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Part 2: Case-studies

6. Industrial metabolism at the national level: A case-study on chromium and lead pollution in Sweden, 1880-1980

Introduction
The use of chromium and lead in Sweden
Calculation of emissions
The development of emissions over time
The emerging immission landscape
Conclusions
References

7. Industrial metabolism at the regional level: The Rhine Basin

Introduction
Geographic features of the Rhine basin
Methodology
The example of cadmium
Conclusions
References

8. Industrial metabolism at the regional and local level: A casestudy on a Swiss region

Introduction
Methodology
Results
Conclusions
References

9. A historical reconstruction of carbon monoxide and methane emissions in the United States, 1880-1980

Introduction
Carbon monoxide (CO)
Methane (CH4)
References

10. Sulphur and nitrogen emission trends for the United States: An application of the materials flow approach

Introduction
Sulphur emissions
Nitrogen oxides emissions
Conclusion
References

11. Consumptive uses and losses of toxic heavy metals in the United States, 1880-1980

Introduction
Production-related heavy metal emissions
Emissions coefficients for production
Consumption-related heavy metal emissions
Emissions coefficient for consumption
Historical usage patterns
Conclusions
References

6. Industrial metabolism at the national level: A case-study on chromium and lead pollution in Sweden, 1880-1980

Ulrik Lohm, Stefan Anderberg, and Bo Bergbäck

Introduction

In many countries, estimations of annual emissions of chemicals from point sources are now being regularly presented for the nation as a whole. For Sweden, the figures show that the emissions have been decreasing since the mid-1970s. This is, of course, encouraging with regard to environmental protection objectives. Unfortunately, however, these figures do not present a complete picture. Nor do they provide sufficient information to evaluate human impact on the environment systematically, especially in a long-term perspective. There are two major shortcomings of the standard estimates:

1. Lack of a spatial dimension; a nationwide scale is hardly satisfactory to assess impacts (or the value) of reduced industrial emissions.
2. Lack of a temporal dimension; to evaluate present pollution loadings, knowledge about the dimension and localization of past emissions is needed.

The development of industry in Sweden has led to an increased use of chemicals and other materials. In this study we want to approach the environmental problems of tomorrow that will arise from the use of various materials, from a historical standpoint. This type of study could be used as an argument for what has recently been called the precautionary principle of environmental management (see O'Riordan, chapter 12 of this volume). The purpose is to develop methods to reconstruct the flows of materials and estimate the emissions over time. This is done through studies of the development of production, technology, trade, and the longevity of products in society. This last part in the chain will form the "consumption emissions."

The concept of industrial metabolism suggests that we should seek to estimate the total load of toxic substances in soils and sediments, i.e. to describe and assess the development of a new "immission landscape." In this chapter industrial metabolism is illustrated in terms of the total flow and accumulation of chromium (1920-1980) and lead (18801980) in Sweden (Anderberg et al., 1989, 1990; Bergbäck et al., 1989, 1992).

The method of analysis is based on a simplified flow scheme: Various substances enter the economy either through imports or domestic production. Production of goods and extraction of primary materials result in "production emissions." The main part of these emissions is found in the products themselves, and is accumulating in the "anthroposphere." Depending on the type of product, large amounts may remain for a long time. Some parts are recycled after use. However, a significant quantity is sooner or later spread to the environment through consumption emissions, dissipative losses (see Ayres, chapter 1 of this volume), consumer-related emissions, or emissions from diffuse sources.

This materials' balance approach method (inspired by Ayres and Kneese, 1969; Ayres, 1978; Ayres and Rod, 1986; Tarr and Ayres, 1990) consists, in somewhat simplified form, of the following steps:
1. Construction of flow schemes for various substances.
2. Collection of data concerning production, trade, and technology with the aim of filling the boxes in the flow schemes and creating a base for assumptions concerning emissions.
3. Estimating the emissions over time, using the net surplus and the flow scheme of the substance; emission coefficients concerning consumption are based on "life-expectancy" of the product in the technosphere.
4. Calculation of the anthropogenic amounts of stable substances in the soil and sediments per region and decade, i.e. the immission landscape.

The use of chromium and lead in Sweden

In Sweden, the use of chromium has been quite extensive owing to the historic importance of steel alloy production. As there are no chromium mines in Sweden, the import of chromium ore has long made up more than half of total Swedish ore imports. These imports have increased dramatically during this century. Imported chromium ore is mainly used for the production of ferrochrome. Since 1920, the Swedish iron and steel industry has been the major user of chromium, particularly for stainless steel. The use of chromium in the leathertanning and textile industries was once important, but with the decline of these industries and the introduction of synthetic materials for tanning and dyeing, this use has decreased rapidly. The chemical industry and anti-corrosion treatment have replaced these industries as the major users of imported chromium compounds.

Lead mining has a long history in Sweden, but it is only since the Second World War that it has really been important; Sweden has become a major lead producer and ore exporter in Europe. Still, imports of various lead products have also been quite significant, particularly between 1945 and 1980. Traditionally, pigments and metal products were the most important uses, but since 1920 the electrical industry (cables and batteries) has been the dominant user, with 7080 per cent of total consumption.

Calculation of emissions

Production emissions

Production emissions of chromium have been estimated for the ferrochrome alloy and steel industries and for leather tanneries. These activities contributed more than 90 per cent of the chromium emissions to water, and almost 100 per cent to the air in the late 1970s, according to estimates by the Swedish Environmental Protection Board.

For lead, the emissions have been calculated for metalworks, the iron and steel industry, glassworks, the rubber industry, and battery manufacturing. These branches were responsible for approximately 95 per cent of the emissions to air and water in the late 1970s.

The method for calculating time series for production emissions has been to use the best available single-year estimate of uncontrolled emissions for the various branches. We then let the emissions follow the development of production and/or use of lead/chromium backward in time. The emissions from a particular branch of industry were distributed between the individual factories according to the number of workers employed, or the production figures at different periods in time (10-year periods, except for the first and last periods, where five years were used). Finally, the total emissions per time period and region were summed up.

Consumption emissions

For consumption emissions, specific factors for various products have been used (see below). Here, the emissions were distributed between regions according to the distribution of population, except in the case of gasoline, where sales statistics were used.

The diffusion of lead or chromium from a certain use was calculated as follows

A x E x T

where A is the share of total lead/chromium consumption for the particular use, E is the assumed emission factor, and T is net consumption, from which the consumption of lead in gasoline and ammunition has been subtracted. The emission factor (see table 1) is defined as the part of the product that is mobilized in the environment within a decade. (Here we have used the factors given by Tarr and Ayres, 1990.) The emissions from gasoline and ammunition have been calculated separately, assuming that 80 per cent and 100 per cent of the lead content, respectively, will reach the environment.

Table 1 Emission factors for calculation of consumption emissions

Source: Tarr and Ayres, 1990; Ayres and Ayres, in this volume.

The development of emissions over time

In Sweden, the production emissions of chromium increased drastically in the period 1910-1970. Until the 1950s, tanning (see table 2) was the main source of chromium pollution, while steel and ferrochrome plants (see table 3) dominated the emissions after 1960. Despite a continued increase in chrome alloy steel production, the emissions drastically decreased in the 1970s, owing to an increasingly effective control programme.

The use of chromium in Sweden has increased constantly since the beginning of the century. Between 1950 and 1980, imports increased more than sixfold (see table 4). Most of the chromium will end up in the technosphere in numerous products. Even if only very small quantities are assumed to reach the environment, in the long run these emissions will be most significant. As consumption emissions are still increasing, leaching from chromium products appears to be a major future source of pollution.

Table 2 Calculated chromium emissions from tanneries in Sweden, 1910-1980

Source: Swedish Industrial Statistics, various years.

Table 3 Calculated chromium emissions from ferrochrome alloy and steel plants in Sweden, 1920-1980

Source: Swedish Industrial Statistics, various years.

Table 4 Total consumption emissions in Sweden, 1920-1980 (calculated from import surplus)

Source: Swedish Trade Statistics, various years.

For lead, production emissions culminated in the 1970s, but owing to improved production control are now relatively limited. The total production emissions to air in the period 1880-1980 (see table 5) have been dominated by one particular metalworks (Rönnskär), with a percentage of up to 57 per cent. Other contributors have been iron and steel production (16 per cent), rubber (12 per cent), glass (11 per cent), and battery manufacture (2 per cent). The major sources of total emissions to water (see table 6) have been metalworks (47 per cent), iron and steel (39 per cent), mining (9 per cent), and crystal glass production (5 per cent).

The consumption of lead in Sweden increased drastically in conjunction with rapid industrialization, by more than 40 times between 1880 and 1960. But since then it has decreased because of the stagnation in some of its major areas of use, and also because of increased recycling. The shares of the various uses have changed significantly over the hundred years. By the end of the last century, metal products and chemicals, mostly white and red lead used in paint, were dominant. Since around 1920, most of the lead has been used for cables and batteries, while metal products and chemicals have kept stable shares of 10-15 per cent each (see table 7).

Table 5 Calculated lead emissions to air in Sweden, 1880-1980 (based on production figures), in tonnes per year

Source: For production figures: Swedish Industrial Statistics. various years.

a. Estimated by the Swedish Environmental Protection Board.

Table 6 Calculated lead emissions to water in Sweden, 1880-1980 (based on production figures), in tonnes per year

Source: Swedish Trade Statistics, various years. a. Estimated by the Swedish Environmental Protection Board.

After the Second World War tetraethyl lead was introduced as an additive to gasoline. Around 1970 this use reached over 2,000 tonnes, or 3.5 per cent of total consumption. Even though this share is rather small, it has by far been the most important emission source during the latter half of the century. The production and import of lead shot and cartridges have fluctuated considerably throughout the century, but ammunition has always been a significant source of lead emissions. The total amount of lead emissions calculated from both production and consumption was approximately 190,000 tonnes between 1880 and 1980. The share of consumption emissions was 85 per cent, with about one-fourth each from both ammunition and gasoline, and one-third from other consumer uses (e.g. lead pigments, cables, and batteries). The emissions from consumption have dominated for the whole period studied (see figure 1).

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