Spatial variability in emissions reduction strategies for sulphur and nitrogen in the UK

The roles of sulphur (S) and nitrogen (N) in causing critical loads exceedance across the UK show considerable spatial variability at the present time. Over much of lowland Britain it appears that the environment can only be protected by reducing N deposition, whilst in upland areas (e.g. most of Scotland and Wales) reductions in S deposition are the primary requirement. Using the Hull Acid Rain Model (HARM) the effects of current and possible future emissions control legislation on critical loads exceedance can be explored. Based on HARM output, the implementation of the UNECE Sulphur Protocol (1994) will bring about a substantial reduction in the amount of S being deposited in the UK, especially in central and southern parts of the country. Some areas will remain where additional reductions in S are required. Over most of the country, however, the need to reduce N deposition will become paramount. The changing contributions and significance of non-UK sources can be estimated.     

Interdependence of air,water, and soil pollution control strategies in a power plant and a kraft mill

An analysis of cross-media (air, water, and soil) emissions resulting from various control strategies is necessary in the evaluations of emission standards as well as control strategies. This paper presents such analysis on seven control strategies for a coal-fired power plant and ten control strategies for a kraft pulp and paper mill. The data illustrated include uncontrolled and controlled emissions to all three environmental media as well as power requirement, and capital and operating costs.     

Control techniques and strategies for regional air pollution control from energy and industrial sectors

The technological options currently available to reduce SO₂ and NO_x emissions including abatement technologies and high efficient energy conversion technologies are reviewed. The energy emission model EFOMENV (Energy Flow Optimization Model-Environment) which takes into account all relevant emission reduction measures is used to determine the cost optimized energy pathway, the ranking of reduction measures and the corresponding costs as a function of given reduction levels of SO₂ and/or NO_x emissions for different scenarios in selected Central and Eastern European countries. It is shown that restructuring of the energy system is a major emission reduction option in all countries but with a potential varying greatly from country to country depending mainly on the existing structure and the age of the plants and on the development of the energy demand. The emission reduction costs for SO₂ in Central and Eastern European countries are 50% to 70% lower than in Western countries due to high potential of fuel/technology switching and energy saving measures. Cost efficient measures to reduce CO₂ emissions also lead to a significant decrease of SO₂ and NO_x emissions.     

Analytical air pollution advection and diffusion models

A review of non-Gaussian analytical solutions of the advection diffusion equation is presented. Their utilization to mathematical models of air pollution diffusion is discussed and the application of a particular solution is suggested. The suggested KAPPAG model uses the Demuth's (1978) solution and can incorporate smoothed observed vertical wind and diffusion coefficient profiles. It is shown that Demuth's solution can represent the realistic situations of the diminishing vertical exchange coefficient at the top of boundary layer.     

Tree bark as a bioindicator of air pollution in Navarra,Spain

During a two year research period from 1992 to 1993, samples of different species of trees were taken in 17 forest stands located in Navarra, Spain. From these samples, bark extracts were prepared in which the pH and the conductivity were measured. The health of the sampling trees was also evaluated by determining the degree of defoliation and decoloration of the canopies. The bark tissue analysis revealed the presence of an environmental acidity gradient that decreased from NW to SE. This coincides with the location of important sources of pollution and their course of transport and dispersion. On the other hand, in the samples ofQuercus ilex a significant correlation between the pH and the defoliation levels (P≤0.01, r=0.62) was found. This fact reveals the potential usefulness of tree bark as a health bioindicator of trees.     

Harmonization of air pollution control in the European community

In the first Action Programme of the Environment approved by the Council of Ministers on 22 November, 1973, the Commission of the European Communities was requested to determine criteria, to propose quality objectives and standards, to develop exchanges between Member States of measurement data from pollution control networks, to harmonize produce specification and actions with the industrial sector. A critical review is given in this presentation of the progress made in this respect at Community level and of the difficulties met. It can be stated that important progress has been made to harmonize national policies and to elaborate a Community policy in this field, notwithstanding the difficulties of smoothing away differences in existing and established national policies and situations.     

Direct and indirect air pollution effects on materials including cultural monuments

Damage caused to materials exposed in the atmosphere constitutes one of the most important direct effects of acidifying air pollutants. Systematic field and laboratory investigations performed in the recent decade in many countries have contributed to a considerable increase in the knowledge on the mechanisms of the effects of pollutants, on the quantification of damage and on the assessment of the cost of damage. Beside the very important role of SO₂ for several materials also studies of the direct or synergistic effect of NO_x and O₃ have contributed to the understanding of the complex pollution effects. Even if there are still considerable gaps of knowledge it seems that NO_x and O₃ may contribute in an important way to the deterioration of several materials also in indoor environments which are important for i.a. electronic equipment, storage conditions and museums. Important knowledge has been gained from the International Cooperation Project within UK ECE which is an extensive field exposure on 39 test sites. Dose-response relations have been obtained after 4-year exposure showing the effect of dry and wet deposition on corrosion of several material groups. Also the effect of micro- and mesoclimate on corrosion of building materials like plaster and bricks in different positions on buildings and locations within an urban area has been subject to systematic studies. Results from the studies are used i.a. for assessment of so called acceptable corrosion levels and for mapping areas where the levels are exceeded at different pollution scenarios, as well as for calculation of economic damage. Based on model studies for some city areas tentative calculations of damage cost have been performed for the European region. The indirect effects consist of increased corrosion due to water and soil acidification which are of importance in geologically sensitive areas. Structures which are in contact with soil and water represent a very great capital investment and are of vital importance to the community.     

Tropical land use change and soil emissions of nitrogen oxides

Abstract. Increases in the emissions of globally important nitrogen (N) oxide gases have coincided with significant changes in land use in the tropics. Clearing of tropical forests and savannas for agriculture currently represents the most extensive alteration of land cover on the planet. Over the last several decades, N fertilizer use has increased globally, and in China and the developing world, use has recently surpassed that in the developed world. The potential contribution of land-use change in the tropics to the increase in N oxides is great, yet only a few studies have measured N oxide emissions after tropical land conversion. Our summary of available research shows some conversions to pastures and a few management practices, especially those using N fertilizers, increase emissions beyond those found in undisturbed ecosystems. However, not all studies show unequivocal increases in emissions. Accordingly, we call for a mechanistic understanding of the processes controlling trace gas fluxes to adequately predict under what conditions increased emissions may occur. More measurements are needed to build and test models that may improve management of N fertilizer use in tropical agricultural systems. Given the expected expansion of agriculture and increased use of N fertilizers in the tropics, increased emissions of N oxides from the tropics are likely.     

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.     

Overview of historical and paleoecological studies of acidic air pollution and its effects

Historical evidence of acid deposition and its effects which was presented at Muskoka, Ontario in September, 1985 is summarized. This evidence consists of written records of the past chemistry and biology of atmospheric, terrestrial, and aquatic systems; it also includes evidence from archived collections which were “revisited”, from tree rings, and from the chemical and biological “records” in lake sediment and peat from which histories of airborne contaminants and ecosystem responses to these contaminants were inferred.     

Techniques and strategies for the reduction of ammonia emission from agriculture

Agricultural production systems are recognised as a major source of atmospheric ammonia (NH₃). When deposited, the NH₃ may contribute to eutrophication of oligotrophic ecosystems and to acidification. Techniques for the reduction of ammonia emission are mainly focused on reducing the NH₃ emitting area exposed to the air, reducing the NH₃ or ammonium (NH ₄ ⁺ ) concentration in solution or reducing the exchange of air above the emitting surface. In this paper we present the techniques and changes in farming practice which may reduce NH₃ emission. Due to interactions between different sources on a farm, reduction in NH₃ emission from individual parts of the livestock production system cannot simply be added to give the net reduction in emission from the total system. Thus a whole farm system approach is needed for devising control strategies for reducing NH₃ emission.     

Heavy metal levels in earthworms of a forest ecosystem influenced by traffic and air pollution

Soils of a forest ecosystem in Berlin (West) are highly polluted by Pb and less polluted by Cd and Cu. Pb levels in earthworm species depend primarily on soil type and only secondarily on the distance from a highway crossing the forest. The dominating species Lumbricus rubellus and Dendrobaena octaedra show different body burdens especially of Cd. Liming the forest soils decreases the Pb concentrations significantly. Only in D. octaedra has body weight been found to be related to Pb; Pb has been increased from 50 mg kg^–1 in small to 250 mg kg^–1 in large specimens; Cu has been regulated at a more or less constant absolute level (about 0.4 pg per specimen). This species obviously regulates or accumulates the three metals in different ways. Centipedes as predators of earthworms in the sites show markedly less pollution of Pb and Cd (about 2.5 and 0.6 mg kg^–1) than the worms, but higher concentrations of the essential Cu (about 40 mg kg^–1). The use of earthworms as indicators of heavy metal pollution should take into account the biology of the various species, the soil type, the type and amount of organic matter as well as chemical parameters such as pH value or basic anions.     

Background pollution in the Arctic air mass and its relevance to North American acid rain studies

The Arctic air mass is a unique meteorological feature of the northern hemispheric atmosphere. Possessing well-defined meteorological characteristics, it occupies not only the polar region but also a large fraction of the Canadian and Eurasian land masses during the period November to April. Poor pollutant removal by precipitation and dry deposition within the air mass and a strong transport pathway between Eurasian mid-latitudinal sources and the north, result in elevated levels of acidic anthropogenic aerosols and gases in the air mass during winter. In summer, weak north/south transport and strong pollutant removal between the Arctic and mid-latitudes and within the Arctic, results in lower airborne concentrations of acidic pollutants. Due to the presence of the relatively polluted Arctic air mass, ‘background’ air concentrations of SO₄ ⁼, SO₂ and total NO₃ ^? are elevated in western Canada during winter. Typical mean monthly concentrations from December to March are 0.8 to 2.1, 1.0 to 2.4 and 0.1 ? 0.6 μg m^?3, respectively. In the absence of the neutralizing influence of alkaline soil dust, the acidity of snow forming in western Canada during winter is expected to range from 5 to 20 μeq l ^?1.     

The use of clams as bioindicator of fecal pollution in seawater

The coastal waters of Kuwait are widely used for bathing during the long summer season. In order to assess the water quality along the beaches, a new approach was developed. It involves the use of clam, Circenita callipyga, as a bioindicator for seawater pollution by fecal coliform bacteria (FC), antibotic resistant fecal coliform (ABR-FC) and Salmonella spp. These organisms were detected in clam and water samples and the efficiency of clam in concentrating Salmonella was confirmed. The number of FC and ABR-FC in clam and water samples were compared and a higher number was detected in clams than in water. Five isolates of Salmonella from clams were also multidrug resistant. The data suggests that clam can be used as a bioindicator of seawater pollution and is preferable to direct testing of water. The resistance to antibiotics in E. coli isolated from water and clams collected at the same time and site was of similar pattern and was determined by R-plasmid.