Changes in Valued "Capacities" of Soils and Sediments as Indicators of Nonlinear and Time-Delayed Environmental Effects

This paper discusses the buffering, oxygen-donating, and sorption capacities of soils and sediments as an inter-connected system for regulating the retention and release of chemical pollutants. In this context, the author discusses the chemical conditions under which sediments may serve as a source or a sink for toxic materials, and conditions under which soils may retain or release them. It is demonstrated that nonlinear, time-delayed ecological transformations in soils and sediments often can be understood in terms of the interlinked system. The author discusses some possible future long-term environmental problems that might beset Europe, and some implications for a monitoring strategy for foreseeing such problems. Because the release of adsorbed toxic chemicals from heavily polluted sediments and soils can occur suddenly owing to changes in oxygen status (i.e., redox potential) or acidity, strategies for preventing the long-term release of such materials should not only consider current conditions of pH and redox potential, but also, how those conditions might change in the future

Chemical Time Bombs: Definition, Concepts, and Examples

This report discusses the question of the potential long-term impacts of the accumulation and mobilization of toxic and environmentally harmful chemicals in the environment. This paper deals with the potential problems caused by long-term accumulations of chemicals in the environment, cites examples of economic costs of such occurrences, and defines the means by which, under certain circumstances, such accumulations behave as "time bombs". The report gives examples of such behavior and discusses how chemical time bombs may be predicted

Industrial Metabolism and River Basin Studies: A New Approach for the Analysis of Chemical Pollution

The object of this report is to demonstrate the merit of studies in industrial metabolism as a new analytical tool for assessing the sources and flows of toxic chemicals. The methodology provides a framework for "cradle-to-grave" analysis that traces the movement of chemicals through the industrial economy, identifies the entry points through which they pass from the economy to the environment, and assesses their impact once they have entered the environment. The analysis is guided throughout by the simple constraint imposed by the principle of mass balance, which requires that the sum total of a chemical remains constant as it moves through a system from production to consumption to disposal, even as the partitioning of the chemical into various economic streams changes. Much of the analysis in this report is focused on the Rhine River Basin. The authors suggest that the spatial unit of large river basins may be ideal for studies in industrial metabolism. By definition, a river basin encompasses the land area that drains into the rivers or its tributaries. Thus, if one accounts for movements of materials into or out of the basin (particularly via atmospheric transport), it may be assumed that emissions generated within the basin can be lost from the basin only by river transport and discharge at its mouth. The remainder of the emissions (equal to total emissions minus the output from the basin) is deposited in and spatially bound by the basin, accumulating in chemical sinks, including agricultural soils, ground waters, sediments of lakes and tributaries, and landfills and toxic waste dumps. Mass balance analysis ensures that these sinks are accounted for and provides boundary conditions for assessing cumulative loads. Moreover, the tracing of chemical flows, both in the economy and environment occurs within the same spatial domain, and linkages between sources and their environmental effects are more easily established

Aqueous Emission Factors for the Industrial Discharges of Cadmium in the Rhine River Basin in the Period 1970-1990: An Inventory

This report contains an overview of the development of aqueous point source emission factors for cadmium in the Rhine River basin in the period 1970-1988. Based on these emission factors the aqueous emissions of cadmium for different industrial activities in the basin are calculated. For some activities defining emission factors does not make sense, since their cadmium emission is determined by e.g. ore or scrap purchase policy and not by the applied process technology. The overall cadmium emission to the Rhine and to its tributaries is compared with the point source component of in-basin cadmium monitoring data. The results show reasonable agreement. Further study is required to include hydrological characteristics in a tributary-Rhine model, in order to justify the comparison of monitoring data and emission estimates. In the table below, a summary of all the calculated point source emissions in time and per branch is given. A second table provides an overview of the development of emission factors for point source emissions in the Rhine River basin in time

Chemical Time Bombs: Linkages to Scenarios of Socioeconomic Development (CTB Basic Document 2)

The definition of a chemical time bomb (CTB), as provided in the first document of this series is "a concept that refers to a chain of events resulting in the delayed and sudden occurrence of harmful effects due to the mobilization of chemicals stored in soils and sediments in response to slow alterations of the environment." The theme of this second report was conceived at a workshop in the Netherlands in 1990. It was decided that chemical time bombs must be understood not only in terms of how they are triggered in the environment, but also in terms of the anthropogenic activities that are linked to the triggers. For example, a change in redox potential is a CTB trigger, and activities such as draining of wetlands an implementing sewage treatment have a major influence on redox potential. Thus, this report attempts to connect specific human activities to environmental disturbances that can stimulate CTNB phenomena. These connections are made for a range of activities, and matrices linking activities to effects are presented. The analysis is taken a step further by constructing scenarios, of land-use changes for example, and assessing their impacts with respect to CTBs. Thus, scenarios are used here not as a way of predicting the future, but rather for the purpose of presenting possible alternatives against which the risk of CTB events can be assessed. This publication is the second in a series of IIASA publications on Chemical Time Bombs. The first, entitled "Chemical Time Bombs: Definition, Concepts, and Examples," was published in 1991. The next publication in the series will discuss CTBs in landfills and contaminated lands

Emission Factors for Aqueous Industrial Cadmium Discharges to the Rhine Basin. A Historical Reconstruction of the Period 1970-1988

The report, by reviewing the relevant literature and synthesizing data on economic technologies, trade, and environmental monitoring, provides an analysis of the aqueous emissions of cadmium from industrial point sources in the Rhine Basin from 1970-1988. The report not only provides valuable input to our study of the Basin, but also demonstrates a methodology by which historical reconstructions of aqueous pollution can be attained and utilized in assessing long-term environmental trends. This historical Rhine Basin study provides a much needed database for further understanding of the institutional, political, and social factors that shaped the pollution landscape in previous decades and led to the remarkable cleanup that has occurred more recently. Such information is urgently needed for guiding policies, particularly in the newly industrialized regions of the world, such as southeast China, and in highly polluted river basins, such as in Eastern Europe

Land Use Change in Europe- Scenarios for a Project Area in East Germany, Poland and the Czech Republic

This study identifies plausible scenarios for land use changes for a project area located at the coexistent borders of Poland, the Czech Republic and East Germany. The time frame is 1992 to 2050 with an intermediate step in 2020. The basis for the scenarios is an analysis of the driving forces for land use change in the context of the study area. The main emphasis here is on the EU's Common Agricultural Policy and trends in agriculture and forestry in the three countries of the project area. In addition former land use change, spread of urban areas, the state of mining areas, recreation and nature conservation and policies related to land use planning are of importance and therefore analyzed for each country. The direction of land use change between 1960 and present was a decrease in agricultural land and an increase in forest and 'other' area, which mainly consists of urban area and area for infrastructure. Recent changes in the Common Agricultural Policy aim at reducing overproduction an cut spending in general. The prevailing tendency is to liberalize the agricultural sector to shift from product tied payments to direct payments to farmers for social, environmental or cultural duties. Since the political changes in 1989 the three countries of the project area have undergone significant economic and structural changes. East Germany as part of Unified Germany and part of the EU has experienced the most drastic restructuring of the agricultural sector with the main feature of major job losses and production decreases, especially in the livestock sector. Similar developments, though not as radical, can be observed in Poland and the Czech Republic. The first Scenario, "Large Scale Increase of Wooded Area", anticipates the introduction of a free market economy to the agricultural sector. No more subsidies are required for agriculture. Large areas of marginal farmland have to be taken out of production. The price of land decreases. Farmers will either afforest their farmland or sell it to non-agricultural uses like urban development, recreation or nature conservation are options for farmers. A quantification for the project area foresees by 2050 a decrease of agricultural land to half of its size in 1992, a doubling of forest and an increase of 'other' area by 80%. Scenario 2, "Alternative Agricultural Products", assumes a shift from food production to nonfood products, mainly biofuel and incentives for an extensification of agricultural production. Subsidies, that are still required for the agricultural sector, will be kept. The overall policy aims at keeping the land open, avoiding uncontrolled spreading of urban development and providing prospect for development and employment in rural areas. The main characteristic of Scenario 3, "Europe as Food Exporter", is an increase in the demand for agricultural products, which by approximately 2010 triggers a increase in the world market price for food products. Reasons for this are population and wealth increase, especially in China an south east Asia, combined with environmental constraints like water or fertile land scarcity and erosion. As a result agricultural production in Europe becomes prosperous in the frame of a free market environment. No further subsidies are required for the sector. Until 2010 the development is similar to Scenario 2. Scenario 2 and 3 show only modest changes in land use patterns, but the agricultural production structure differs. Scenario 2 focuses on a mixture of food and non-food products, while in Scenario 3 all available farmland is used for food production after 2010