives on the acid rain issue, and examine how further progress has been hindered by the inherent inadequacies of the schemes. Finally, we consider whether and how regional cooperation on the acid rain issue may be promoted, and try to draw some implications from the European experience that might help enhance regional cooperation.     

Model Intercomparison Study of Long Range Transport and Sulfur Deposition in East Asia (MICS-ASIA)

To help improve the use of models in science & policy analysis in Asia it is necessary to have a better understanding of model performance and uncertainties. Towards this goal an intercomparison exercise has been initiated as a collaborative study of scientists interested in long-range transport in East Asia. An overview of this study is presented in this paper. The study consists of a set of prescribed test calculations with carefully controlled experiments. Models used the same domain, emission inventory, model parameters, meteorological conditions, etc. Two periods (January and May 1993) were selected to reflect long-range transport conditions under two distinct seasons. During these periods measurements of sulfur concentrations and deposition were made throughout the study region using identical sampling and analysis protocols. The intercomparison activity consists of four tasks (Blind Test, Fixed Parameter Test, Source Receptor test, and Tuning Test). All participants were asked to do Task A, and as many of the other tasks as possible. To date seven different models have participated in this study. Results and key findings are presented.     

Atmospheric Deposition of Nitrogen and Sulfur in the Yellow Sea Region: Significance of Long-Range Transport in East Asia

The amounts of nitrogen and sulfur deposited in the region of the Yellow Sea in both dry and wet forms were estimated focusing on the period between 1999 and 2000. Dry deposition fluxes were obtained using concentrations from ground stations on both Korean and Chinese sides and from shipboard and aircraft measurements. Wet deposition fluxes were determined at ground stations on the Korean side. The dry deposition flux over the Yellow Sea was much greater than those for other world oceans. As a whole, the amounts of wet depositions of nitrogen and sulfur were 1.9 and 1.5 times larger than the amounts of respective dry depositions. Substantial influence from China caused by high emissions in East China and westerly wind was possibly suggested. However, the influence from nitrogen emission in Korea was also confirmed.     

Evalution of Acid Deposition in Korea

This study was carried out to evaluate acid depositions and to understand their effect. Wet precipitation has been collected at twenty-four sites in Korea for one year of 1999. The ion concentrations such as H⁺, Na⁺, K⁺, Mg²⁺, NH₄ ⁺, Ca²⁺, Cl^?, NO₃ ^? and SO₄ ^2? were chemically analyzed and determined. Precipitation had wide range of pH(3.5～8.5), and volume-weighted average was 5.2. The contribution amounts of Cl^?, SO₄ ^2? and NO₃ ^? in anion were shown to be 54%, 32%, and 14%, respectively and those of Na⁺ and NH₄ ⁺ in cation were 32% and 25%. The ratios of Cl^? and Mg²⁺ to Na⁺ in precipitation were similar to those of seawater, which imply that great amount of Cl^? and Mg²⁺ in precipitation could be originated from seawater. The concentration of H⁺ is little related with SO₄ ^2?, NO₃ ^? and Cl^? ions, whereas nss^?SO₄ ^2? and NO₃ ^? are highly correlated with NH₄ ⁺, which could suggest that great amount of SO₄ ^2? and NO₃ ^? exist in the form of ammonium associated salt. The annual wet deposition amounts (g m^?2year^?1) of SO₄ ^2?, NO₃ ^?, Cl^?, H⁺, NH₄ ⁺, Na⁺, K⁺, Ca²⁺ and Mg²⁺ were estimated as 0.88～4.89, 0.49～4.37, 0.30～9.80, 0.001～0.031, 0.06～2.15, 0.27～4.27, 0.10～3.81, 0.23～1.59 and 0.03～0.63.     

The Importance of Calcium Deposition in Assessing Impacts of Acid Deposition in China

The extensive use of coal as an energy carrier in China has led to high deposition of sulfur in a large part of the country. In the southern part of China large areas receive acid deposition, while in the northern part of the country the acidity of the emissions is neutralized by alkaline dust from the desert areas. In this paper we demonstrate the importance of knowing the sources and deposition patterns of base cations when assessing the effects of changes in sulfur emissions. Regional-scale data of both sulfur and calcium deposition from modeling and monitoring are combined in order to demonstrate how the acidity of deposition in China has changed historically and may change in the future. The importance of base cation deposition is also demonstrated using the dynamic acidification model MAGIC with input data from an intensive monitoring site outside Guiyang. It is not known what fraction of the deposited base cations is of natural origin and anthropogenic origin, respectively. The relative source strength varies greatly between regions. Future effects of emission changes are highly dependent on the relative reduction in sulfur and base cation emissions.     

Transport of Atmospheric Pollutants from East Asia

Air-borne measurements of air pollutants transported from northeast Asia to Japan and the Pacific Ocean were carried out three times from 1996 to 1999 over the seas between Japan and Asian Continent. Those campaigns were named PEACAMPOT II under auspices of the IGAC/APARE program. A transport pattern of a highly polluted air mass from central China was found. Such air mass was driven by the quick movement of low pressure traveling from Taiwan area to the northeast of Japan. This finding supported well the results of modeling studies for long-range transport of atmospheric pollutants from East Asia.     

NMVOCs and CO Emission Inventory in East Asia

For analyzing acidification in East Asia, long range transportation models has been developed, which require emissions inventories of the precursors. SO₂ and NOx emissions inventories were reported previously; here emissions of NMVOCs (Non methane volatile organic compounds) and CO in East Asia; China, Republic Korea, Japan and Taiwan area, are estimated. For the years 1994–95, the total emissions of NMVOC and CO in East Asia are estimated at 17.7 and 94.1Tg/y respectively. Small coal boiler and biomass use for residences are dominant sources of NMVOCs in the area, especially in China. More than half of CO emission comes from biomass use in residences in China. Regionally at east costal area in China high density emission is seen in the 1×1 degree grid emission map.     

Regional Characteristics of Cooper 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.     

Establishing an acid deposition monitoring network in East Asia

Acid deposition is widely recognized as one of the most serious international atmospheric pollution problems. East Asian countries are currently experiencing acid deposition and have only recently begun expanding domestic research and monitoring activities. However, acid deposition is not only a domestic but also a transboundary problem. In addressing the transboundary aspect, cooperative and collaborative action will be essential. The Environment Agency of Japan is advocating the need to establish an acid deposition monitoring network in East Asia. Therefore, it is sponsoring three Expert Meetings on Acid Precipitation Monitoring Network in East Asia between 1993 and 1995. The meetings are attended by both scientific researchers and government officials from numerous East Asian countries. At the administrative and scientific discussions of the first two meetings a consensus on the desirability of establishing a monitoring network in East Asia was obtained and a preliminary technical guideline manual for monitoring acid deposition was adopted. By the end of the third meeting it is hoped that a basic consensus can be reached on a framework for an East Asian acid deposition monitoring network. It is essential to establish such a network in order to evaluate the present state of acid deposition in the region and to reach a common scientific understanding on the acid deposition problem. This is a vital step toward promoting international cooperation on the issue.     

Decrease in Acid Deposition - Recovery in Norwegian Waters

Concentrations of sulphate in precipitation in southern Norway have decreased by 50–60% from 1980–1999. This has caused a decrease in sulphate concentrations in lakes of 30–40% from 1986–1999. Nitrogen in precipitation has decreased slightly over the last 10-years. In lakewater there has also been a significant but slight decrease. Concentrations of non-marine base cations in precipitation have decreased by 40% from 1980–1999. In lakewater, non-marine base cation concentrations have been at about the same level the last 10 years. This indicates that acid deposition has decreased sufficiently such that the pool of exchangeable base cations in the soil is now being replenished. The acidification situation in lakes in Norway has thus shown a clear improvement over the last 8–10 years. pH, alkalinity and ANC (acid neutralising capacity) have all increased. Concentrations of inorganic (toxic) aluminium species have decreased. The trends in H⁺ and Alⁿ⁺ do not follow the relation expected if Alⁿ⁺ concentrations were governed solely by a single solid phase of Al(OH)₃.     

Soil Vulnerability and Sensitivity to Acid Deposition in China

Sensitivity, in this context, refers to `the degree to which a system will respond to acid deposition', while vulnerability is `the extent to which acid deposition may damage or harm system'.Thus, sensitivity stresses the risk of an increase in the rateof change of the soil chemistry (the acidification rate), and vulnerability stresses the risk of damage to an organism or system (the acidification state). With regard to acid depositioneffects, both vulnerable and sensitive ecosystems are of concern;however, they are usually not well distinguished. The identification of ecosystems vulnerable (at risk for damage) or sensitive (high degree of response) to acid deposition is very important if policy makers are to derive cost-effective pollutioncontrol strategies. In this paper, the relative vulnerability andsensitivity of soils in China are assessed on the basis of soil base saturation and cation exchange capacity. Vulnerable and sensitive soils, as well as the risks associated with acid deposition, are identified. The characteristics of these two types of soils and their responses to acid deposition are discussed. Finally, results obtained by using different approaches are compared. The results show that the most vulnerable areas are located mainly in Guangdong, Guangxi, Guizhou, and Sichuan provinces andin the southern part of Yunnan province. On the other hand, themost sensitive areas are located mainly in Zhejiang, Jiangxi, Hunan, and Fujian provinces and in the northern part of Yunnanprovince. Combining the distribution of vulnerability and sensitivity with the sulfur deposition shows that the areas around Chongqing City and central Guizhou province are at highrisk for damage by acid deposition; central Zhejiang province andthe boundary region between Hunan and Jiangxi provinces would be at high risk for a high rate of acidification if acid depositionwere to increase.     

Acid Deposition and Critical Load Map of Tokyo

Acid deposition has been monitored in the natural vegetation of the western part of Tokyo, especially in the Okutama Mountains and surrounding areas. However, it is difficult to grasp the condition of acid deposition and the possible impacts on the vegetation in the whole area. Therefore, we attempted to make gridded acidic deposition maps and critical load maps. The grid size was 30 seconds latitude and 45 seconds longitude. Monthly wet deposition in the fiscal year of 1997 was calculated by multiplying concentration of wet deposition and precipitation. Concentration of wet deposition was estimated by averaging the data monitored at the nearest three stations with the inverse of distance as the weight. Precipitation was estimated by step-wise multiple regression with geographical factors as explanatory variables. Critical loads were estimated using the steady-state mass balance model with some modifications. As result, it was found that sulfur deposition had exceeded in most of the western part of Tokyo.     

Modeling studies on sulfur deposition and transport in East Asia

A three dimensional regional Eulerian model of sulfur deposition and tranport has been developed. It includes emission, transport, diffusion, gas-phase and aqeous-phase chemical process, dry depostion, rainout and washout process. A looking up table method is provided to deal with the gas-phase chemical process including sulfur transfer. Calculated values have reasonable agreement with observations. Distribution of sulfur deposition and transport in East Asia are also analyzed in the paper. Simulation shows that sulfate (SO ₄ ^2– ) is the main substance to transport in long range transport. Some amount of sulfur emission of different countries transport across boundaries, but the main origin of sulfur deposition in each country in East Asia is from herself. Furthermore, some transport paths on different layers and outlet or inlet zones are found.     

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.     

Sulfur Deposition in Asia: Seasonal Behavior and Contributions from Various Energy Sectors

Sulfur transport and deposition in Asia, on an annual andseasonal basis, is analyzed using the ATMOS model. Calculationsare performed for two complete years (1990 and 1995). Deposition amounts in excess of 0.5 g S m^-2 yr^-1 are estimated for large regions in Asia, with values as high as 10 g S m^-2 yr^-1 in southeastern China. Annual averaged SO₂ concentrations in excess of 20 μg SO₂ m^-3 are calculated for many urban and suburban areas ofeastern China and S. Korea, with an average of 5 μg SO₂ m^-3 over most of the emitter regions. Sulfur deposition by major source categories is also studied. Southeast Asia (Indonesia, Malaysia, Philippines, Singapore)receives ～25% of its sulfur deposition from shipping activities. Sulfur deposition from bio-fuel burning is significant for most of the underdeveloped regions in Asia. Volcanoes are a major source of sulfur emissions in the PacificOcean, Papua New Guinea, Philippines and Southern Japan. Sulfur deposition is shown to vary significantly throughout the year.The monsoons are found to be the largest factor controlling sulfur transport and deposition in the Indian sub-continent andSoutheast Asia. India receives over 35% of its total depositionduring the summer months. In East Asia, sulfur deposition isestimated to be 10% higher during summer and fall than winterand spring. Model results are compared with observations from a number of monitoring networks in Asia and are found to be generally consistent with the limited observations.