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Update on Impact Categories, Normalisation and Weighting in LCA

10 Ecotoxicity

• 10.1 Summary
• 10.2 Description of the impact category
• 10.3 Methodology
• 10.4 Normalisation reference - Aquatic environment
• 10.5 Normalisation reference - Terrestrial environment
• 10.6 Normalisation references
• 10.7 Comparison with the previously used normalisation reference
• 10.8 Evaluation of uncertainties
• 10.9 Recommendations
• 10.10 References
• Appendix A: Emissions to the aquatic enironment, metals
• Appendix B.1 Emissions to the aquatic environment, organic substances - Denmark
• Appendix B.2: Emissions to the aquatic environment, organic substances - EU-15
• Appendix C: Emissions to the aquatic environment, atmospheric deposition
• Appendix D: Emissions to the terrestrial environment, pesticides
• Appendix E.1: Emissions to the terrestrial environment, sewage sludge applied in agriculture - Denmark
• Appendix E.2: Emissions to the terrestrial environment, sewage sludge applied in agriculture - EU-15

Jens Tørsløv, DHI - Water & Environment

10.1 Summary

This chapter summarises the presently available data on environmental releases of toxic organic and inorganic substances to the Danish and European environment. The estimated releases include:

Aquatic environment:

• Releases of organic pollutants with wastewater
• Releases of metals
• Emissions of oil from oil extraction and refineries
• Release of organotin compounds from antifouling paints
• Atmospheric deposition

Terrestrial environment:

• Pesticide use
• Agricultural use of sewage sludge
• Atmospheric deposition of metals and dioxins

The ecotoxicological impact is estimated from the released amounts of the individual chemicals and expressed as the volume of water and soil in 1994 (reference year) that was theoretically polluted to a level which corresponds to the no-effect concentration of the substances, assuming an even distribution of the pollution.

The main results are presented in Table 10-1.

Table 10-1
Summary of normalisation references for ecotoxicity for Denmark, EU-15 and Worldwide in 1994.

ETWC: Ecotoxicity Potential for chronic effects on aquatic organisms.

ETWA: Ecotoxicity Potential for acute effects on aquatic organisms.

ETSC: Ecotoxicity Potential for chronic effects on soil organisms.

The dominating release of toxicants originates from the use of pesticides in agriculture and the use of antifouling paints, containing tributyltin compounds, on ships. The uncertainties of these releases are high and probably over one order of magnitude. Consequently, the results presented above should be regarded as rough estimates with a high degree of uncertainty. In order to obtain more precise results it is recommended to improve the estimates of the emission from these sources.

10.2 Description of the impact category

The purpose has been to prepare a normalisation reference for ecotoxicological impacts based on data collected from European national environmental agencies as well as international data centres. The work is based on 1994 data and covers Denmark and the European Union. In addition a rough estimate of the ecotoxicity potential on a worldwide basis is presented.

The impact category ecotoxicity covers the possible effects of toxic substances released during the life cycle of a product to the environment. The sources of toxicants are quite different depending on the type of environment as well as the methods used in the assessment of the impact. Consequently, the impact on aquatic and terrestrial systems are usually considered separately.

In principle, the normalisation reference for ecotoxicology includes all toxic substances emitted to the environment due to human activities, and it requires extensive data on all types of emissions. In general, however, only few data on environmental releases of toxic substances are available, and the normalisation therefore relies on extrapolations from a relatively limited set of data.

The normalisation reference includes the following emission types:

Aquatic environment:

• Releases of organic pollutants with wastewater
• Releases of metals
• Emissions of oil from oil extraction and refineries
• Release of organotin compounds from antifouling paints
• Atmospheric deposition

Terrestrial environment:

• Pesticide use
• Agricultural use of sewage sludge
• Atmospheric deposition of metals and dioxins

10.3 Methodology

The presented estimates of the ecotoxicological impacts are based on estimated releases of toxicants to the aquatic and terrestrial environments on the basis of statistics on emitted volumes of wastewater, sludges, pesticides, etc. as well as concentrations measured in different environmental media. The data sources and the methods used for estimation of the releases from different types of sources are discussed together with an evaluation of the uncertainties involved in the sections below.

In order to obtain a quantitative and comparable value for the ecotoxicity potential (EP), the released amounts of individual substances are multiplied by a substance-specific factor, the equivalency factor (EQF), which corresponds to the potential environmental impact of the substance according to the principles described in Hauschild et al. (1998). The EQF for the single substances are derived from the predicted no-effect concentration (PNEC) based on the toxicity to aquatic or soil organisms, the biodegradability, the bioaccumulation potential, and the calculated environmental distribution. The EP is calculated for the individual emission types evaluated and for the following effect types:

• Acute aquatic toxicity
• Chronic aquatic toxicity
• Chronic terrestrial toxicity

In a few cases it was necessary to calculate new EQF values as not earlier included substances were found in emission surveys, i.e. if no EQF was available or if a revision of the existing EQF was required. In general, however, it was not possible, within the frame of the project, to revise or generate equivalency factors.

The toxicity to the microflora in wastewater treatment plants (WWTP) was included in the former Danish normalisation reference but it is excluded here for the following reasons:

1. It is not possible to estimate the potential impact on WWTP because of the lack of reliable data. Estimations of the effects on wastewater treatment plants require data for toxicity to microbiological treatment processes such as nitrification, respiration or similar relevant parameters. Such data are available only for a few organic and inorganic substances.
2. Effects on wastewater treatment plants have an environmental relevance but are an indirect measure for the environmental impact from treatment plants. There is no simple relationship between an impaired wastewater treatment and the environmental impact of the emitted wastewater.
3. The impact on a wastewater treatment facility depends on the toxicity of the emitted wastewater as well as the sensitivity of the facility. A modern treatment plant with N and P removal is normally regarded as more sensitive to toxic substances than more traditional treatment techniques. Consequently, the impact strongly depends on the wastewater technology used in different countries.

The results presented here are based on a high number of calculations and assumptions. Background data for the individual emission types and data for the different geographical regions are presented in Appendices A-E.

10.4 Normalisation reference – Aquatic environment

The normalisation reference for the aquatic environment includes those contained in the previous normalisation reference (Hauschild et al. 1998), i.e. wastewater, emissions from oil extraction activities, and atmospheric depositions. In addition the release of toxicants from the use of tributyltin-based antifouling paints is included. The primary data references are shown in Table 10-2.

Table 10-2
Emission types and selected references used for the estimation of emissions to the aquatic environment.

Because of the methodological differences and differences in the used data sources, heavy metals, organic substances, oil emissions, antifouling, and air deposition are separately discussed in the following sections.

10.4.1 Emission of heavy metals

10.4.1.1 Data sources

For 10 European countries the emission of heavy metals to the aquatic environment has been estimated in a recent report from the EUROSTAT (EUROSTAT, 1998). These estimates are based on data from the European Topic Centre on Marine Environment (ENEA), the Helsinki Commission (HELCOM), the Oslo and Paris Commission (OSPAR), the Barcelona Commission, and the Danube Commission. The emissions are based on data on riverine and direct input of heavy metals to the marine environment and include the marine and coastal areas from Gibraltar to the Gulf of Bothnia.

The OSPAR data used by EUROSTAT (1998) include high as well as low estimates of the emitted amounts of toxic heavy metals. The high estimates were based on measured concentrations, and in cases where the substances were not detectable the detection limits were used. The low estimates were based on zero values if the substances were not detected. At emissions less than 1 tonne/year, a value of zero is used in the present report. The data from OSPAR cover the period of 1990 – 1995, and the data from HELCOM refer to 1995.

As to the countries not included in EUROSTAT (1998), the emissions were estimated by linear extrapolation from emission data from the Netherlands (NL), reported by van der Auweraert et al. (1996) by use of the Gross Domestic Product (GDP).

The Danish emissions of metals were estimated from measured concentrations in discharged wastewater from municipal treatment plants and estimated releases from other sources based on mass balance studies of the individual metals (Grüttner & Neergaard Jakobsen 1994; Grüttner et al. 1996; DEPA 1995; Lassen et al. 1996a; DEPA 1996; Lassen & Hansen 1996; Lassen et al. 1996b; Jensen & Markussen 1993).

Lead from loss of fishing equipment and cable sheets is a significant source (Danish release: 150-575 tonnes/yr., Lassen and Hansen (1996)) but is not included in the present report because metallic lead is available to the biota only to a very limited extent.

Only emissions of mercury (Hg), cadmium (Cd), copper (Cu), zinc (Zn), and lead (Pb) are included in this report.

10.4.1.2 Results

The ecotoxicity potential (expressed as m³/yr.) for the metals are calculated according to Hauschild et al. (1998) by multiplying the total emission of the individual metals with an equivalency factor (EF) (Table 10-3).

Table 10-3
Estimates of the ecotoxicity potential for metals emitted to the aquatic environment. The estimates are based on the emission reported by EUROSTAT (1998).

etwc: ecotoxicity potential for chronic toxicity to aquatic biota

etwa: ecotoxicity potential for acute toxicity to aquatic biota

The background data for these estimates, including emission data for the individual European countries, are included in Appendix A.

10.4.1.3 Discussion

The precision of the EUROSTAT data is validated by comparing with the Danish and NL releases of heavy metals. This is done by comparing the Danish releases of metals presented above with estimated Danish releases based on an extrapolation by use of EUROSTAT data. The extrapolation is based on linear extrapolation by use of the Gross Domestic Product (GDP). Similarly metal releases for the Netherlands, reported by van der Auweraert et al. (1996), are compared with an estimate based on EUROSTAT-data. The data are compared in Table 10-4.

Table 10-4
Estimated emissions of selected metals to the aquatic environment.

Extrapolation based on the Gross Domestic Product (GDP). NL data by van der Auweraert et al. (1996)

The figure does not include loss of commercial fishing equipment, which is estimated to be approx. 100-275 tonnes/yr. (Lassen & Hansen 1996).

Estimates based on measured wastewater concentrations and releases from other sources.

Data by van der Auweraert et al. (1996).

The data for the EU-15, which are based on extrapolation from EUROSTAT data, correspond well with the results obtained by extrapolation from the Netherlands by use of the Gross Domestic Products (GDP). This apparent compliance covers, however, some methodological differences and uncertainties.

The data on releases of cadmium, copper, and zinc to the Danish aquatic environment correspond within a factor of 2 with the extrapolated EUROSTAT-data. However, the figures for emission of mercury and lead show more significant differences.

The EUROSTAT data for the NL are a factor 5 - 10 higher than the data reported by van der Auweraert et al. (1996). These data are based on measured concentrations in municipal and industrial discharges and can be regarded as highly reliable. The differences can be explained by the fact that the EUROSTAT data are based on riverine inputs to the North Sea, i.e. measurements of river water, including emissions from Germany and other countries upstream as well as diffuse and natural sources.

The composition of the wastewater and thus the emissions of organic micropollutants and heavy metals depend on the treatment processes applied. The well-developed treatment technologies used in some European countries reduce the pollutants in the wastewater more efficiently than less sophisticated techniques. This will, together with differences in the composition of the industrial sectors between countries, introduce an error when the Gross Domestic Product is used as a basis for extrapolation.

The most important uncertainties are:

• The estimates from EUROSTAT are based on riverine and direct inputs to the marine environment and thus include natural sources. The figures do not include emissions of metals, which are bound to sediments upstream in the river basins. Furthermore, the used figures represent minimum estimates because zero values are used in case the concentrations are below the detection limits. Comparison with Danish estimates based on measured concentrations in wastewater and estimated releases corresponds, however, well with the EUROSTAT data.
• For some countries the releases of metals are based on extrapolation from NL data. It should be stressed that differences in the industrial sources and the wastewater treatment methods applied in European countries are an important source to uncertainty of the estimated releases.
• Only some metals are included in the estimates. By focusing on the dominating toxicants this error is, however, minimised, but the results should be regarded as a minimum estimate of the ecotoxicity potential.

10.4.2 Emission of organic substances

10.4.2.1 Data sources

The emission of toxicants from industrial sources is difficult to estimate because of the differences in the composition of the wastewaters and the limited amount of data. The normalisation reference used by Hauschild et al. (1998) was based on directly measured toxicities of Danish industrial wastewater emissions. These data are, however, not updated and probably not available from other countries.

In general, there are only few data on emissions of organic micropollutants to the aquatic environment in Europe. The most comprehensive data compilation is made by van der Auweraert et al. (1996), which covers emissions from over 700 industrial sources and municipal treatment facilities in NL and includes approximately 100 individual parameters. Furthermore, a few organic micropollutants are reported by DETR (1999). In Germany the industrial emissions are estimated for selected industrial sectors only, but no national emission reference has been found (UBA 1999).

In Denmark a few selected organic substances have been monitored in wastewater from municipal treatment plants, but information on the emission of individual organic substances from industrial sources does not exist. Some of the most reliable Danish data are estimates of the emissions of selected substances based on mass balances on national levels and statistical reports published by the Danish EPA on an annual basis (DEPA 1995). Moreover, the Danish EPA has published a collection of data on emission of 38 single substances including organic solvents and heavy metals (Holmegaard Hansen, 1995). None of these data sources provides a base of data as extensive as the NL data.

Consequently, the emissions of organic substances via Danish and European wastewater sources are, in the present report, based on NL data extrapolated by use of GDP. To some extent these estimates can be validated by comparison with available national data (see discussion).

10.4.2.2 Results

Data for the environmental release of organic pollutants in NL are presented in Table 10-5. Industrial direct outlets as well as municipal wastewater emissions are included in the figures.

Table 10-5
Emission of organic substances to the aquatic environment from industrial and municipal sources. The data from the Netherlands are based on detailed estimations and measurements from over 700 individual industries. The data are extrapolated to Denmark and EU-15 by use of GDP. The number of decimals does not reflect the precision of the data. The uncertainties are discussed below.

1 PAH: Polycyclic Aromatic Hydrocarbons. van der Auweraert et al. (1996) report emissions of PAH to water as the sum of 6 individual and non-specified compounds.

2 DRINS: Common name for the group of commonly used cyclodien insecticides: Aldrine, dieldrine and endrine.

3 PCB: Polychlorinated Biphenyl Compounds

The estimate covers only selected prioritised industrial pollutants. Moreover, the estimated ecotoxicity potential is based only on substances where equivalency factors (EF) are published by Hauschild et al. (1998). For a few additional organic substances, the Water Quality Standards issued by the Danish EPA were used for the estimation of the ecotoxicity potential; see Table 10-6.

Table 10-6
Estimated ecotoxicity potential (EP) for organic toxic substances emitted to the aquatic environment.

1 The estimates are based on equivalency factors (EF) according to Hauschild et al. (1998), except for aliphatic substances where the ecotoxicity has been assumed to equal that of crude oil.

The background data are included in Appendix B.1.

10.4.2.3 Discussion

The estimated ecotoxicity potential includes only approximately half of the substances presented in Table 10-5 (see Appendices B.1 and B.2). Aliphatic substances account for the major part of the released compounds in Table 10-5. No EF is, however, available for this group of substances, but if the ecotoxicity is assumed to be equivalent to the toxicity of crude oil, the aliphatic compounds will contribute with 66% of the chronic toxicity potential and 18% of the acute toxicity potential. The chronic and acute ecotoxicity potentials for EU would in this case be 1.89*10¹³ m³/yr. and 1.16*10¹² m³/yr., respectively. These figures are used in the calculation of the normalisation reference as they are assumed to provide a more consistent result.

The Danish emission data presented above can be compared with reported releases of benzene, toluene, and xylenes via wastewater (Hansen 1995). The reference covers only selected industrial sources and thus gives only a rough picture of the releases. The author reported releases of benzene <1 tonnes/yr., and releases of toluene and xylenes at 20 tonnes/yr. and >10 tonnes/yr., respectively. The low emission reported for benzene may be explained by the fact that fuel is not included in the estimates. As for toluene the reported emission is about 9 times lower than the figures for Denmark presented in Table 10-5.

The uncertainties of the estimated effect potentials can be validated by comparing with measured emission data. In Table 10-7 values for the release of selected organic pollutants in the UK calculated by extrapolation from NL data are compared with measured riverine and direct inputs reported by the DETR (1999). The figures show considerable differences. The estimated emission of trichloroethane is 10 times higher than the highest values reported by the DETR. Also the estimated emissions of pentachlorophenol are a factor of 4-5 times higher than the measured riverine inputs.

The differences may partly be explained by the uncertainties introduced by extrapolation and partly by the fact that emission data based on measured riverine inputs underestimate the actual emissions, as biodegradation, evaporation, and adsorption will reduce the concentrations of many organic substances in the water phase between the point of emission and the monitored sampling point.

In addition to the organic substances discussed above measured releases of selected metals in the UK are compared with extrapolated values in Table 10-7. The values based on riverine inputs reported by the DETR are generally a factor of 3-10 higher than the estimated figures. It should be stressed that data on heavy metals based on riverine inputs include diffuse sources and natural background levels and therefore tend to overestimate the emissions from man-made sources. Moreover, unlike most organic substances, metals do not degrade or evaporate from aquatic environments.

From these data it is concluded that an extrapolation from NL data to other European countries seems to give uncertain but useful estimates of the emission to the aquatic environment.

Table 10-7
Data on emission to the aquatic environment of selected organic and
inorganic substances. The values reported by DETR are based on inputs
from point sources and riverine inputs (DETR 1999). The extrapolated
values are based on data from the Netherlands (van der Auweraert et al.
1996) extrapolated by use of GDP.

1 Low values: Concentrations below detection limits are set to zero. High values: Concentrations below detection limits are considered to equal the detection limits.

The presented ecotoxicity potential for organic pollutants to the aquatic environments is associated with a number of uncertainties:

• In general, there are very few data on emission of organic toxicants to the aquatic environment. The most extensive data compilation is from the Netherlands (van der Auweraert et al., 1996), which is used here. Of the parameters included in Table 10-5, EF are available for only about half of the substances. As discussed above the emission of aliphatic compounds may very well contribute with over half of the actual ecotoxicity potential released to the aquatic environment in Europe. Because of lack of information on the type of substances included in this group as well as missing effect factors, the aliphatic compounds are not included in the estimated ecotoxicity potential presented here. Consequently, the estimates should be regarded as minimum values of the release of toxicants to the aquatic environment.
• There are considerable differences in the composition of the industrial sector between countries. This is likely to bias the estimated ecotoxicity potential. As DK has relatively few chemical industries, the figures for DK are probably overestimated.
• There are differences in the wastewater treatment techniques applied in different European countries and thus the retention of organic pollutants in the treatment facilities. In countries like Germany, the Netherlands, Denmark, and Sweden two- or three-step wastewater treatment techniques are used, which retain organic and inorganic pollutants more efficiently than more simple techniques in the Mediterranean region. Consequently the estimated releases from these countries are probably underestimated.

10.4.3 Oil extraction and spills

10.4.3.1 Data sources

Oil extraction, refineries, and sea transport contribute significantly to the pollution of the marine environment. Data on emissions from refineries and production facilities in the North Sea are reported by EUROSTAT (1998). The data include emission from land and sea based on point sources including refineries, off shore oil extraction facilities, spills from handling of oil from terminals, etc. as well as legal spills from ships. The data do not include emissions from the point sources discussed above, i.e. wastewater emissions from industries and WWTP, as well as accidental spills from tankers, because accidental emissions in general are not included in the normalisation reference. Spills from tankers are registered by the International Tankers Organisation (ITOPF 1999) and may contribute on a yearly basis with quantities that are comparable in size or higher than all other sources together. Furthermore, data on emissions to the Mediterranean sea are not included.

10.4.3.2 Results

The data on releases of oil and crude oil etc. are presented in Table 10-8.

Table 10-8
Emissions of crude oil etc. from refineries, off-shore production facilities in the
North Sea, and legal discharges from ships. Accidental spills are not included.

1 The estimates are based on calculated equivalency factors (EF) as defined in Hauschild et al. (1998). See discussion below.

2 EUROSTAT (1998).

EP Ecotoxicity potential

The ecotoxicity potential from oil is calculated on the basis of a Predicted No-Effect Concentration (PNEC) for acute toxicity to aquatic organisms corresponding to 0.6 mg/l and a PNEC for chronic toxicity of 0.01 mg/l based on data for crude oil (IUCLID, 1996). The values are thus based on more recent data than used by Hauschild et al. (1998). The corresponding equivalency factors are: etwa = 1.67 m³/g and etwc = 100 m³/g. Crude oil is here regarded as slowly degradable in the marine environment although some fractions may degrade more rapidly or evaporate from the water phase. The resulting ecotoxicity potential is shown in Table 10-8.

10.4.3.3 Discussion

The estimated release of oil is associated with a number of uncertainties:

• The Mediterranean Sea is not included in the reported emissions.
• Accidental spills are a significant source, which according to the applied methodology is not included in the present evaluation. The reported yearly spills from the International Tankers Organisation (ITOPF, 1999) show average spills from 1987-1997 ranging 9,000 - 435,000 tonnes on a world basis with an average of 147,000 tonnes/yr. In 1994 the spills in European seas were about 25,000 tonnes, i.e. a volume comparable with the non-accidental emissions in the North Sea.

10.4.4 Antifouling

10.4.4.1 Data sources

Antifouling paints released from ships are a significant source for toxic substances released to the marine environment. Antifouling agents for commercial ship transport are normally based on the highly toxic tributyltin-compounds (TBT). The emission of tin to the Danish marine environment is estimated to be 0.6-4.9 tonnes TBT/yr. (DEPA 1997b). It has not been possible to identify other data sources.

10.4.4.2 Results

The release of TBT to the Danish marine waters is extrapolated to a European level by comparing the size of the Danish water area (approx. 43,000 km²) with the European water area (20% of the total area = 809,000 km² ). The figures should be regarded as a rough estimate of the release of organotin compounds from antifouling paints.

The Danish EPA has set a Water Quality Standard (WQS) at 0.001 mg/l of bis-tributyltiNO_xide (TBTO) corresponding to 0.00097 mg TBT/l. The equivalency factor for tributyltin used here is based on the Danish WQS (Danish Ministry of Environment, 1996). Table 10-9 shows the estimated equivalency factors based on these data.

Table 10-9
Ecotoxicity potential for organic tin-compounds (as tributyltiNO_xide, TBTO)
released from antifouling paint to the Danish marine environment.

1 Emission estimates from DEPA (1997b). Low = low end of the estimated range. High = high end of the estimated range.

2 The chronic equivalency factor for organotin is based on the water quality standards according to the Danish statutory order 921/1996 (Danish Ministry of Environment, 1996). The acute equivalency factor is a factor of 10 lower than the chronic factor.

3 Estimates for EU-15 are based on the area of marine water: Marine area in DK = approx. 43,000 km², marine area in EU-15 is 20% of the total area (approx. 809,000 km²).

EF Equivalency factor.

EP Ecotoxicity potential.

10.4.4.3 Discussion

The emission of organotin compounds from antifouling paints is based on a rough estimate of the marine releases in Denmark. This figure is extrapolated to a European level by use of the water area. The uncertainty of the estimate depends on the size of the traffic through the Danish marine areas compared to that of other European waters and the size of the area included in the estimates (in this report calculated as 20% of the total EU-15 area).

Because of the relatively large contribution of this source and the high uncertainty of the estimate, it is recommended to validate these figures further.

10.4.5 Atmospheric depositions

10.4.5.1 Data sources

The atmospheric deposition of toxicants to the aquatic environment is estimated according to the principles described in Hauschild et al. (1998). A discussion of the available data and the methods used for the estimation of the normalisation reference is found elsewhere in this report.

10.4.5.2 Results

The estimated deposition to the aquatic environment is shown in Table 10-10. The background data are included in Appendix C.

Table 10-10
Estimated contribution of toxic substances from deposition.

10.4.5.3 Discussion

The estimated ecotoxicity potential is primarily based on the deposition of metals and includes only the organic toxicants where effect factors are available. The estimate should therefore be regarded as a minimum level.

10.5 Normalisation reference - Terrestrial environment

The estimated releases of toxic substances to the terrestrial environment include the same types of sources as evaluated by Hauschild et al. (1998): Pesticides, agricultural use of sewage sludge, and atmospheric depositions. The emission types and data references included are presented in Table 10-11.

Table 10-11
Emission types and selected references used for the estimation of emissions to
the terrestrial environment.

10.5.1 Use of pesticides

10.5.1.1 Data sources

The dominating source of toxicant emission to the terrestrial environment is the agricultural use of pesticides. Statistics on the use is available from EEA (EEA 1998), OECD (1997) and from the national EPA's, e.g. DEPA (1997a). The toxicity pressure from pesticides depends on the toxicity of the individual active ingredient used and the number of applications recommended for different crop types. The large number of pesticides used makes such an estimate very complex.

For this reason the approach previously used by Hauschild et al. (1998) has been applied in the present report with some modifications.

The Danish data on use of pesticides are relatively detailed and allow calculations of the number of applications used for each of the main categories of pesticides (as active ingredients): Herbicides, fungicides, and insecticides. It is possible for each of these types to calculate an application factor expressing the average number of applications per ha for the different types of pesticides. The toxicity pressure expressed as the number of applications multiplied by the size of the treated area can then be estimated from the use of pesticides in the different countries.

10.5.1.2 Results

The estimated toxicity potential applied with the use of pesticides is presented in Table 10-12. The background data are presented in Appendix D.

Table 10-12
Estimated ecotoxicity potential for use of pesticides.

1 Use of pesticides (active ingredients): Danish data for 1994 from DEPA (1997a). European data for 1995 from OECD (1997).

10.5.1.3 Discussion

The estimated ecotoxicity potential is associated with a number of uncertainties:

• The differences in toxicity of the pesticides are not considered, i.e. the equivalency factor is based on a very rough estimate of a common PNEC value for all pesticides.
• Differences in application rates and praxis, crop types, climatic conditions, and national regulations are not considered.

10.5.2 Sewage sludge used for agricultural purposes

10.5.2.1 Data sources

Large quantities of sewage sludge are applied as agricultural fertiliser in most European countries. The normalisation reference estimated by Hauschild et al. (1998) was based on the content of heavy metals and tensides only. Since then extensive studies have made more comprehensive data available on the contents of organic pollutants in sewage sludge (Tørsløv et al. 1997).

These data are used in the present report for the estimation of the environmental release of toxicants via sewage. Data for use of sludge in agriculture in the European countries are derived from a study from 1994 by Hall and Dalimier (1994).

10.5.2.2 Results

The resulting EP from the use of sludge in agriculture is presented in Table 10-13. The background data are found in Appendices E.1 and E.2.

Table 10-13
Ecotoxicity potential from sewage sludge used in agriculture.

1. Sewage sludge used in agriculture. Data from DEPA (1998), OECD (1997),
   and Hall and Dalimier (1994).
2. Ecotoxicity potential calculated from the contents of toxicants in sludge
   (Tørsløv et al. 1997 and Hauschild et al. 1998). Additional equivalency
   factors derived from Jensen and Folker Hansen (1995).

10.5.2.3 Discussion

The ecotoxicity from the application of sewage sludges in agriculture is based on Danish data for contents of toxicants in sludge. These figures are in agreement with reported values for Swedish sludges but should be regarded as a low estimate of the contents of sludge from more heavily industrialised European regions. In addition the content of toxicants will depend on the design of the treatment facility, for example the hydraulic retention time and sludge age. Moreover, only a limited number of toxic substances are included in the estimate. By focusing on the dominating toxicants this error is minimised, but the estimate should be regarded as a realistic minimum of the ecotoxicity potential.

The overall contribution of sewage sludge is, however, small compared to other terrestrial sources.

10.5.3 Atmospheric depositions

10.5.3.1 Data sources

The atmospheric deposition of toxicants to the terrestrial environment is estimated according to Hauschild et al. (1998). A discussion of the available data and the methods used for the estimation is found in the section on human toxicity.

10.5.3.2 Results

The estimated deposition to the terrestrial environment is shown in Table 10-14. The background data are presented in Appendix C.

Table 10-14
Estimated contribution of toxic substances to the terrestrial environment from deposition.

10.5.3.3 Discussion

The atmospheric deposition contributes with about half of the ecotoxicity potential emitted to the soil environment in Europe. 96% of this contribution is caused by selenium. The deposition of selenium is twice the deposition of mercury and three times the deposition of cadmium, i.e. metals that are normally regarded as more serious pollutants. Nevertheless, the estimated toxicity potential for deposition of selenium on soil is 50 and 180 times higher than that for mercury and cadmium, respectively.

It is recommended to re-evaluate the equivalency factor of selenium.

10.6 Normalisation references

The data and estimates presented above are summarised in Table 10-15. In addition to the calculated ecotoxicity potential for DK and EU-15 an estimate of the ecotoxicity potential on a world basis is presented. The normalisation data for DK and EU-15 is discussed in the sections above.

Assuming correlation among acidification, GDP and ecotoxicity the worldwide normalisation reference is calculated by a simple extrapolation from the EU-15 data to a world basis by use of the Gross Domestic Products. Data for the emission of toxic substances to the environment was found for high-income countries only. Because of the lack of data for countries with lower per capita income it was not possible to differentiate between income groups in the extrapolation of releases of toxic substances. Thus the extrapolation presented here does not take the differences between countries with respect to degree of industrialisation, pesticide use etc. into consideration.

Table 10-15
Ecotoxicity potentials for emissions of toxic substances to the environment in Denmark and EU-15. A worldwide normalisation reference is calculated by extrapolation from EU-15 data by use of Gross Domestic Products.

Table 10-15 shows the annual contribution of the individual emission types and types of substances to the overall ecotoxicity potential (EP) in m³ released to the environment. By using the extrapolation method proposed in chapter 3, Development of normalisation references for different geographic areas, the worldwide normalisation reference for ecotoxicity can be estimated to 7.95*10⁴ m³/capita/year (etwc), 6.57*10³ m³/capita/year (etwa), and 2.78*10⁵ m³/capita/year (etsc). These normalisation references are slightly above the references estimated by extrapolation of the effect potential.

The contribution to the aquatic environment is dominated by the release of organotin compounds from antifouling paints that contributes with over 70% of the total aquatic emissions in Denmark, and about 50% of the aquatic emissions in Europe. The EP for organotin is based on an emission to the Danish aquatic environment of organotin of 2.8 tonnes per year representing a range from 0.6-4.9 tonnes per year. If the lower end of this interval is used instead of an average value the contribution from organotin compounds is reduced to 37% of a total EP for chronic toxicity released to the Danish aquatic environment at 1,66*10¹² m³/yr. In this case metal emitted from point sources will contribute with 47%. If the high end of the interval is used organotin will contribute with 83% of the emitted EP and metals with only 13%.

Emission of metals to the aquatic environment accounts for 40% of the emission in EU-15 and 20% of the Danish emissions. Copper contributes with 21% in EU-15 and with 14% in Denmark. Also zinc contributes significantly (9 and 3%, respectively).

The use of pesticides contributes with almost 100% of the EP to the Danish and EU-15 terrestrial environments. This holds true even if the contribution from the pesticide use is assumed to be 10 times lower than assumed in the estimates of the toxicity from this source. The second largest contribution to terrestrial toxicity is thus the atmospheric deposition, mainly caused by selenium. According to Hauschild et al. (1998) selenium has a very high equivalency factor for chronic toxicity in soil, when emitted to the air (106 m³/g), compared to metals like cadmium (1.8 m³/g) and mercury (5.3 m³/g). This is caused by a combination of a relatively low partitioning coefficient for selenium in soil and a high toxicity.

10.7 Comparison with the previously used normalisation reference

In Table 10-16 the estimated normalisation references are compared with the values for 1990-1992 calculated by Hauschild et al. (1998).

Table 10-16
The estimated total ecotoxicity normalisation reference for Denmark compared to the values for the years 1992-1994 in Hauschild et al. (1998).

ETWC: Ecotoxicity Potential for chronic effects on aquatic organisms.

ETWA: Ecotoxicity Potential for acute effects on aquatic organisms.

ETSC: Ecotoxicity Potential for chronic effects on soil organisms.

The EP for the aquatic environment is about 1.5 times higher than estimated in 1990-1992. Considering the uncertainties involved, the estimates are, however, comparable in size. The main differences are the contribution from organotin compounds to the aquatic environment and the lower deposition of heavy metals in the present estimate compared to the earlier estimates.

The present estimate for the terrestrial environment is considerably higher than earlier reported. This is mainly caused by a higher estimated ecotoxicity potential for pesticides (a factor of 65 higher).

It should be stressed, however, that the observed differences are mainly caused by methodological differences rather than changes in the environmental releases.

10.8 Evaluation of uncertainties

The uncertainties discussed above are summarised in Table 10-17. The uncertainties are scored in three categories: "Low", i.e. an uncertainty expected to be considerably lower than one order of magnitude, "medium", i.e. an uncertainty expected to be up to one order of magnitude, and "high", i.e. an uncertainty expected to be higher than one order of magnitude. The uncertainties are due to both the applied methodology and limitations of data. It should be stressed that these uncertainties are subjective and based on the author's experiences obtained during the project. Within the frame of this project it was not possible to estimate the size of the uncertainties more precisely.

The overall uncertainty of the normalisation reference is expected to be high as the uncertainties of the dominating sources of toxicant releases in the aquatic as well as the terrestrial environments are high, i.e. the release of organic tin compounds from antifouling paints used on ships and from the use of pesticides in agriculture.

Table 10-17
Summary of the expected uncertainties of the presented ecotoxicity potentials of the individual sources of toxicants. It is stressed that the uncertainties are based on the author's subjective impressions and do not represent a quantitative estimate.

10.9 Recommendations

Most of the data sources used in the estimates are linked to international or national statistics, which are regularly updated. It should therefore be relatively simple to update the calculations. The two dominating sources of toxicant release: Pesticides and tributyltin compounds used in antifouling paints are, however, based on rather rough assumptions and non-validated data. Statistics on the use of pesticides are available on a yearly basis, but the estimated ecotoxicity potentials are based on non-validated assumptions. Data on the release of tributyltin are not available, and the presented figures are based on rough estimates of the release to the Danish aquatic environment. It is recommended that the ecotoxicity potentials for these emission types are further validated.

The estimated ecotoxicological impact is based on relatively limited data on environmental releases of selected organic and inorganic substances and should in general be regarded as a minimum estimate because it was impossible to include all types of sources, and only some of the substances that are known to be emitted are included in the presented estimates.

It is recommended to validate the estimated ecotoxicity potential by comparison with chemical consumption data combined with release factors. This will probably represent a maximum estimate of the actual release levels. It was, however, not possible within the frame of the present project to perform this validation.

10.10 References

DEPA (Danish Environmental Protection Agency) 1995, Punktkilder 1994. Vandmiljøplanens overvågningsprogram (point sources 1994, the monitoring programme of the Aquatic Environment Plan). Information No. 10. In Danish.

DEPA (Danish Environmental Protection Agency) 1996, Massestrømsanalyse for kviksølv (mass flow analysis of mercury). Environmental Project No. 344. In Danish.

DEPA (Danish Environmental Protection Agency) 1997a, Bekæmpelses-middelstatistik 1996 (statistics for pesticides 1996). Information No. 10. In Danish.

DEPA (Danish Environmental Protection Agency) 1997b, Massestrømsanalyse for tin med særligt fokus på organotinforbindelser (mass flow analysis of tin focusing on organotin compounds). Working report No. 7. In Danish.

DEPA (Danish Environmental Protection Agency) 1998, Affald 21 Udkast til affaldsplan 1998-2004 (draft for waste plan). Draft for a hearing of 25th September, 1998. In Danish.

DETR (1999) Department of the Environment, Transport and the Regions. Environmental statistics. http://www.detr.gov.uk.

EUROSTAT F₃ Environment Unit 1998, Towards environmental indices: A first exercise. Volume 1: Background report - final. Consultora Ambiental, S.L., Spain.

EEA 1998, Europe's Environment: The Second Assessment. Eurostat, European Commission, European Environment Agency. Office for Official Publications of the European Commission, Luxembourg.

Grüttner, H. & Neergaard Jacobsen, B. 1994, Miljøfremmede stoffer i renseanlæg. Belastning og renseeffekt (xenobiotic substances in wastewater treatment plants, load and effect of treatment process). Environmental project No. 278. In Danish. Danish Environmental Protection Agency.

Grüttner, H., Vikelsøe, J. & Pritzl, G.1996, Miljøfremmede stoffer i spildevand og slam. Massestrømsanalyser for renseanlæg (xenobiotic substances in municipal wastewater and sludge, mass flow analyses of WWTP). Environmental project No. 325. In Danish. Danish Environmental Protection Agency.

Hall, J.E. & Dalimier, F. 1994, Waste management - sewage sludge. Part 1. Survey of sludge production, treatment, quality and disposal in the European Union. Report No. EC 3646(P). EC reference No. B4-3040/014156/92.

Hauschild, M., Wenzel, H., Damborg, A. & Tørsløv, J. 1998, Ecotoxicity as a criterion in the environmental assessment of products in Environmental assessment of products. Volume 2 Scientific background eds. Hauschild. M. & Wenzel. H. London: Chapman & Hall.

Hauschild, M. & Wenzel, H. 1998, Environmental assessment of products. Volume 2. Scientific background. Chapman & Hall, Thomson Science, London, UK.

Holmegaard Hansen, J. 1995, Nationale og industrielle emissioner af 38 stoffer (national and industrial emissions from 38 substances). Working report No. 64. In Danish. Danish Environmental Protection Agency.

ITOPF 1999, Objective technical advice, expertise, assistance and information on effective response to ship-source pollution. Historical data. http://www.itopf.com. The International Tanker Owners Pollution Federation Limited.

IUCLID 1996, International Uniform Chemical Information Database. Existing chemicals. 1 ed. European Chemicals Bureau. Environment Institute, Ispra, Italy.

Jensen, A. & Markussen, J. 1993, Forbrug af og forurening med cadmium (consumption of cadmium and pollution by cadmium). Environmental Project No. 213. In Danish. Danish Environmental Protection Agency.

Jensen, J. & Folker-Hansen, P. 1995, Soil quality criteria for selected organic compounds. Working report No. 47. Danish Environmental Protection Agency.

Jepsen, S.-E. & Grüttner, H. 1997, Miljøfremmede stoffer i husholdningsspildevand. Måleprogram for udvalgte stoffer (xenobiotic substances in domestic wastewater, measuring programme for selected substances). Environmental Project No. 357. In Danish. Danish Environmental Protection Agency.

Lassen, C., Drivsholm, T., Hansen, E., Rasmussen, B.& Christiansen, K. 1996a, Massestrømsanalyse for nikkel. Forbrug, bortskaffelse og udslip til omgivelserne i Danmark (mass flow analysis of nickel, consumption, disposal, and emission to the environment in Denmark). Environmental project No. 318. In Danish. Danish Environmental Protection Agency.

Lassen, C., Drivsholm, T., Hansen, E., Rasmussen, B. & Christiansen, K. 1996b, Massestrømsanalyse for kobber. Forbrug, bortskaffelse og udslip til omgivelserne i Danmark (mass flow analysis of copper, consumption, disposal, and emission to the environment in Denmark). Environmental project No. 323. In Danish. Danish Environmental Protection Agency.

Lassen, C. & Hansen, E. 1996, Massestrømsanalyse for bly. Forbrug, bortskaffelse og udslip til omgivelserne i Danmark (mass flow analysis of lead, consumption, disposal, and emission to the environment in Denmark). Environmental Project No. 327. In Danish. Danish Environmental Protection Agency.

Madsen, T., Gustavson, K., Samsøe-Petersen, L., Simonsen, F., Jacobsen, J., Foverskov, S. & Mørk Larsen M. 1998, Kortlægning og vurdering af antibegroningsmidler til lystbåde i Danmark (survey and assessment of antifoulants for pleasure craft in Denmark). Environmental project No. 384. In Danish. Danish Environmental Protection Agency.

OECD 1997, Compendium of environmental data. OECD Publications, Paris, France.

Tørsløv, J., Samsøe-Petersen, L., Rasmussen, J.O. & Kristensen, P. 1997, Use of waste products in agriculture. Contamination level, environmental risk assessment and recommendations for quality criteria. Environmental project No. 366. Danish Environmental Protection Agency.

UBA (Umwelt Bundes Amt) 1999, Current publications. http:/www.umweltbundesamt.de.

van der Auweraert RJK, Berdowski JJM, Jonker WJ, Verhoeve P 1996, Emissies in Nederland Bedreijfgroepen en Regio's 1994 en Rammen 1995. Publicatiereeks Emissieregistratie Nr. 33. `s-Gravenhage: Hoofdinspectie Milieuhygiëne /IPC 680.

Appendix A: Emissions to the aquatic enironment, metals

Austria

References

1) Based on van der Auweraert et al. (1996)

Belgium

References

1) Eurostat (1998)

Denmark

References

Danish Environmental Protection Agency 1995

Danish Environmental Protection Agency 1996

Grüttner and Neergaard Jakobsen 1994

Grüttner et al. 1996

Jensen and Markussen 1993

Lassen and Hansen 1996

Lassen et al. 1996a

Lassen et al. 1996b

Finland

References

1) Eurostat (1998)

France

References

1) Eurostat (1998)

Germany

References

1) Eurostat (1998)

Greece

References

1) Based on van der Auweraert et al. (1996)

Ireland

References

1) Eurostat (1998)

Italy

References

1) Based on van der Auweraert et al. (1996)

Luxemburg

References

1) Based on van der Auweraert et al. (1996)

Netherlands

References

1) Based on van der Auweraert et al. (1996)

Portugal

References

1) Eurostat (1998)

Spain

References

1) Eurostat (1998)

Sweden

References

1) Eurostat (1998)

UK

References

1) Eurostat (1998)

EU-15

Appendix B.1 Emissions to the aquatic environment, organic substances - Denmark

Based on van der Auweraert et al. (1996)

Click here to see the Table.

Appendix B.2: Emissions to the aquatic environment, organic substances - EU-15

Based on van der Auweraert et al. (1996)

Click here to see the Table.

Appendix C: Emissions to the aquatic environment, atmospheric deposition

Appendix D: Emissions to the terrestrial environment, pesticides

Equivalency factor based on the principles used in Hauschild et al. (1998)

Click here to see the Table.

Appendix E.1: Emissions to the terrestrial environment, sewage sludge applied in agriculture - Denmark

References

1. Hauschild & Wenzel (1998).

2. DEPA (1995).

3. DEPA (1998).

Appendix E.2: Emissions to the terrestrial environment, sewage sludge applied in agriculture - EU-15

References

Hauschild et al. (1998)

DEPA (1995).

DEPA (1998).

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