Research Articles
Monitoring PAHs and Heavy Metals
Research Articles
Monitoring Polycyclic Aromatic Hydrocarbons (PAHs) and Heavy Metals in Urban Soil, Compost and Vegetation Markus Niederer, Annemarie Maschka-Selig, Christopher Hohl Kantonales Laboratorium Basel-Stadt, Postfach, CH-4012 Basel, Switzerland
Corresponding author: Dr. Markus Niederer
Abstract Samples of urban surface soil, composts, leaves from avenue limetrees and grass from park areas of the city of Basel (Switzerland) were analysed for polycyclic aromatic hydrocarbons (PAHs) and heavy metals. Generally, significant lower levels of PAHs (10 times lower) and heavy metals (3 - 70 times lower) were found in vegetation samples than in composts or soils. The concentrations of PAHs in soil and compost samples were in the same order of magnitude although 10 - 100-times higher in comparison to data given for rural soils in other studies, whereas heavy metal contents in urban soils and composts were 2 - 3 times higher than in rural samples. Using multivariate statistical analysis, it was possible to define similarities or special characteristics of single substances or substance groups in a given matrix reflecting their chemical properties and providing information on their specific emission sources.
1
Introduction
Polycyclic aromatic hydrocarbons (PAHs) and heavy metals are frequently found in various environmental samples as a result of anthropogenic contamination and/or natural processes [1]. In Switzerland, soil monitoring programmes concerning heavy metals have become routine and are based on federal legislation [2]. In contrast, comparatively little is known about environmental aspects and levels of PAHs in soil even though the combination of carcinogenic properties of certain congeners and their physico-chemical properties such as lipophilicity, stability and nonvolatility, as well as their ubiquitous distribution in the environment by various combustion sources, would define them as priority pollutants for soil monitoring programmes. Moreover, research concerning the influence of soil PAHs on growth of microorganisms [3] and senescence of plants [4] both show a negative impact. In this study, we report on current levels of PAH and heavy metal concentrations in urban samples (soil, compost, vegetation) from the city of Basel (200,000 inhabitants) and on the use of multivariate statistics (Factor Analysis) as a useful method to describe similarities or special characteristics of single substances or substance groups in the matrices. Furthermore, a comparison of theoretical pollutant levels of compost calculated by using data of concentrations found
ESPR-Environ. Sci. & Pollut. Res. 2 (2) 8 3 - 8 9 (1995) 9 ecomed publishers, D-86899 Landsberg, Germany
in grass and leaves with data of actual compost samples, as well as a comparison of the PAH profiles in different matrices, are included.
2
2.1
Experimental
Samples
Soil samples were taken from 21 sites at a depth of 0 - 20 cm as described in [5]. Compost samples came from 16 public district composting sites which mainly consist of kitchen refuse and garden litter. Leaf samples were taken from avenue lime-trees at 10 sites and grass samples from park areas or playgrounds for children (total 10 sites). Samples were stored at - 20 ~ until PAH-analysis or dried at 40 ~ and homogenised for heavy metal analysis [5].
2.2
Determination of PAHs
Frozen samples (vegetation: 10 g, soil and compost: 40 g fresh weight) were spiked with internal standards (deuterated pyrene-dl0, benzo[a]pyrene-d12, Cambridge Isotope Laboratories) for quality control of the sample preparation steps and calibration. Thereafter, samples were extracted with water-acetone-hexane (1:1 : 1, v/v / v) by shaking for 3 hours at room temperature. After prefiltering, the extract was separated in a separatory funnel and the organic phase cleaned up using silicagel column chromatography with cyclohexane as an eluent. The final eluate was concentrated by rotary evaporator to minimal volume and resuspended in toluene. Separation and identification of PAHs (-* Table 1) was performed by gas chromatography-mass spectrometry (Carlo Erba HRGC 5160, Fisons and ITD 700, Finnigan MAT) under the following conditions: DB-5MS (J&W) fused silica column (30 m x 0.25 mm I.D., 0.25/2m film) with a retention gap (0.5 m x 0.32 mm I.D., deactivated) used with on column injection of 0.5/21; temperature programme 90 ~ (lmin.)-(30 ~ ~ ~ ~ carrier gas (helium) 150 kPa; mass range 101 - 2 9 8 amu, full scan mode (sec./scan = 0.5).
83
Monitoring PAHs and Heavy Metals
Research Articles
Table 1: Identification of P A H separated by gas chromatography-mass spectrometry (GCMS) on the basis of retention times and mass Compound
Naphthalene Acenaphthylene Acenaphthene Fluorene Phenanthrene Anthracene Fluoranthene Pyrene Benzo[a]anthracene Chrysene a Benzo[b]fluoranthene a Benzo[k]fluoranthene Benzo[e]pyrene b Benzo[a]pyrene a Indeno[123-cd]pyrene a Dibenzo[ah]ant hracene a Benzo[ghi]perylene PAH (sum of 16)
Abbrev.
Nap Acnyl Acna Fluo Phen/an Phen/an Fluant Pyr Bzaan Chry Bzfl Bzfl Bep Bap Ind Dibzan Bzper ~ 16PAH
Retention
Mass
Mass for
itime (min)
(m/z)
GCMS Quantification
3.51 5.45 5.70 6.37 7.70 7.70 9.58 10.00 12.93 13.07 17.43 17.43 18.93 19.22 27.98 28.43 30.52 -
128 152 154 166 178 178 202 202 228 228 252 252 252 252 276 278 276 -
1 2 6 - 130 1 5 0 - 153 1 5 4 - 156 163 - 167 176 - 179 176-179 200 - 204 200 - 204 225 - 230 225 - 230 250 - 253 250 - 253 250 - 253 276 278 274 - 278 -
carcinogenic in animal experiments b not quantified, used for quality control a
For quantitation, 16 PAHs (Supelco, US EPA SW-846) were used for calibration in amounts ranging from 0.04 to 100 ng (correlation coefficients r > 0.995). Corrections were based on the internal pyrene-dl0 standard. Recovery rates of pyrene-dl0 and benzo[a]pyrene-d12 were about 90 % and 85 %, respectively. Reproducibility of three soil sample replicates expressed as mean relative standard deviation of PAHs was 1 1 % and the calculated limits of detection were approx. 3/~g/kg dwt. 2.3
Determination of heavy metals
Sample aliquots (approx. 0.5 g dry weight) of compost, leaves and grass were digested with a microwave system (MLS 1200, Milestone) using 65 % (w/w) nitric acid, 30 % (w/w) hydrogen peroxide and water. In the case of soil, extraction of 10 g dwt with 2 M nitric acid at 95 ~ was carried out according to the Swiss standard procedure [5]. Analysis of lead (Pb) in plants, nickel (Ni) and cadmium (Cd) was performed by Graphite Furnace-AAS (atomic absorption spectrometry, Zeemann 3030 Perkin-Elmer), Pb in soil and compost, copper (Cu) and zinc (Zn) by Flame-AAS (Perkin-Elmer 2380), and mercury (Hg) by Hg-cold vapour techniques (MHS-20, Perkin-Elmer). Reproducibility of compost replicates (n = 10) was 20 % for Pb, Cd and Cu, and 13 % for Hg. Zn and Ni were not tested. Limits of detection (mg/kg dwt) in plants, in soil and compost were 0.2 and 6.5 (Pb), 0.05 (Cd), 0.04 (Hg), 9.0 and 2.6 (Cu), 18 and 6.8 (Zn), 4.2 (Ni), respectively.
2.4
Multivariate statistical analysis
The Factor Analysis (STATISTICA for windows, StatSoft, Inc., Tulsa OK) procedure extracts principal components of 84
variables of interest and was used in our study to define groups of high correlated substances in soil and compost by linear combination [6]. In the case of grass and leaves pollutant levels, were too low and the analytical error too high to apply Factor Analysis.
3 3.1
Results and Discussion Comparison of pollutant levels in grass, leaves, composts and soils
Generally, on the base of dry weight (dwt) significant lower levels of PAHs (10 times lower) and heavy metals ( 3 - 7 0 times lower) were found in vegetation samples than in compost or soil ( ~ Fig. 1). For vegetation samples and soil, these differences can be mainly explained by the factor exposure time. Leaves and grass most likely reflect pollutant levels caused by airborne immission during part of the vegetation period between shooting and sampling (weeks to months). Soils, on the other hand, accumulate PAHs and heavy metals over decades.Their pollutant levels can therefore be strongly influenced by former immission situations no longer corresponding to current air pollution levels. In addition, we have to take into consideration that local factors other than airborne immission, e.g. use of fertilizers, can lead to soil contamination. In the case of compost, one would expect pollutant levels which are determined by levels of the major constituents being kitchen refuse (e.g. spoiled fruit, vegetable, coffee grounds) and garden litter (e.g. grass and leaves). Of these two categories, kitchen refuse can certainly be excluded as a major source of heavy metals and PAHs in compost, because of well etablished food quality controls. On the other hand, leaves and grass car~ accumulate large amounts of airborne pollutants due to their high specific surface (surface to weight ratio). For calculating theoretical pollutant levels in compost, we therefore assumed that our final compost originated exclusively from grass and leaves and that 1 kg of fresh vegetation material produces 0.6 kg of compost [7]. Theoretical concentrations obtained ranged between 9 % (Pb), 45 % (PAHs), 48 % (Cd), 63 % (Zn), 68 % (Cu) to a maximum 7 1 % (Hg) of the actual mean levels and hence explain only a fraction of the concentrations found. 3.2
Comparison of PAH and heavy metal concentrations
in soil Care has to be taken when comparing soil data from different studies. Differences e.g. in sampling depths and analytical procedures bias the pollutant concentrations obtained. In the case of PAHs, where the number of analysed congeneres vary, total amounts refered to in other studies are therefore based on our rough estimation for 16 PAHs if necessary. The mean total concentration of PAHs found in our soil samples are about two and four times higher than amounts found in other urban soils ( ~ Table 2). PAH levels of some of our sampling sites were even in the same range as those mentioned for soils near highways and, therefore, an inhibition effect on plant growth by plant hormones like PAHs cannot be excluded [4]. Much lower mean levels (10 to 100 times lower) are reported from rural and forest sites and, surprisingly, from sewage sludge ( ~ Table 2).
ESPR-Environ. Sci. & Pollut. Res. 2 (2) 1995
Research Articles
Monitoring PAHs and Heavy Metals
6O 50
400
160r-
I J
A
Box Plot of Lead
Box Plotof Copper
Box Plot of PAH (sum of 16) 140
+
350 C
120
o
300
i
~
40
E
+
E 20
100 8O
-F
I
4o
10
2~
I
60
100
2O leaves
grass
leaves
grass
compost
soil
0
~ leaves
Box Plot of Cadmium
Box Plot of Mercury
D
I.
L
80O
I O O
i
+
'
Fi
grass
compost
soil
Box Plot of Zinc
F
I
I
i 0.
"
50
soil
compost
200
E 150
600 o
O
E 0.
E, f
o----
"
400
E
200
=%
§ I
I
grass
leaves
compost
soil
leaves
grass
compost
soil
leaves
grass
compost
soil
Fig. 1"Box and whisker-plot of PAH and heavy metal concentrations in leaf samples of lime trees (n = 10), grass samples (n = ]tO), compost samples (n= 16) and soil samples (n= 21). Median ( t ) , 2 5 - 75 % percentile (~]) minimum-maximum value (I), outlier (o), extreme ( + )
Table 2: Comparison of soil PAH concentrations (mg/kg dwt) with other studies Study site (soils)
Urban (Basel,
n Number sample of PAH
21
16
Soil depth
0 - 20cm
PAH mean values 11.1_+11.9
CH) Urban (Bern,
Origin
Own
results 19
16
0 - 20cm
4.8_+4.5
[8]
4
8
0 - 3cm
[9]
3
10
0 - 20cm
11 12
16 27
0 - 20cm 0 - 10cm
4 27
4 6
0 - 20cm
1.3_+0.8 (2.6) a 0.2+0.0 (0.3) a 0.1 ___0.1 0.7_+0.5 (0.4) a 0.1 (0.4) a 0.4+0.4 (1.1) a
CH) Urban (Japan) Forest (Aargau, CH) Rural (CH) Rural (A) Rural (D) Sewage sludge (CH) Near highways (CH)
8
16
0 - 20cm
a Estimation for ~ 16PAH
ESPR-Environ. Sci. & Pollut. Res. 2 (2) 1995
21.0_+
[lO] [11] [12] [13] [14] [15]
Less caution has to be taken in comparing mean heavy metal concentrations from different studies in Switzerland due to standard analytical procedures [5]. Urban soils from Basel and Bern show similar mean (median) levels for all heavy metals (-* Table 3). The tendency of higher concentrations in Basel can be easily explained by the bigger size of the city. Differences between Swiss urban and rural sites are pronounced in the case of lead and zinc, but much less so for cadmium and copper. Data for German urban soils seems to represent much higher levels in general. However, due to unknown sampling depths and analytical procedures, an artefact cannot be ruled out. In both Table 2 and 3, the influence of highways on PAH and heavy metal (especially Pb) levels can be seen.
3.3
Comparison of PAH and heavy metal concentrations of compost
The heavy metal contents of 16 composting sites were determined on a half yearly basis over a period of 1.5 years (Aug. 90 - Feb. 92). The 4 consecutive values of the majority of sample sites showed relative standard deviations below 25 %. This is probably in the range of total analytical error and therefore a seasonal dependency cannot be seen. Due to high correlations with mercury ([12] and Fig. 4), the same has been suggested for PAHs which were only analysed in February 1992.
85
Monitoring PAHs and Heavy Metals
Research Articles
Table 3: Comparison of soil heavy metal concentrations (mg/kg dwt) with other studies. Median values of 0 - 20 cm soil depth and range of minima and maxima Study site CSoils) Urban (Basel, CH) Urban (Bern, 3H) Urban (D) b Rural (CH) rqear highways CH)
n sample
Pb
Cd
Cu
21
114 (23 - 366) 75 (27 - 350) 300 - 700 24 (14-41) a 94 (40 - 754)
0.37 (0.17-0.88) 0.32 (0.12-1.51) 0.9-2.1 0.23 (0.11 - 0.45)a 0.69 (0.28 - 2.47)
35 (18-121) 3O (8 - 2O0) 1-97 23 (9-61) a
73 77
237 18
Hg
Zn
Origin
0.3
143 (57 - 493) 109 (33-970) 140 - 600 56 (33 - 94) a 192 (78 - 906)
Own results
(0,1 - 1.0)
0.2 (0.1 - 20.0) 0 . 4 - 1.1
[8] [18] [17] [15]
a range including 80 % of values b amount of samples, median values and sampling depth are not known
In order to investigate possible regional differences within our study perimeter, we grouped data from composting sites of central and northern Basel (region A), which show high traffic and industrial density, and those from typical residential districts (region B). Mean pollutant levels in composting sites from region A where significantly higher for lead, cadmium, mercury and zinc (-* Fig. 2). Total PAH and Benzo[a]pyren~ mean levels are also higher in region A, but due to the enormous variance of levels of individual sites, the differences found were not statistically significant. The distribution of copper seems to be more or less homogeneous over all sites. In the case of nickel, the standard deviation for region B is too high for interpreting possible differences of mean values.
sites (-0 Table 4). In Basel we found similar PAHs values as in compost consisting of vegetation material originating from highway borders. More data is available in the case of cadmium, lead and zinc concentrations (-+ Table 5). The values found in composting sites of Basel are of the same order of magnitude as those reported from other urban regions. Comparing rural and urban compost, higher amounts of heavy metals can be found in urban sites, especially in the case of lead ( 2 - 4 times higher). Table 4: Comparison of compost PAH concentrations (mg/kg dwt) with other studies Study site Icomposts) Urban (Basel, ~H) Urban (Olten, ~H) Rural (CH) ,,Normal" Aargau, CH) Near highway IAargau, CH)
n sample
Origin
Number ]~PAH of PAH mean values
Own results [11]
16
16
5.5 ( 2 - 2 1 ) a
2
16
2.6
1 5
16 10
0.8 1.8 (3) b
[111 [18]
2
10
4.4 (7)b
[181
Min-Max b Estimation for Y.16PAH
=
Fig. 2: Differences of compost pollutants between city and industrial districts (region A: 8 composting sites) and residential districts (region B: 8 sites). Amount of PAH-samples: 1 per compost site ( = 8 per region), amount of anorganic samples: 4 per compost sites ( = 28 - 30 per region). Overall mean values in mg/kg dwt (= 100 %): 0.66 (Bap), 5.47 (]~ 16 PAH), 116.61 (Pb), 0.65 (Cd), 56.85 (Cu), 0.26 (Hg), 17.88 (Ni), 273.78 (Zn). * Significant (t-test, p>-
>>,
"1"
"T" -0.03
0 0
0.2
0.4
0.6
0.8
'1
-0.0"1
0,19
P A H s ( F a c t o r 1)
0.39
0,59
0.79
0.99
P A H s ( F a c t o r 1)
Fig. 4: Clusters (1 -3)and correlations (r) of analysed substances in soil (A) and compost (B)
Copper (3) is the only element which shows no correlation to other pollutants, neither in soil nor in compost. This special behaviour of copper can be explained by different copper specific input procedures: Abrasion of power lines of tramways or trains, and the use of copper containing plant sprays. Furthermore, the distribution of copper in airborne dust could also play a role because, in contrast to zinc, cadmium and lead, copper can sometimes dominate in coarse-grained dust fractions [23].
4
Conclusion
Compared to rural ("natural") conditions, elevated pollutant concentrations in soil and compost were predominantly found in the case of PAHs and lead. Both show a high affinity to soil particles under normal soil conditions and therefore are not readily bioavailable. Ingested amounts via the food chain, soil-plant or soil-plant-animal are too small to be of toxicological relevance for man. Hence, production restrictions on soil grown food, grazing bans and prohibition of using compost as a fertilizer are inadequate countermeasures in dealing with elevated, but not astronomically high, lead and PAIl concentrations in soil. In the case of compost, the ecological benefit of recycling kitchen refuse and garden litter outweighs the disadvantage of an additional soil pollution by this pathway, especially if decreasing future pollutant levels are taken into account due to enforcement of environmental laws. However, contamination levels in soils caused by decades of uncontrolled emissions are in an order of magnitude where destabilizing effects on the ecosystem, e.g. by disturbing plant growth due to hormonlike PAHs [4] or by upsetting microorganism populations vital for soil fertility [24], have to be taken into consideration and further monitoring is therefore indicated.
88
Analysing compost and vegetation can be seen as complementary to air and soil monitoring, representing intermediate phases between emission and immission. Our results for compost show differences between industrial regions with high density traffic and residential districts and are consistent with studies concerning the air pollution of Basel [25, 26]. Our calculation of theoretical pollutant concentrations in compost based on data for vegetation do not explain the analysed levels. The origin of levels in compost is hence not fully understand. Multivariate statistics is a useful method to extract similarities or special characteristics of pollutants in the respective matrix. Instead of obscure correlation tables, we can display simple graphics with groups of highly correlated substances, making interpretation of environmental data much easier. Acknowledgements We thank Theresa OTZ, Rita BOLLHALDER,Markus KALBERERand Nicole ACHERMANNfor their technical support in analysing heavy metals9
5
References
[1] F. SCHEFFER;P. SCHACHTSCHNABEL:Lehrbuch der Bodenkunde. 9 Ferdinand Enke Verlag, Stuttgart 1984, 271 [2] VSBo-Richtlinie: Verordnung fiber Schadstoffe im Boden. Anhang Art. 5 (1986) [3] N. T. EDWARDS:Polycyclichydrocarbons (PAH's)in the terrestrial environment - a review. J. Environ. Qual. 12:427 (1983) [4] M. BERTEIGNE;C. ROSE;J. GEP,ARD;P. DIZENGREMEL:Effects of polyaromatic hydrocarbons on the forest ecosystem and woody plants. Ann. Sci. For. 46, 561 (1989) [5] FAC: Methoden ffir Bodenuntersuchungen. Schriftenreihe der Eidgen6ssischen Forschungsanstalt ffir Agrikulturchemie und Umwelthygiene Liebefeld Nr. 5 (1989) [6] E. WEBER: Grundriss der bio]ogischen Statistik. VEB Gustav Fischer Verlag, Jena 1986, 464
ESPR-Environ. Sci. & Pollut. Res. 2 (2) 1995
Research Articles [7] [8] [9] [10]
[11]
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[16] [17]
K. FRICKE; T. TURK; H. VOGTMANN: Grundlagen der Kompostierung. EF-Verlag fiir Energie- und Umwelttechnik GmbH, Berlin 1990, 37 GSA: Stoffbelastung in der Agglomeration Ausserholligen St6ckacker/Bern. Untersuchungsbericht des Amtes ffir Gew~isserschutz und Abfaltwirtschaft des Kantons Bern (1994) T. SPITZER;S. KUWATSUKA:Residue levels of polynuclear aromatic compounds in urban surface soil from Japan. J. Chromatogr. 643, 305 (1993) A. KANZIG;M. WERFELI:Untersuchung von Waldb6den im Kanton Aargau auf die Belastung mit organischen Schadstoffen. Schlussbericht des Kantonalen Laboratoriums Aargau (1990) J. D. BERSET: Organische Fremdstoffe in der Landwirtscbaft: Verteilung und Abbau im landwirtschaftlichen Milieu, Studium der Beziehungen zwischen der chemischen Struktur der Verbindungen und ihrem Verhalten im Boden. Untersuchungsbericht der EidgenSssischen Forschungsanstalt fiir Agrikulturchemie und Umwelthygiene (FAC) Liebefeld (1993) R. Boos; F. WURST;K. SCHEIDL:Ermittelung der Bodenbelastung mit organischen Schadstoffen im Raume der Stadtgemeinde Steyregg. VDI-Berichte 837, 457 (1990) W. KAMVE: Schadstoffe im Boden insbesondere Schwermetalle und organische Schadstoffe aus langj~ihriger Anwendung yon SiedltmgsabffiUen. Landwirtschafdiche Untersuchungs- und Forschungsanstalt Speyer, Forschungsauftrag Nr. 10701003 Umweltbundesamt, Berlin 1987, 33 P. FROST;R. CAMENZtND;A. MAGERT;R. BONJOUR;G. KAP.LAGANIS: Organic micropollutants in Swiss sewage sludge. J. Chromatogr. 643, 379 (1993) A. ENGGIST;H. LIECHTI;F. BORER: Untersuchungen der Schadstoffbelastung von Boden und Vegetation entlang yon Kantonsstrassen sowie von Strassenwischgut. Amt fiir Umweltschutz, Kanton Solothurn, Bericht Nr. 6 (1994) J. PIETSCH;H. KAMIETH:Stadtb6den: Entwicklungen, Belastungen, Bewertung und Planung. Eberhard Blottner Verlag, Taunusstein 1991, 90 H. VOGEL; A. DESAULUS;H. HANI: Schwermetaltgehalte in den B6den der Schweiz. Schriftenreihe der Eidgen6ssischen Forschungs-
Substance Flow Analysis Method
[18] [19]
[20] [21]
[22]
[23] [24]
[25] [26]
anstalt Rir Agrikulturchemie und Umwelthygiene Liebefeld Nr. 40 (1989) E. KUHN; R. ARNET:Kompostqualit~it im Kanton Aargau. Bericht des Kantonalen Laboratoriums Aargau (1990) B. HURNI; D. WINISTORFER:Schwermetallbelastung von Gartenb6den, Kompost und Gemiiseproben im Raum Pratreln. Untersuchungsbericht des Amtes fiir Umweltschutz und Energie Kanton Basel-Landschaft (1989) KUS: Die Schwermetallbelastung von B6den in der Region Biel. Schlussbericht der Koordinationsstelle for Umweltschutz des Kanton Berns (1988) O. TABASARAN;W. B1DLINGMAIER;T. LEIBINGER;J. MOSKEN: Emissionen bei der Biomfillkompostierung. Schlussbericht des Instituts ffir Siedtungswasserbau, Wassergiite- und Abfaltwirtschaft der Universitiit Stuttgart (1990) W. MOCKE; H. C. STEINMETZER;J. STUMPP;W. BAUMEISTER;R. BONEBERG;O. VIERLE:PAK-lmmissionskonzenttationen - Ergebnisse mehrj~ihriger Messungen polycyclischer aromatischer Kohlenwasserstoffe in Bayern. UWSF-Z. Umweltchem. Okotox. 3,176 (1991) M. ZEHRINGER; C. HOHL; A. SCHNEIDER;M. R. SCHUPBACH: Untersuchungen zur Verteilung von Metallen in Schwebest~uben. Staub - Reinhalt.Luft 49, 439 (1989) S. K. GUPTA; H. HANI: Methodik zur Bestimmung biologisch relevanter Schwermetallkonzentrationen im Boden und Uberpriifung der Auswirkungen auf Testpflanzen sowie Mikroorganismen in belasteten Gebieten. Schlussbericht des COST-Projekts 681. Schriftenreihe der Eidgen6ssischen Forschungsanstalt fiir Agrikulturchemie und Umwelthygiene Liebefeld Nr. 2 (1989) C. HOHL; A. SCHNEIDER;M. ZEHR1NGER:Lufthygienische Untersuchungen im Raume Basel. Untersuchungsbericht des Kantonalen Laboratoriums Basel-Stadt (1987) K. SCHLAPFER;A. SCHNEIDER;M. SCH1)RCH;A. THOMAN:VOCund PAH-Immissionsmessungen in der Region Basel. Bericht im Auftrag des Lufthygieneamtes beider Basel (1992) Received: November 29, 1944 Accepted: April 11, 1995
Overview
Substance Flows Through the Economy and Environment of a Region Part h Systems Definition E s t e r v a n der V o e t , Ren~ Kleijn, L a u r a n van O e r s , Reinout Heijungs, R u b e n H u e l e , Paul M u l d e r
Part II: Modelling Ester v a n der V o e t , R e i n o u t H e i j u n g s , Paul M u l d e r , R u b e n H u e l e , Renh Kleijn, L a u r a n v a n O e r s Center of Environmental Science, Leiden University, P.O. Box 9518, NL-2300 RA Leiden, The Netherlands
Part I: Abstract
Part Ih Abstract
In the tradition of the study of materials flows through society, the Substance Flow Analysis (SFA) method is presented. SFA aims at providing the relevant information for a country's overall management strategy regarding single substances or coherent groups of substances. This article is dedicated to the presentation of a threestep general framework for SFA-type studies, and elaborates on its first step the systems definition. Attention is given to the definition of the external and internal system boundaries, the categorization of the system's elements, aspects of materials choice, time, and space, and how these depend on the aim of the conducted study. Moreover, a broader discussion is started on the need for standardization of materials flow studies in general.
In the tradition of the study of materials flows through society, the Substance Flow Analysis (SFA) method and its software tool SFINX are presented. SFA aims at providing the relevant information for a country's overall management strategy regarding single substances or coherent groups of substances. Three modelling techniques and their possibilities and limitations are discussed: Bookkeeping, static modelling, and dynamic modelling. The computer program SFINX can be used for varoius purposes: (1) to obtain an overview of stocks and flows of a substance in, out and through a nation's economy and environment for a specific year, (2) to trace the origins of specific pollution problems, and (3) to estimate the effectiveness of certain abatement measures. Each application has its own requirements with regard to data and modelling.
ESPR-Environ. Sci. & Pollut. Res. 2 (2) 89 (1995) 9 ecomed publishers, D-86899 Landsberg, Germany
89
Monitoring PAHs and Heavy Metals
Research Articles
Monitoring Polycyclic Aromatic Hydrocarbons (PAHs) and Heavy Metals in Urban Soil, Compost and Vegetation Markus Niederer, Annemarie Maschka-Selig, Christopher Hohl Kantonales Laboratorium Basel-Stadt, Postfach, CH-4012 Basel, Switzerland
Corresponding author: Dr. Markus Niederer
Abstract Samples of urban surface soil, composts, leaves from avenue limetrees and grass from park areas of the city of Basel (Switzerland) were analysed for polycyclic aromatic hydrocarbons (PAHs) and heavy metals. Generally, significant lower levels of PAHs (10 times lower) and heavy metals (3 - 70 times lower) were found in vegetation samples than in composts or soils. The concentrations of PAHs in soil and compost samples were in the same order of magnitude although 10 - 100-times higher in comparison to data given for rural soils in other studies, whereas heavy metal contents in urban soils and composts were 2 - 3 times higher than in rural samples. Using multivariate statistical analysis, it was possible to define similarities or special characteristics of single substances or substance groups in a given matrix reflecting their chemical properties and providing information on their specific emission sources.
1
Introduction
Polycyclic aromatic hydrocarbons (PAHs) and heavy metals are frequently found in various environmental samples as a result of anthropogenic contamination and/or natural processes [1]. In Switzerland, soil monitoring programmes concerning heavy metals have become routine and are based on federal legislation [2]. In contrast, comparatively little is known about environmental aspects and levels of PAHs in soil even though the combination of carcinogenic properties of certain congeners and their physico-chemical properties such as lipophilicity, stability and nonvolatility, as well as their ubiquitous distribution in the environment by various combustion sources, would define them as priority pollutants for soil monitoring programmes. Moreover, research concerning the influence of soil PAHs on growth of microorganisms [3] and senescence of plants [4] both show a negative impact. In this study, we report on current levels of PAH and heavy metal concentrations in urban samples (soil, compost, vegetation) from the city of Basel (200,000 inhabitants) and on the use of multivariate statistics (Factor Analysis) as a useful method to describe similarities or special characteristics of single substances or substance groups in the matrices. Furthermore, a comparison of theoretical pollutant levels of compost calculated by using data of concentrations found
ESPR-Environ. Sci. & Pollut. Res. 2 (2) 8 3 - 8 9 (1995) 9 ecomed publishers, D-86899 Landsberg, Germany
in grass and leaves with data of actual compost samples, as well as a comparison of the PAH profiles in different matrices, are included.
2
2.1
Experimental
Samples
Soil samples were taken from 21 sites at a depth of 0 - 20 cm as described in [5]. Compost samples came from 16 public district composting sites which mainly consist of kitchen refuse and garden litter. Leaf samples were taken from avenue lime-trees at 10 sites and grass samples from park areas or playgrounds for children (total 10 sites). Samples were stored at - 20 ~ until PAH-analysis or dried at 40 ~ and homogenised for heavy metal analysis [5].
2.2
Determination of PAHs
Frozen samples (vegetation: 10 g, soil and compost: 40 g fresh weight) were spiked with internal standards (deuterated pyrene-dl0, benzo[a]pyrene-d12, Cambridge Isotope Laboratories) for quality control of the sample preparation steps and calibration. Thereafter, samples were extracted with water-acetone-hexane (1:1 : 1, v/v / v) by shaking for 3 hours at room temperature. After prefiltering, the extract was separated in a separatory funnel and the organic phase cleaned up using silicagel column chromatography with cyclohexane as an eluent. The final eluate was concentrated by rotary evaporator to minimal volume and resuspended in toluene. Separation and identification of PAHs (-* Table 1) was performed by gas chromatography-mass spectrometry (Carlo Erba HRGC 5160, Fisons and ITD 700, Finnigan MAT) under the following conditions: DB-5MS (J&W) fused silica column (30 m x 0.25 mm I.D., 0.25/2m film) with a retention gap (0.5 m x 0.32 mm I.D., deactivated) used with on column injection of 0.5/21; temperature programme 90 ~ (lmin.)-(30 ~ ~ ~ ~ carrier gas (helium) 150 kPa; mass range 101 - 2 9 8 amu, full scan mode (sec./scan = 0.5).
83
Monitoring PAHs and Heavy Metals
Research Articles
Table 1: Identification of P A H separated by gas chromatography-mass spectrometry (GCMS) on the basis of retention times and mass Compound
Naphthalene Acenaphthylene Acenaphthene Fluorene Phenanthrene Anthracene Fluoranthene Pyrene Benzo[a]anthracene Chrysene a Benzo[b]fluoranthene a Benzo[k]fluoranthene Benzo[e]pyrene b Benzo[a]pyrene a Indeno[123-cd]pyrene a Dibenzo[ah]ant hracene a Benzo[ghi]perylene PAH (sum of 16)
Abbrev.
Nap Acnyl Acna Fluo Phen/an Phen/an Fluant Pyr Bzaan Chry Bzfl Bzfl Bep Bap Ind Dibzan Bzper ~ 16PAH
Retention
Mass
Mass for
itime (min)
(m/z)
GCMS Quantification
3.51 5.45 5.70 6.37 7.70 7.70 9.58 10.00 12.93 13.07 17.43 17.43 18.93 19.22 27.98 28.43 30.52 -
128 152 154 166 178 178 202 202 228 228 252 252 252 252 276 278 276 -
1 2 6 - 130 1 5 0 - 153 1 5 4 - 156 163 - 167 176 - 179 176-179 200 - 204 200 - 204 225 - 230 225 - 230 250 - 253 250 - 253 250 - 253 276 278 274 - 278 -
carcinogenic in animal experiments b not quantified, used for quality control a
For quantitation, 16 PAHs (Supelco, US EPA SW-846) were used for calibration in amounts ranging from 0.04 to 100 ng (correlation coefficients r > 0.995). Corrections were based on the internal pyrene-dl0 standard. Recovery rates of pyrene-dl0 and benzo[a]pyrene-d12 were about 90 % and 85 %, respectively. Reproducibility of three soil sample replicates expressed as mean relative standard deviation of PAHs was 1 1 % and the calculated limits of detection were approx. 3/~g/kg dwt. 2.3
Determination of heavy metals
Sample aliquots (approx. 0.5 g dry weight) of compost, leaves and grass were digested with a microwave system (MLS 1200, Milestone) using 65 % (w/w) nitric acid, 30 % (w/w) hydrogen peroxide and water. In the case of soil, extraction of 10 g dwt with 2 M nitric acid at 95 ~ was carried out according to the Swiss standard procedure [5]. Analysis of lead (Pb) in plants, nickel (Ni) and cadmium (Cd) was performed by Graphite Furnace-AAS (atomic absorption spectrometry, Zeemann 3030 Perkin-Elmer), Pb in soil and compost, copper (Cu) and zinc (Zn) by Flame-AAS (Perkin-Elmer 2380), and mercury (Hg) by Hg-cold vapour techniques (MHS-20, Perkin-Elmer). Reproducibility of compost replicates (n = 10) was 20 % for Pb, Cd and Cu, and 13 % for Hg. Zn and Ni were not tested. Limits of detection (mg/kg dwt) in plants, in soil and compost were 0.2 and 6.5 (Pb), 0.05 (Cd), 0.04 (Hg), 9.0 and 2.6 (Cu), 18 and 6.8 (Zn), 4.2 (Ni), respectively.
2.4
Multivariate statistical analysis
The Factor Analysis (STATISTICA for windows, StatSoft, Inc., Tulsa OK) procedure extracts principal components of 84
variables of interest and was used in our study to define groups of high correlated substances in soil and compost by linear combination [6]. In the case of grass and leaves pollutant levels, were too low and the analytical error too high to apply Factor Analysis.
3 3.1
Results and Discussion Comparison of pollutant levels in grass, leaves, composts and soils
Generally, on the base of dry weight (dwt) significant lower levels of PAHs (10 times lower) and heavy metals ( 3 - 7 0 times lower) were found in vegetation samples than in compost or soil ( ~ Fig. 1). For vegetation samples and soil, these differences can be mainly explained by the factor exposure time. Leaves and grass most likely reflect pollutant levels caused by airborne immission during part of the vegetation period between shooting and sampling (weeks to months). Soils, on the other hand, accumulate PAHs and heavy metals over decades.Their pollutant levels can therefore be strongly influenced by former immission situations no longer corresponding to current air pollution levels. In addition, we have to take into consideration that local factors other than airborne immission, e.g. use of fertilizers, can lead to soil contamination. In the case of compost, one would expect pollutant levels which are determined by levels of the major constituents being kitchen refuse (e.g. spoiled fruit, vegetable, coffee grounds) and garden litter (e.g. grass and leaves). Of these two categories, kitchen refuse can certainly be excluded as a major source of heavy metals and PAHs in compost, because of well etablished food quality controls. On the other hand, leaves and grass car~ accumulate large amounts of airborne pollutants due to their high specific surface (surface to weight ratio). For calculating theoretical pollutant levels in compost, we therefore assumed that our final compost originated exclusively from grass and leaves and that 1 kg of fresh vegetation material produces 0.6 kg of compost [7]. Theoretical concentrations obtained ranged between 9 % (Pb), 45 % (PAHs), 48 % (Cd), 63 % (Zn), 68 % (Cu) to a maximum 7 1 % (Hg) of the actual mean levels and hence explain only a fraction of the concentrations found. 3.2
Comparison of PAH and heavy metal concentrations
in soil Care has to be taken when comparing soil data from different studies. Differences e.g. in sampling depths and analytical procedures bias the pollutant concentrations obtained. In the case of PAHs, where the number of analysed congeneres vary, total amounts refered to in other studies are therefore based on our rough estimation for 16 PAHs if necessary. The mean total concentration of PAHs found in our soil samples are about two and four times higher than amounts found in other urban soils ( ~ Table 2). PAH levels of some of our sampling sites were even in the same range as those mentioned for soils near highways and, therefore, an inhibition effect on plant growth by plant hormones like PAHs cannot be excluded [4]. Much lower mean levels (10 to 100 times lower) are reported from rural and forest sites and, surprisingly, from sewage sludge ( ~ Table 2).
ESPR-Environ. Sci. & Pollut. Res. 2 (2) 1995
Research Articles
Monitoring PAHs and Heavy Metals
6O 50
400
160r-
I J
A
Box Plot of Lead
Box Plotof Copper
Box Plot of PAH (sum of 16) 140
+
350 C
120
o
300
i
~
40
E
+
E 20
100 8O
-F
I
4o
10
2~
I
60
100
2O leaves
grass
leaves
grass
compost
soil
0
~ leaves
Box Plot of Cadmium
Box Plot of Mercury
D
I.
L
80O
I O O
i
+
'
Fi
grass
compost
soil
Box Plot of Zinc
F
I
I
i 0.
"
50
soil
compost
200
E 150
600 o
O
E 0.
E, f
o----
"
400
E
200
=%
§ I
I
grass
leaves
compost
soil
leaves
grass
compost
soil
leaves
grass
compost
soil
Fig. 1"Box and whisker-plot of PAH and heavy metal concentrations in leaf samples of lime trees (n = 10), grass samples (n = ]tO), compost samples (n= 16) and soil samples (n= 21). Median ( t ) , 2 5 - 75 % percentile (~]) minimum-maximum value (I), outlier (o), extreme ( + )
Table 2: Comparison of soil PAH concentrations (mg/kg dwt) with other studies Study site (soils)
Urban (Basel,
n Number sample of PAH
21
16
Soil depth
0 - 20cm
PAH mean values 11.1_+11.9
CH) Urban (Bern,
Origin
Own
results 19
16
0 - 20cm
4.8_+4.5
[8]
4
8
0 - 3cm
[9]
3
10
0 - 20cm
11 12
16 27
0 - 20cm 0 - 10cm
4 27
4 6
0 - 20cm
1.3_+0.8 (2.6) a 0.2+0.0 (0.3) a 0.1 ___0.1 0.7_+0.5 (0.4) a 0.1 (0.4) a 0.4+0.4 (1.1) a
CH) Urban (Japan) Forest (Aargau, CH) Rural (CH) Rural (A) Rural (D) Sewage sludge (CH) Near highways (CH)
8
16
0 - 20cm
a Estimation for ~ 16PAH
ESPR-Environ. Sci. & Pollut. Res. 2 (2) 1995
21.0_+
[lO] [11] [12] [13] [14] [15]
Less caution has to be taken in comparing mean heavy metal concentrations from different studies in Switzerland due to standard analytical procedures [5]. Urban soils from Basel and Bern show similar mean (median) levels for all heavy metals (-* Table 3). The tendency of higher concentrations in Basel can be easily explained by the bigger size of the city. Differences between Swiss urban and rural sites are pronounced in the case of lead and zinc, but much less so for cadmium and copper. Data for German urban soils seems to represent much higher levels in general. However, due to unknown sampling depths and analytical procedures, an artefact cannot be ruled out. In both Table 2 and 3, the influence of highways on PAH and heavy metal (especially Pb) levels can be seen.
3.3
Comparison of PAH and heavy metal concentrations of compost
The heavy metal contents of 16 composting sites were determined on a half yearly basis over a period of 1.5 years (Aug. 90 - Feb. 92). The 4 consecutive values of the majority of sample sites showed relative standard deviations below 25 %. This is probably in the range of total analytical error and therefore a seasonal dependency cannot be seen. Due to high correlations with mercury ([12] and Fig. 4), the same has been suggested for PAHs which were only analysed in February 1992.
85
Monitoring PAHs and Heavy Metals
Research Articles
Table 3: Comparison of soil heavy metal concentrations (mg/kg dwt) with other studies. Median values of 0 - 20 cm soil depth and range of minima and maxima Study site CSoils) Urban (Basel, CH) Urban (Bern, 3H) Urban (D) b Rural (CH) rqear highways CH)
n sample
Pb
Cd
Cu
21
114 (23 - 366) 75 (27 - 350) 300 - 700 24 (14-41) a 94 (40 - 754)
0.37 (0.17-0.88) 0.32 (0.12-1.51) 0.9-2.1 0.23 (0.11 - 0.45)a 0.69 (0.28 - 2.47)
35 (18-121) 3O (8 - 2O0) 1-97 23 (9-61) a
73 77
237 18
Hg
Zn
Origin
0.3
143 (57 - 493) 109 (33-970) 140 - 600 56 (33 - 94) a 192 (78 - 906)
Own results
(0,1 - 1.0)
0.2 (0.1 - 20.0) 0 . 4 - 1.1
[8] [18] [17] [15]
a range including 80 % of values b amount of samples, median values and sampling depth are not known
In order to investigate possible regional differences within our study perimeter, we grouped data from composting sites of central and northern Basel (region A), which show high traffic and industrial density, and those from typical residential districts (region B). Mean pollutant levels in composting sites from region A where significantly higher for lead, cadmium, mercury and zinc (-* Fig. 2). Total PAH and Benzo[a]pyren~ mean levels are also higher in region A, but due to the enormous variance of levels of individual sites, the differences found were not statistically significant. The distribution of copper seems to be more or less homogeneous over all sites. In the case of nickel, the standard deviation for region B is too high for interpreting possible differences of mean values.
sites (-0 Table 4). In Basel we found similar PAHs values as in compost consisting of vegetation material originating from highway borders. More data is available in the case of cadmium, lead and zinc concentrations (-+ Table 5). The values found in composting sites of Basel are of the same order of magnitude as those reported from other urban regions. Comparing rural and urban compost, higher amounts of heavy metals can be found in urban sites, especially in the case of lead ( 2 - 4 times higher). Table 4: Comparison of compost PAH concentrations (mg/kg dwt) with other studies Study site Icomposts) Urban (Basel, ~H) Urban (Olten, ~H) Rural (CH) ,,Normal" Aargau, CH) Near highway IAargau, CH)
n sample
Origin
Number ]~PAH of PAH mean values
Own results [11]
16
16
5.5 ( 2 - 2 1 ) a
2
16
2.6
1 5
16 10
0.8 1.8 (3) b
[111 [18]
2
10
4.4 (7)b
[181
Min-Max b Estimation for Y.16PAH
=
Fig. 2: Differences of compost pollutants between city and industrial districts (region A: 8 composting sites) and residential districts (region B: 8 sites). Amount of PAH-samples: 1 per compost site ( = 8 per region), amount of anorganic samples: 4 per compost sites ( = 28 - 30 per region). Overall mean values in mg/kg dwt (= 100 %): 0.66 (Bap), 5.47 (]~ 16 PAH), 116.61 (Pb), 0.65 (Cd), 56.85 (Cu), 0.26 (Hg), 17.88 (Ni), 273.78 (Zn). * Significant (t-test, p>-
>>,
"1"
"T" -0.03
0 0
0.2
0.4
0.6
0.8
'1
-0.0"1
0,19
P A H s ( F a c t o r 1)
0.39
0,59
0.79
0.99
P A H s ( F a c t o r 1)
Fig. 4: Clusters (1 -3)and correlations (r) of analysed substances in soil (A) and compost (B)
Copper (3) is the only element which shows no correlation to other pollutants, neither in soil nor in compost. This special behaviour of copper can be explained by different copper specific input procedures: Abrasion of power lines of tramways or trains, and the use of copper containing plant sprays. Furthermore, the distribution of copper in airborne dust could also play a role because, in contrast to zinc, cadmium and lead, copper can sometimes dominate in coarse-grained dust fractions [23].
4
Conclusion
Compared to rural ("natural") conditions, elevated pollutant concentrations in soil and compost were predominantly found in the case of PAHs and lead. Both show a high affinity to soil particles under normal soil conditions and therefore are not readily bioavailable. Ingested amounts via the food chain, soil-plant or soil-plant-animal are too small to be of toxicological relevance for man. Hence, production restrictions on soil grown food, grazing bans and prohibition of using compost as a fertilizer are inadequate countermeasures in dealing with elevated, but not astronomically high, lead and PAIl concentrations in soil. In the case of compost, the ecological benefit of recycling kitchen refuse and garden litter outweighs the disadvantage of an additional soil pollution by this pathway, especially if decreasing future pollutant levels are taken into account due to enforcement of environmental laws. However, contamination levels in soils caused by decades of uncontrolled emissions are in an order of magnitude where destabilizing effects on the ecosystem, e.g. by disturbing plant growth due to hormonlike PAHs [4] or by upsetting microorganism populations vital for soil fertility [24], have to be taken into consideration and further monitoring is therefore indicated.
88
Analysing compost and vegetation can be seen as complementary to air and soil monitoring, representing intermediate phases between emission and immission. Our results for compost show differences between industrial regions with high density traffic and residential districts and are consistent with studies concerning the air pollution of Basel [25, 26]. Our calculation of theoretical pollutant concentrations in compost based on data for vegetation do not explain the analysed levels. The origin of levels in compost is hence not fully understand. Multivariate statistics is a useful method to extract similarities or special characteristics of pollutants in the respective matrix. Instead of obscure correlation tables, we can display simple graphics with groups of highly correlated substances, making interpretation of environmental data much easier. Acknowledgements We thank Theresa OTZ, Rita BOLLHALDER,Markus KALBERERand Nicole ACHERMANNfor their technical support in analysing heavy metals9
5
References
[1] F. SCHEFFER;P. SCHACHTSCHNABEL:Lehrbuch der Bodenkunde. 9 Ferdinand Enke Verlag, Stuttgart 1984, 271 [2] VSBo-Richtlinie: Verordnung fiber Schadstoffe im Boden. Anhang Art. 5 (1986) [3] N. T. EDWARDS:Polycyclichydrocarbons (PAH's)in the terrestrial environment - a review. J. Environ. Qual. 12:427 (1983) [4] M. BERTEIGNE;C. ROSE;J. GEP,ARD;P. DIZENGREMEL:Effects of polyaromatic hydrocarbons on the forest ecosystem and woody plants. Ann. Sci. For. 46, 561 (1989) [5] FAC: Methoden ffir Bodenuntersuchungen. Schriftenreihe der Eidgen6ssischen Forschungsanstalt ffir Agrikulturchemie und Umwelthygiene Liebefeld Nr. 5 (1989) [6] E. WEBER: Grundriss der bio]ogischen Statistik. VEB Gustav Fischer Verlag, Jena 1986, 464
ESPR-Environ. Sci. & Pollut. Res. 2 (2) 1995
Research Articles [7] [8] [9] [10]
[11]
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[16] [17]
K. FRICKE; T. TURK; H. VOGTMANN: Grundlagen der Kompostierung. EF-Verlag fiir Energie- und Umwelttechnik GmbH, Berlin 1990, 37 GSA: Stoffbelastung in der Agglomeration Ausserholligen St6ckacker/Bern. Untersuchungsbericht des Amtes ffir Gew~isserschutz und Abfaltwirtschaft des Kantons Bern (1994) T. SPITZER;S. KUWATSUKA:Residue levels of polynuclear aromatic compounds in urban surface soil from Japan. J. Chromatogr. 643, 305 (1993) A. KANZIG;M. WERFELI:Untersuchung von Waldb6den im Kanton Aargau auf die Belastung mit organischen Schadstoffen. Schlussbericht des Kantonalen Laboratoriums Aargau (1990) J. D. BERSET: Organische Fremdstoffe in der Landwirtscbaft: Verteilung und Abbau im landwirtschaftlichen Milieu, Studium der Beziehungen zwischen der chemischen Struktur der Verbindungen und ihrem Verhalten im Boden. Untersuchungsbericht der EidgenSssischen Forschungsanstalt fiir Agrikulturchemie und Umwelthygiene (FAC) Liebefeld (1993) R. Boos; F. WURST;K. SCHEIDL:Ermittelung der Bodenbelastung mit organischen Schadstoffen im Raume der Stadtgemeinde Steyregg. VDI-Berichte 837, 457 (1990) W. KAMVE: Schadstoffe im Boden insbesondere Schwermetalle und organische Schadstoffe aus langj~ihriger Anwendung yon SiedltmgsabffiUen. Landwirtschafdiche Untersuchungs- und Forschungsanstalt Speyer, Forschungsauftrag Nr. 10701003 Umweltbundesamt, Berlin 1987, 33 P. FROST;R. CAMENZtND;A. MAGERT;R. BONJOUR;G. KAP.LAGANIS: Organic micropollutants in Swiss sewage sludge. J. Chromatogr. 643, 379 (1993) A. ENGGIST;H. LIECHTI;F. BORER: Untersuchungen der Schadstoffbelastung von Boden und Vegetation entlang yon Kantonsstrassen sowie von Strassenwischgut. Amt fiir Umweltschutz, Kanton Solothurn, Bericht Nr. 6 (1994) J. PIETSCH;H. KAMIETH:Stadtb6den: Entwicklungen, Belastungen, Bewertung und Planung. Eberhard Blottner Verlag, Taunusstein 1991, 90 H. VOGEL; A. DESAULUS;H. HANI: Schwermetaltgehalte in den B6den der Schweiz. Schriftenreihe der Eidgen6ssischen Forschungs-
Substance Flow Analysis Method
[18] [19]
[20] [21]
[22]
[23] [24]
[25] [26]
anstalt Rir Agrikulturchemie und Umwelthygiene Liebefeld Nr. 40 (1989) E. KUHN; R. ARNET:Kompostqualit~it im Kanton Aargau. Bericht des Kantonalen Laboratoriums Aargau (1990) B. HURNI; D. WINISTORFER:Schwermetallbelastung von Gartenb6den, Kompost und Gemiiseproben im Raum Pratreln. Untersuchungsbericht des Amtes fiir Umweltschutz und Energie Kanton Basel-Landschaft (1989) KUS: Die Schwermetallbelastung von B6den in der Region Biel. Schlussbericht der Koordinationsstelle for Umweltschutz des Kanton Berns (1988) O. TABASARAN;W. B1DLINGMAIER;T. LEIBINGER;J. MOSKEN: Emissionen bei der Biomfillkompostierung. Schlussbericht des Instituts ffir Siedtungswasserbau, Wassergiite- und Abfaltwirtschaft der Universitiit Stuttgart (1990) W. MOCKE; H. C. STEINMETZER;J. STUMPP;W. BAUMEISTER;R. BONEBERG;O. VIERLE:PAK-lmmissionskonzenttationen - Ergebnisse mehrj~ihriger Messungen polycyclischer aromatischer Kohlenwasserstoffe in Bayern. UWSF-Z. Umweltchem. Okotox. 3,176 (1991) M. ZEHRINGER; C. HOHL; A. SCHNEIDER;M. R. SCHUPBACH: Untersuchungen zur Verteilung von Metallen in Schwebest~uben. Staub - Reinhalt.Luft 49, 439 (1989) S. K. GUPTA; H. HANI: Methodik zur Bestimmung biologisch relevanter Schwermetallkonzentrationen im Boden und Uberpriifung der Auswirkungen auf Testpflanzen sowie Mikroorganismen in belasteten Gebieten. Schlussbericht des COST-Projekts 681. Schriftenreihe der Eidgen6ssischen Forschungsanstalt fiir Agrikulturchemie und Umwelthygiene Liebefeld Nr. 2 (1989) C. HOHL; A. SCHNEIDER;M. ZEHR1NGER:Lufthygienische Untersuchungen im Raume Basel. Untersuchungsbericht des Kantonalen Laboratoriums Basel-Stadt (1987) K. SCHLAPFER;A. SCHNEIDER;M. SCH1)RCH;A. THOMAN:VOCund PAH-Immissionsmessungen in der Region Basel. Bericht im Auftrag des Lufthygieneamtes beider Basel (1992) Received: November 29, 1944 Accepted: April 11, 1995
Overview
Substance Flows Through the Economy and Environment of a Region Part h Systems Definition E s t e r v a n der V o e t , Ren~ Kleijn, L a u r a n van O e r s , Reinout Heijungs, R u b e n H u e l e , Paul M u l d e r
Part II: Modelling Ester v a n der V o e t , R e i n o u t H e i j u n g s , Paul M u l d e r , R u b e n H u e l e , Renh Kleijn, L a u r a n v a n O e r s Center of Environmental Science, Leiden University, P.O. Box 9518, NL-2300 RA Leiden, The Netherlands
Part I: Abstract
Part Ih Abstract
In the tradition of the study of materials flows through society, the Substance Flow Analysis (SFA) method is presented. SFA aims at providing the relevant information for a country's overall management strategy regarding single substances or coherent groups of substances. This article is dedicated to the presentation of a threestep general framework for SFA-type studies, and elaborates on its first step the systems definition. Attention is given to the definition of the external and internal system boundaries, the categorization of the system's elements, aspects of materials choice, time, and space, and how these depend on the aim of the conducted study. Moreover, a broader discussion is started on the need for standardization of materials flow studies in general.
In the tradition of the study of materials flows through society, the Substance Flow Analysis (SFA) method and its software tool SFINX are presented. SFA aims at providing the relevant information for a country's overall management strategy regarding single substances or coherent groups of substances. Three modelling techniques and their possibilities and limitations are discussed: Bookkeeping, static modelling, and dynamic modelling. The computer program SFINX can be used for varoius purposes: (1) to obtain an overview of stocks and flows of a substance in, out and through a nation's economy and environment for a specific year, (2) to trace the origins of specific pollution problems, and (3) to estimate the effectiveness of certain abatement measures. Each application has its own requirements with regard to data and modelling.
ESPR-Environ. Sci. & Pollut. Res. 2 (2) 89 (1995) 9 ecomed publishers, D-86899 Landsberg, Germany
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