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Record of industrial pollution in polish ombrotrophic peat bogs
Phys. Chem. Earth (A), Vol. 26, No. 1l-12, pp. 859-866, 2001 0 2001 Published by Elsevier Science Ltd
Pergamon
All rights reserved 1464-1895/01/$ - see front matter
PII: S1464-1895(01)00133-S
Record of Industrial Pollution in Polish Ombrotrophic Peat Bogs Z. Strzyszcz and T. Magiera Institute
of Environmental Engineering, Polish Academy of Sciences, ul. M. Sklodowskiej-Curie 34, 4 l-8 19 Zabrze, Poland
pollution including ferrimagnetic minerals (Strzyszcz 1989, Heller et al. 1998). On some areas under strong industrial anthropopressure with the relatively high industrial dustfall, the high correlation coefficients (0.9) between magnetic susceptibility and the content of some heavy metal was noticed (Strzyszcz and Magiera 1998). The sources of pollution are the same for magnetic particles and heavy metals (mostly coal burning). The high correlation was often observed for sulphophile metals (Zn, Pb, Cd) occuring in coal (Strzyszcz et al. 19%). The relatively high correlation may be expected also for selenium, which quite often substitutes sulphur in sulphides. The Se/S ratio is between 0.1 - 0.0001 in sulphides of different origin (Reimann and Caritat, 1998). The observed correlation coefficients were higher in areas with higher industrial dustfall. This is of special importance in case of lead. In some areas close to industrial centres the Pb concentration in forest litter exceeds 2 to 15 times national and international standards (Strzyszcz and Magiera, 2000). Considering the fact that 27% of the Polish territory is covered by forest, where the acid soil predominates, this could be an “ecological time bomb”. The open areas are mostly under agricultural cultivation, where systematic ploughing causes “dilution” of anthropogenic magnetic particles in the arable layer (about 20 cm). This fact leads to an interpretation problem for magnetic monitoring of industrial pollution. In case of soil pollution studies in open areas only the profiles with undisturbed deposition may be useful for the ecological interpretation of the magnetic signal. Ombrotrophic (highland) peats and bogs are suitable collectors of dust pollution. They are built up above the groundwater table and therefore all non-atmospheric pollution input may be excluded. Therefore the deposited dust including the ferri(o)magnetic particles can be preserved “in situ” for a long time. Additionally, very low, even negative magnetic susceptibility of organic matter is
Abstract. Peat contains mostly diamagnetic organic matter, which is a good collector of all kinds of atmospheric dusts and industrial pollution. Ombrotrophic peat bogs are built up above the ground water table, so deposition and accumulation of magnetic particles are not influenced by ground water and the deposited particles remain largely “in situ“. During this study, 6 Polish ombrotrophic peat bogs from different locations have been investigated. Peat cores of about 30-50 cm in depth were taken from every bog. The specific low-frequency magnetic susceptibility was measured along the peat profile in fresh, not dried sample. In most profiles the susceptiiility below 10 cm was slightly negative, which is characteristic for clean organic material. Above a depth 8-10 cm the susceptibility starts to increase. Independently of the profile location, the increase is observed in all bogs and according to isotopic (C-14) dating it is connected with the post war industrialisation (1945-1955). The maximum of the magnetic deposition noticed as maximum susceptibility enhancement is observed in a depth of about 5 cm below the surface. In the south-western part of Poland the peat profiles show the maximum susceptibility above 350 x10‘m3kg-‘ . The susceptibility decreases in profiles from the central part of Poland to 30-60. In the northern and southeastern part of the country the maximum observed susceptibility is about 10 x10‘8m?cg-1. Hysteresis parameters pointed at anthropogenic ferromagnetic minerals as a carrier of magnetic signal. 0 2001 Published by Elsevier Science Ltd. All rights reserved
1. Illmdwh A detailed forest soil study carried out from 1988 showed that forest stand is able to accumulate anthropogenic Correspondence to: Tadeusz Magiera
859
860
Z. Strzyszcz and T. Magiera
: Record of Industrial Pollution in Polish Ombrotrophic
helpful for identifying even small concentrations of particulate magnetic pollutants, resulting from increased industrial dust deposition. Former data point at the existence of a high positive correlation between magnetic susceptibility and heavy metal content also in ombrotrophic peats (Oldfield et al., 1981, Tolonen and Oldfield 1986). By analysing the distribution of magnetic susceptibility and heavy metal content in a vertical peat profile it is possible to reconstruct the annual deposition of anthropogenic dust over the study area in the past. In Poland, the area covered by peat bogs is 17 060 km2 but only about 1000 km* are ombrotrophic peats. They are located in areas influenced by anthropogenic pollution of different degree and of digerent amount of annual dustfall. The main purpose of this work was to study spatial and vertical distribution of magnetic susceptibility in different peat bogs as a result of industrial pollution influx. 2. Material and methods Six peat bogs from different localities in Poland were selected for this study (Fig. 1). The first two (Izera and Wegliniec Bog) are located in south-western Poland in an area called “Black Triangle” (area crossing the Polish, Czech and German borders). This area is strongly influenced by pollution from many power plants located in Northern Bohemia, Saxony and the large Polish Turow power plant. The Myszkow Bog is located 40 km NE from the Upper Silesian Industrial Region. Kampinos Bog is located in Kampinos National Park, about 30 km W from Warsaw. Wolosate profile is located in the south-eastern part of Poland in a relatively clean area of Bieszczady Mountains (Bieszczady National Park). Leba profile is located in the coastal area in Northern Poland on the territory of Slowinski National Park, which is one with the cleanest areas of Poland.
--______------.
Fimre 1. Lmations of the studied ueat hoes.
Peat Bogs
During the field study, surface magnetic susceptibility measurements were performed using MS2D Bartington loop sensor as a prescreening to find places with the possibly highest degree of pollution within the studied peat bog. From every bog 1 or 2 shallow profiles (30-50 cm depending on the location) were collected. For the laboratory measurement susceptibility samples were taken (if possible) from every 1 cm and measured using MSZB Bartington sensor. Some characteristic samples, exhibiting a sudden increase or decrease in susceptibility or local maxima, were dated using the C-14 methodology in Radiocarbon Laboratory of Silesian Technical University in Gliwice, Poland (Jungner et al., 1995) Magneto mineralogical data were obtained from strongest magnetic samples from Izera and Wegliniec Bogs. The following parameters were measured in the Magnetic Laboratory of CEREGE, Aix-Marseille University, France: coercivity (Hc), coercivity of remanence (I%&, saturation magnetisation (MS) and saturation remanence (Mr). The contents of heavy metal, extractable in 2M HN03 (mobile fraction) was determined in samples from every 1 cm layer of each profile according to Swiss methodology (Commentary on...,1987). The samples were determined on Perkin Elmer Atomic Absorption Spectroscope. The selenium content extractable in aqua regia was determined in 15 samples with increased susceptibility or heavy metal contents. Sample mineralization was done under pressure in closed MDS2000 microwave system. The Se content was determined using AAS methodology (Varian SpectrAA 300 equipped with VGA - 76 section). 3. Results The highest v&es of magnetic susceptibility were measured in the Wegliniec and Izera Bog (Fig. 2a,c). In the Weglinic peat profile the maximum measured value was 39 1 xlO”m%g-’ in the layer 3-4 cm below surface. Two sudden increases in magnetic susceptibility were noticed in the Wegliniec profile. The first one at a depth of 9 cm (dated for the period 1945 - 1955) and the second one at 5 cm (dated for the period 1970 - 1980). A very similar distribution of magnetic susceptibility was observed in the Izera Bog profile (Fig 2~). The maximum susceptibility was observed at 4 cm (180 xlo”m3kg-‘) and the highest increase was observed at 8 cm and 4 cm below surface. Both are related to the same time period as in Wegliniec. The magnetic material present in studied peats exhibits a thin, “wasp-waisted” hysteresis loop which is almost saturated in 300 mT (Fig. 3). Such shape of hysteresis loop is often observed in fly ashes produced by coal burning (Petrovsky et al. 1998). Most of the magnetic fraction in coal-fired fly ash is present in the relatively large grain-size fraction 2 to 50 pm (Strzyszcz et. al. 1996). The shape of hysteresies loop as well as the fresuency dependence of
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Figure 2n. Magnetic susceptibility xlO‘sm%g~‘(black solid line), Mn (pale dotted line), Zn (dark dotted line) and F% (grey solid line) in Wegliniec peat profile. Heavy metal COtWtillppttl
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Figure 2b. Magnetic susceptibility xlO~‘m%g~‘(black solid line), Cd (pale dotted line), Cu (dark dotted line), Ni (lined line) and Cr (grey solid line) in Wegliniec profile. .Heavy metalcontentinppm
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Figure 2c. Magnetic susceptibility x109m3kg’ (black .&id line), Mn @ale dotted line), Zn (dark dotted line) and Pb (grey solid line) in Izera Bog profile. Heavy metal content in PPm
Figure 2d. Magnetic susceptibility xlO‘xl%g-’ (black solid line), Cd (pale dotted line), Cu (dark dotted line), Ni (lined line) and Cr (grey solid line) in Izera Hog profile. Heavy metalcontentinppm
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: Record of Industrial Pollution in Polish Ombrotrophic
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Figure 2f. Magnetic susceptibility x104m%$ (black solid line), Cd (pale dotted line), Cu (dark dotted line), Ni (lined line) and Cr (grey solid line) in Myszkow peat profile. Heavy metal content in ppm
Figure 2e. Magnetic swceptibilii xlo’8m?cge’ (black solid line), Mn (pale dotted line), Zn (dark dotted line) and Pb (grey solid line) in Myszkow peat profile. Heavy metal contentinppm
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Figure 2g. Magnetic susceptibility x10-9m3kg-’ (black solid line), Mn (pale dotted line), Zn (dark dotted line) and Pb (grey solid line) in Kampinos NP peat profile. Heavy metal COllhltillppm
Figure th. Magnetic susceptibility xlO*m3kg-’ (black solid line), Cd (pale dotted line), Cu (dark dotted line), Ni (Iii line) and Cr (grey solid line) in Kampmos NP peat profile. Heavy metal content in ppm
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2. Strzyszcz and T. Magiera : Record of Industrial Pollution in Polish Ombrotrophic Peat Bogs -40
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Figure 2i. Magnetic susceptibility xlO-gmw’ (black solid line), Mn (pale dotted line), Zn (dark dotted line) and Fb (,.s-elid line) in W&sate peat profile. Heavy metal content
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Figure 21. Magnetic susceptibility x10-‘m3kg-’ (black solid line.), Cd (pale dotted line), Cu (dark dotted line), Ni (Iii line) and Cr (prey solid line) in Wolosate peat profile. Heavy metalcontentinppm
J
Figure 2k Magnetic susceptibility x104m3kg* (black solid line), Mn (pale dotted line), Zn (dark dotted line) and Pb (grey solid line) in L&a peat profile. Heavy metal content in ppm
-10
Figure 21. Magnetic
susceptibility x104m3kg’ (black solid line), Cd (pale dotted line), Cu (dark dotted line), Ni (lined line) and Cr (grey solid line) in L&a peat profile. Heavy metaicontentinppm
6
Z. Strzyszcz and T. Magiera
864
: Record of Industrial Pollution in Polish Ombrotrophic
Peat Bogs
l,OOE-05
magnetic susceptibility which, with one exception is between 2.0 and 3.3 % (Tab. I), suggests that the susceptibility in studied peats is controlled by anthropogenic ferrimagnetic minerals derived from dust pollution (Magiera and Strzyszcz 2000, Magiera et al., 2000). Coercivity m) in the Izera peat is between 10.2 and 14.8 mT (average 11.5 mT) whereas in Wegliniec peat between 8.1 and 10.8 mT (average 9.7mT) (Tab. 1). It confirms the observations of Flanders (1994) that Hc decreases with distance from the source of fly ash emissions. In case of Izera Bog profile a similarity between susceptibility and lead distribution is observed, especially in the upper part (Fig 2~). Absence of such similarity between susceptibility and Zn suggests remote sources of pollution. Lead is present in higher amounts then zinc in industrial aerosols, which are transported on long distances. A considerably lower correlation between magnetic susceptibility and Pb content (0.41) in Wegliniec may suggest a more local character of pollution (Strzyszcz 1999). In both peat profiles, a relationship between magnetic susceptibility and Cu is also observed (Fig 2b,d). The maximum in Cu concentration in Wegliniec and Izera peat profiles is more or less at the same depth as that of the susceptibility value and both curves are remaining parallel. The maximum measured magnetic susceptibility in Myszkow and Kampinos profiles is about 60 x10am3kg-’ and the distribution in the profile is slightly different (Fig 2e,g). The first noticeable increase in susceptibility is at 12 cm in Myszkow and at 10 cm in Kampinos, but 2 local maxima were also observed. In Myszkow, the first maximum is observed between 9 and 6 cm and in Kampinos at 8-7 cm. The second maximum in Kampinos is at 5 whereas in Myszkow at 4 cm. The secondary maxima are observed in the same layer as in the Wegliniec and Izera Bog. They are dated to 197Os, the period of highest dust emission in Poland. The first maximum in Myszkow dates
I--/--
Wegliniec Bog
190 350 390 51 45
2.3 2.1 2.6 2.9 2.7
1
i
I
a -l,OOE-05
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i.............. .. ..
.
CT)
. .
. . . . . . . . . . . . . . . . .._..............
Figure 3. Hysteresis loop of smples f&m the strongest magneticly peat layers. a) Izera Bog, b) Wegliniec peat
between 1940-1950 and is probably connected to the postwar industrial&ion and intensive exploration and processing of Pb and Zn ores in Bytom and Olkusz areas, located about 30 km from the sampling site. The evidence for this is an extreme high content of heavy metals (especially Pb), which decreases in the upper layers, even in 4 cm depth, where the second susceptibility maximum, related to deposition of dust derived from intensive electricity production in 197Os, is observed (Fig. 2e) The second susceptibility maximum in Kampinos is also
Table 1. Magnetic chat-a&xi& of anthmpogenic particles present in peats from south-western Poland. Sample no Study area 7.fd (!z) (z-) ( lO-G3kg-l) % 11 117 4.0 10.3 26.3 I2 136 3.3 10.8 26.2 I3 32 2.1 14.8 26.8 Lzera Bog I4 175 2.0 10.6 26.3 I5 17 2.3 11.3 26.3 Wl w2 w3 w4 w5
l
8.1 9.2 10.5 10.8 10.0
23.1 23.3 25.2 25.7 25.0
MS (mAm’kg_‘) 40.1 114.4 36.8 110.4 41.8
Ml (mAm’kg~‘) 9.6 21.7 7.1 19.5 6.2
125.4 239.5 190.6 49.4 14.7
20.7 41.6 35.7 9.3 2.6
Z. Strzyszcz and T. Magiera
: Record of Industrial Pollution in Polish Ombrotrophic
combined with increase in Cy Cr, Cd and Pd content (Fig. 2g,h). Dating again suggests the period of 1940 - 1950 or 1950 - 1960 - the post-war industrialisation in Warsaw. Peat profiles from Wolosate Bog (Bieszczady Mts.) and Leba (Slowinski National Park) reveal a very low magnetic susceptibility (8 - 10 xlO”m%g“, however increased emission in 1970s is observed as a distinct increase in magnetic susceptibility at 5 cm below the surface (Fig. 2i,k). In the lower layers a stable, slightly negative susceptibility was observed. In spite of the very low susceptibility also an increase of Zn, Cu, Cd and Mn in case of Wolosate (Fig. 2ij) and Zn and Cu in case of Leba (Fig. 2k,l) was noticed. In the uppermost layers from Wolosate profile the Zn dominates over Pb. The Zn content decreases downwards the profile to a value of 4 mg/kg. The selenium content which was determined in 15 samples taken from peat layers with increased magnetic susceptibility or heavy metal content from each locality except Leba was between 0.094 mg/kg in the uppermost layer from Kampinos peat bog and 2.663 mgikg in the 3-4 cm from Wegliniec, which was the most magnetic sample recognised during this study (Tab. 2). The correlation coefficient between magnetic susceptibility and selenium content was 0.66.
865
Peat Bogs
Table 2. Selenium content in some peat layers. Depth below Suscgptibility Peat locality ( 10gm%g.‘) surface
-m Izera Bog Izera Bog Izera Bog Izera Bog Weliniec Bog Welinkc Bog Weliniec Bog Weliniec Bog Weliniec Bog Kampinowx NP Kampinows NP KampixwsNP Myszkbw WdOSh
63.0 62.6 69.8 32.1 -1.2 85.2 180.4 252.8 27.7 0.6 2.2 26.0 13.9 48.3 12.3
o-1 cm 3-4cm 6-7 cxn 8-9 cm 12-13 cm o-1 cm l-2cm 3-4czn 5-6cm 9-10 cm o-1 cm 4-5cm 7-8 cm 5-6cm 1-2 cm
Sew&d (mm) 0.98 0.855 0.192 0.631 0.426 0.143 0.614 2.563 0.854 0.647 0.094 0.271 0.727 0.239 0.853
Correlation coefficient 0.661
and Easter Saxony may influence this area. Strong predominance of Pb over Zn in Izera Bog suggests remote source of pollution. Decrease in Hc of magnetic material from Wegliniec as well as less distinct predominance of Pb over Zn suggest both long-distance and local effects, the local effect being here stronger because the peat bog is situated very close to the city of Wegliniec.
4. Disarssion 5. conclusions Magnetic susceptibility in ombrothrophic peats located in open areas is lower then in forest soils. This is a result of the accumulation ability of forest stands. The enhanced magnetic susceptibility in ombrothrophic peats seems to be the result of anthropogenic magnetic particle deposition only, because in the lower peat layers the susceptibility is very low or even negative, which is characteristic for “clean” diamagnetic organic matter. On the base of this assumption, the degree of dust pollution impact for open peat bogs and surrounding areas can be estimated as fallow: < 20 x10‘8m%gV’low moderate 20 - 50 x10”m3kg-’ > 50 x10*m3kg-’ high According to Thompson and Oldfield (1986) the maximum susceptibility for mostly sediments is 20 xlOam%g-‘, so the level below can be consider as a natural level for sedimentary material in peat bog. In each case with susceptibility exceeding 50 xlO‘*m%g“, the concentration of at least one pollutant is over an acceptable level (according the national standards). In case of Wegliniec, Izera and Myszkow, Pb exceeds 100 mg/kg, which is the acceptable level for soil in Poland. The higher degree of environmental hazard in southwestern part of Poland is probably caused by the large Turow Power Plant, which started its operation and emissions in early 195Os, period related (according to C-14 dating) to a first sudden increase of susceptibility in Izera and Wegliniec Bogs at 8-9 cm. Additionally, the longdistance pollution transport from North-Western Bohemia
1. Magnetic SusceptibiliQ in ombrothrophic peat bogs from open area is about 10 - 50 times lower then in surrounding forest soils. It results from the lower accumulation ability of peats as compared to forest stands. The tree canopy plays an important role in capturing the dust pollutants from the air and its accumulation in the topsoil. 2. The highest magnetic susceptibility, heavy metal and selenium contents were observed in peat bogs located in the south-western part of Poland close to the Czech and German border and they result from long-distance pollution even enhanced in some cases due to additional local sources. 3. In spite of sometimes very low magnetic susceptibility, a sudden increase of its value due to anthropogenic input can be easily recogniscd at depths of 5 - 8 cm depending on local conditions. This effect can be observed over the whole of Poland, even in relatively clean areas. This may be a general effect due to increased emissions in the second part of the 20” century. 4. Magnetic measuremens of ombrotrophic peat seem to be method suitable for obtaining records of spatial and temporal variations in the atmospheric fallout of particulates resulting from industrial (long-distance) and domestic (local) combustion pmsses. 5. Magnetic susceptibility in peat bogs seems to be a good method in estimating the degree of environmental hazard in open areas. In cases where the magnetic susceptibility
Z. Strzyszcz and T. Magiera
866
: Record of Industrial Pollution in Polish Omhrotrophic
exceeding 50 x10am3kg-‘, the hazard is significant and high concentration of at least one pollutant (including heavy metals) can be expected. Acknowledgements We thank the Committee of Scientific Researches in Poland, which supports this study in the frame of the project “Using of magnetic methods in monitoring of industrial dust immission in open areas based on ombrotrophic peat bog studies” (3 TO9C 036 15). We also thanks dr Francoise Leveque and Prof. Pierre Rochette who helped as during the measurement and interpretation of hysteresis parameters in CEREGE laboratory of University of Aix-Marseille, France in the frame of the POLONIUM scientific exchange program. References 1.
2.
3.
4.
5.
6.
7.
Commentary on the ordinance relating to pollutants in soil (VSBo; of June 9, 1986), Text to the Environmental Legislation, Bern, 1987. Flanders, P.J., Collection, measurements and analysis of airborne magnetic particulates from pollution in the environment. J. Appl. Phys., 75, 5931-5936. 1994. Heller, F., Strzyszcz, Z., Magiera,T., Magnetic record of industrial pollution in forest soils of Upper Silesia, Poland. J. Geophys. Res, 103, 17767-17774, 1998. Jungner, H., Sonmnen, E., Possnert, G., Tolonen, K., Use of Bomb-Produced 14C to Evaluate the Amount of CO2 Emanating from Two Peat Bogs in Finland Radiocarbon, Vol. 37, No 2, 1995. Magiera, T., Strzyszcz, Z., Ferrimagnetic minerals of anthropogenic origin in soils of some Polish national parks. Water Air and Soil pollution., 124, 37-48, 2000. Magiera, T., Strzyszcz, Z., Kapicka, A., Petrovsky, E., Ferrimagnetic minerals of anthropogenic origin in highland peats in south-western Poland and northern Bohemia. Geologica Carpatica. vol 51. no 2. s. 199200,2000. Oldfield, F., Tolonen, K., Thompson, R., History of particulate atmospheric pollution from magnetic measurements in dated Finnish peat profiles, Ambio 10, 185-8, 1981.
8.
Peat Bogs
Petrovsky, E., Kapicka, A., Zapletal, K., Sebestova, E., Spanila, T., Dekkers, M,J, Correlation between magnetic parameters and chemical composition of lake sediments from northern Bohemia - preleminary study. Phys. Chem. Earth, 23, 1123-l 126, 1998. 9. Reimann, C., de Caritat, P., Chemical elements in the environment, Springer-Verlag, Berlin, Heidelberg, 1998. 10. Strzyszcz, Z., Ferromagnetic properties of forest soils being under influence of industrial pollution. Air pollution and forest decline. In Proc. 14th Int. Meeting for Specialist in Air Pollution Effects on Forest Ecosystems. IUFRO, Interlaken, pp 201-207, 1989. 11. Strzyszcz, Z., Heavy metal contamination in motmtain soils of Poland as a result of anthropogenic pressure, Biology Bulletin, Vol26, no 6, 593-605, 1999. 12. Strzyszcz, Z., Magiera, T., Magnetic susceptibility of forest soils in Polish - German border area, Geologica Carpatica,vol. 49, no. 4 p. 241-242. 1998. 13. Strzyszcz, Z., Magiera, T., The main sources of chemical degradation of soil in urban areas, Proceedings of First International Conference on Soils of Urban, Industrial, Traflic and Mining Areas, University of Essen, Germany, pp. 695-699,2000. 14. Strzyszcz, Z, Magiera, T., Bzowski, Z., Magnetic susceptibility as indicator of soil contamination in some regions of Poland, Roczniki Gleboznawcze. SUPPL. T. XLIV. Warszawa s. 85-93, 1994. 15. Strzyszcz, Z., Magiera, T., Heller F., The influence of industrial immissions on the magnetic susceptibility of soils in Upper Silesia, Poland Studia geoph. et geod., 40,276 - 286. 1996. 16. Thompson R., Oldfield F., Environmental magnetism. Allen and Unwin, London, 1986. 17. Tolonen, K., Oldfield, F., The record of the magneticmineral and heavy metal deposition at Regent Street Bog, Fredicton, New Brunswick, Canada, Phys. Earth Planet Int. 42, 57-66, 1986.
Pergamon
All rights reserved 1464-1895/01/$ - see front matter
PII: S1464-1895(01)00133-S
Record of Industrial Pollution in Polish Ombrotrophic Peat Bogs Z. Strzyszcz and T. Magiera Institute
of Environmental Engineering, Polish Academy of Sciences, ul. M. Sklodowskiej-Curie 34, 4 l-8 19 Zabrze, Poland
pollution including ferrimagnetic minerals (Strzyszcz 1989, Heller et al. 1998). On some areas under strong industrial anthropopressure with the relatively high industrial dustfall, the high correlation coefficients (0.9) between magnetic susceptibility and the content of some heavy metal was noticed (Strzyszcz and Magiera 1998). The sources of pollution are the same for magnetic particles and heavy metals (mostly coal burning). The high correlation was often observed for sulphophile metals (Zn, Pb, Cd) occuring in coal (Strzyszcz et al. 19%). The relatively high correlation may be expected also for selenium, which quite often substitutes sulphur in sulphides. The Se/S ratio is between 0.1 - 0.0001 in sulphides of different origin (Reimann and Caritat, 1998). The observed correlation coefficients were higher in areas with higher industrial dustfall. This is of special importance in case of lead. In some areas close to industrial centres the Pb concentration in forest litter exceeds 2 to 15 times national and international standards (Strzyszcz and Magiera, 2000). Considering the fact that 27% of the Polish territory is covered by forest, where the acid soil predominates, this could be an “ecological time bomb”. The open areas are mostly under agricultural cultivation, where systematic ploughing causes “dilution” of anthropogenic magnetic particles in the arable layer (about 20 cm). This fact leads to an interpretation problem for magnetic monitoring of industrial pollution. In case of soil pollution studies in open areas only the profiles with undisturbed deposition may be useful for the ecological interpretation of the magnetic signal. Ombrotrophic (highland) peats and bogs are suitable collectors of dust pollution. They are built up above the groundwater table and therefore all non-atmospheric pollution input may be excluded. Therefore the deposited dust including the ferri(o)magnetic particles can be preserved “in situ” for a long time. Additionally, very low, even negative magnetic susceptibility of organic matter is
Abstract. Peat contains mostly diamagnetic organic matter, which is a good collector of all kinds of atmospheric dusts and industrial pollution. Ombrotrophic peat bogs are built up above the ground water table, so deposition and accumulation of magnetic particles are not influenced by ground water and the deposited particles remain largely “in situ“. During this study, 6 Polish ombrotrophic peat bogs from different locations have been investigated. Peat cores of about 30-50 cm in depth were taken from every bog. The specific low-frequency magnetic susceptibility was measured along the peat profile in fresh, not dried sample. In most profiles the susceptiiility below 10 cm was slightly negative, which is characteristic for clean organic material. Above a depth 8-10 cm the susceptibility starts to increase. Independently of the profile location, the increase is observed in all bogs and according to isotopic (C-14) dating it is connected with the post war industrialisation (1945-1955). The maximum of the magnetic deposition noticed as maximum susceptibility enhancement is observed in a depth of about 5 cm below the surface. In the south-western part of Poland the peat profiles show the maximum susceptibility above 350 x10‘m3kg-‘ . The susceptibility decreases in profiles from the central part of Poland to 30-60. In the northern and southeastern part of the country the maximum observed susceptibility is about 10 x10‘8m?cg-1. Hysteresis parameters pointed at anthropogenic ferromagnetic minerals as a carrier of magnetic signal. 0 2001 Published by Elsevier Science Ltd. All rights reserved
1. Illmdwh A detailed forest soil study carried out from 1988 showed that forest stand is able to accumulate anthropogenic Correspondence to: Tadeusz Magiera
859
860
Z. Strzyszcz and T. Magiera
: Record of Industrial Pollution in Polish Ombrotrophic
helpful for identifying even small concentrations of particulate magnetic pollutants, resulting from increased industrial dust deposition. Former data point at the existence of a high positive correlation between magnetic susceptibility and heavy metal content also in ombrotrophic peats (Oldfield et al., 1981, Tolonen and Oldfield 1986). By analysing the distribution of magnetic susceptibility and heavy metal content in a vertical peat profile it is possible to reconstruct the annual deposition of anthropogenic dust over the study area in the past. In Poland, the area covered by peat bogs is 17 060 km2 but only about 1000 km* are ombrotrophic peats. They are located in areas influenced by anthropogenic pollution of different degree and of digerent amount of annual dustfall. The main purpose of this work was to study spatial and vertical distribution of magnetic susceptibility in different peat bogs as a result of industrial pollution influx. 2. Material and methods Six peat bogs from different localities in Poland were selected for this study (Fig. 1). The first two (Izera and Wegliniec Bog) are located in south-western Poland in an area called “Black Triangle” (area crossing the Polish, Czech and German borders). This area is strongly influenced by pollution from many power plants located in Northern Bohemia, Saxony and the large Polish Turow power plant. The Myszkow Bog is located 40 km NE from the Upper Silesian Industrial Region. Kampinos Bog is located in Kampinos National Park, about 30 km W from Warsaw. Wolosate profile is located in the south-eastern part of Poland in a relatively clean area of Bieszczady Mountains (Bieszczady National Park). Leba profile is located in the coastal area in Northern Poland on the territory of Slowinski National Park, which is one with the cleanest areas of Poland.
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Fimre 1. Lmations of the studied ueat hoes.
Peat Bogs
During the field study, surface magnetic susceptibility measurements were performed using MS2D Bartington loop sensor as a prescreening to find places with the possibly highest degree of pollution within the studied peat bog. From every bog 1 or 2 shallow profiles (30-50 cm depending on the location) were collected. For the laboratory measurement susceptibility samples were taken (if possible) from every 1 cm and measured using MSZB Bartington sensor. Some characteristic samples, exhibiting a sudden increase or decrease in susceptibility or local maxima, were dated using the C-14 methodology in Radiocarbon Laboratory of Silesian Technical University in Gliwice, Poland (Jungner et al., 1995) Magneto mineralogical data were obtained from strongest magnetic samples from Izera and Wegliniec Bogs. The following parameters were measured in the Magnetic Laboratory of CEREGE, Aix-Marseille University, France: coercivity (Hc), coercivity of remanence (I%&, saturation magnetisation (MS) and saturation remanence (Mr). The contents of heavy metal, extractable in 2M HN03 (mobile fraction) was determined in samples from every 1 cm layer of each profile according to Swiss methodology (Commentary on...,1987). The samples were determined on Perkin Elmer Atomic Absorption Spectroscope. The selenium content extractable in aqua regia was determined in 15 samples with increased susceptibility or heavy metal contents. Sample mineralization was done under pressure in closed MDS2000 microwave system. The Se content was determined using AAS methodology (Varian SpectrAA 300 equipped with VGA - 76 section). 3. Results The highest v&es of magnetic susceptibility were measured in the Wegliniec and Izera Bog (Fig. 2a,c). In the Weglinic peat profile the maximum measured value was 39 1 xlO”m%g-’ in the layer 3-4 cm below surface. Two sudden increases in magnetic susceptibility were noticed in the Wegliniec profile. The first one at a depth of 9 cm (dated for the period 1945 - 1955) and the second one at 5 cm (dated for the period 1970 - 1980). A very similar distribution of magnetic susceptibility was observed in the Izera Bog profile (Fig 2~). The maximum susceptibility was observed at 4 cm (180 xlo”m3kg-‘) and the highest increase was observed at 8 cm and 4 cm below surface. Both are related to the same time period as in Wegliniec. The magnetic material present in studied peats exhibits a thin, “wasp-waisted” hysteresis loop which is almost saturated in 300 mT (Fig. 3). Such shape of hysteresis loop is often observed in fly ashes produced by coal burning (Petrovsky et al. 1998). Most of the magnetic fraction in coal-fired fly ash is present in the relatively large grain-size fraction 2 to 50 pm (Strzyszcz et. al. 1996). The shape of hysteresies loop as well as the fresuency dependence of
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Figure 2n. Magnetic susceptibility xlO‘sm%g~‘(black solid line), Mn (pale dotted line), Zn (dark dotted line) and F% (grey solid line) in Wegliniec peat profile. Heavy metal COtWtillppttl
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Figure 2b. Magnetic susceptibility xlO~‘m%g~‘(black solid line), Cd (pale dotted line), Cu (dark dotted line), Ni (lined line) and Cr (grey solid line) in Wegliniec profile. .Heavy metalcontentinppm
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Figure 2c. Magnetic susceptibility x109m3kg’ (black .&id line), Mn @ale dotted line), Zn (dark dotted line) and Pb (grey solid line) in Izera Bog profile. Heavy metal content in PPm
Figure 2d. Magnetic susceptibility xlO‘xl%g-’ (black solid line), Cd (pale dotted line), Cu (dark dotted line), Ni (lined line) and Cr (grey solid line) in Izera Hog profile. Heavy metalcontentinppm
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Figure 2f. Magnetic susceptibility x104m%$ (black solid line), Cd (pale dotted line), Cu (dark dotted line), Ni (lined line) and Cr (grey solid line) in Myszkow peat profile. Heavy metal content in ppm
Figure 2e. Magnetic swceptibilii xlo’8m?cge’ (black solid line), Mn (pale dotted line), Zn (dark dotted line) and Pb (grey solid line) in Myszkow peat profile. Heavy metal contentinppm
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Figure 2g. Magnetic susceptibility x10-9m3kg-’ (black solid line), Mn (pale dotted line), Zn (dark dotted line) and Pb (grey solid line) in Kampinos NP peat profile. Heavy metal COllhltillppm
Figure th. Magnetic susceptibility xlO*m3kg-’ (black solid line), Cd (pale dotted line), Cu (dark dotted line), Ni (Iii line) and Cr (grey solid line) in Kampmos NP peat profile. Heavy metal content in ppm
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Figure 2i. Magnetic susceptibility xlO-gmw’ (black solid line), Mn (pale dotted line), Zn (dark dotted line) and Fb (,.s-elid line) in W&sate peat profile. Heavy metal content
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Figure 21. Magnetic susceptibility x10-‘m3kg-’ (black solid line.), Cd (pale dotted line), Cu (dark dotted line), Ni (Iii line) and Cr (prey solid line) in Wolosate peat profile. Heavy metalcontentinppm
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Figure 2k Magnetic susceptibility x104m3kg* (black solid line), Mn (pale dotted line), Zn (dark dotted line) and Pb (grey solid line) in L&a peat profile. Heavy metal content in ppm
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Figure 21. Magnetic
susceptibility x104m3kg’ (black solid line), Cd (pale dotted line), Cu (dark dotted line), Ni (lined line) and Cr (grey solid line) in L&a peat profile. Heavy metaicontentinppm
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Peat Bogs
l,OOE-05
magnetic susceptibility which, with one exception is between 2.0 and 3.3 % (Tab. I), suggests that the susceptibility in studied peats is controlled by anthropogenic ferrimagnetic minerals derived from dust pollution (Magiera and Strzyszcz 2000, Magiera et al., 2000). Coercivity m) in the Izera peat is between 10.2 and 14.8 mT (average 11.5 mT) whereas in Wegliniec peat between 8.1 and 10.8 mT (average 9.7mT) (Tab. 1). It confirms the observations of Flanders (1994) that Hc decreases with distance from the source of fly ash emissions. In case of Izera Bog profile a similarity between susceptibility and lead distribution is observed, especially in the upper part (Fig 2~). Absence of such similarity between susceptibility and Zn suggests remote sources of pollution. Lead is present in higher amounts then zinc in industrial aerosols, which are transported on long distances. A considerably lower correlation between magnetic susceptibility and Pb content (0.41) in Wegliniec may suggest a more local character of pollution (Strzyszcz 1999). In both peat profiles, a relationship between magnetic susceptibility and Cu is also observed (Fig 2b,d). The maximum in Cu concentration in Wegliniec and Izera peat profiles is more or less at the same depth as that of the susceptibility value and both curves are remaining parallel. The maximum measured magnetic susceptibility in Myszkow and Kampinos profiles is about 60 x10am3kg-’ and the distribution in the profile is slightly different (Fig 2e,g). The first noticeable increase in susceptibility is at 12 cm in Myszkow and at 10 cm in Kampinos, but 2 local maxima were also observed. In Myszkow, the first maximum is observed between 9 and 6 cm and in Kampinos at 8-7 cm. The second maximum in Kampinos is at 5 whereas in Myszkow at 4 cm. The secondary maxima are observed in the same layer as in the Wegliniec and Izera Bog. They are dated to 197Os, the period of highest dust emission in Poland. The first maximum in Myszkow dates
I--/--
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Figure 3. Hysteresis loop of smples f&m the strongest magneticly peat layers. a) Izera Bog, b) Wegliniec peat
between 1940-1950 and is probably connected to the postwar industrial&ion and intensive exploration and processing of Pb and Zn ores in Bytom and Olkusz areas, located about 30 km from the sampling site. The evidence for this is an extreme high content of heavy metals (especially Pb), which decreases in the upper layers, even in 4 cm depth, where the second susceptibility maximum, related to deposition of dust derived from intensive electricity production in 197Os, is observed (Fig. 2e) The second susceptibility maximum in Kampinos is also
Table 1. Magnetic chat-a&xi& of anthmpogenic particles present in peats from south-western Poland. Sample no Study area 7.fd (!z) (z-) ( lO-G3kg-l) % 11 117 4.0 10.3 26.3 I2 136 3.3 10.8 26.2 I3 32 2.1 14.8 26.8 Lzera Bog I4 175 2.0 10.6 26.3 I5 17 2.3 11.3 26.3 Wl w2 w3 w4 w5
l
8.1 9.2 10.5 10.8 10.0
23.1 23.3 25.2 25.7 25.0
MS (mAm’kg_‘) 40.1 114.4 36.8 110.4 41.8
Ml (mAm’kg~‘) 9.6 21.7 7.1 19.5 6.2
125.4 239.5 190.6 49.4 14.7
20.7 41.6 35.7 9.3 2.6
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combined with increase in Cy Cr, Cd and Pd content (Fig. 2g,h). Dating again suggests the period of 1940 - 1950 or 1950 - 1960 - the post-war industrialisation in Warsaw. Peat profiles from Wolosate Bog (Bieszczady Mts.) and Leba (Slowinski National Park) reveal a very low magnetic susceptibility (8 - 10 xlO”m%g“, however increased emission in 1970s is observed as a distinct increase in magnetic susceptibility at 5 cm below the surface (Fig. 2i,k). In the lower layers a stable, slightly negative susceptibility was observed. In spite of the very low susceptibility also an increase of Zn, Cu, Cd and Mn in case of Wolosate (Fig. 2ij) and Zn and Cu in case of Leba (Fig. 2k,l) was noticed. In the uppermost layers from Wolosate profile the Zn dominates over Pb. The Zn content decreases downwards the profile to a value of 4 mg/kg. The selenium content which was determined in 15 samples taken from peat layers with increased magnetic susceptibility or heavy metal content from each locality except Leba was between 0.094 mg/kg in the uppermost layer from Kampinos peat bog and 2.663 mgikg in the 3-4 cm from Wegliniec, which was the most magnetic sample recognised during this study (Tab. 2). The correlation coefficient between magnetic susceptibility and selenium content was 0.66.
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Table 2. Selenium content in some peat layers. Depth below Suscgptibility Peat locality ( 10gm%g.‘) surface
-m Izera Bog Izera Bog Izera Bog Izera Bog Weliniec Bog Welinkc Bog Weliniec Bog Weliniec Bog Weliniec Bog Kampinowx NP Kampinows NP KampixwsNP Myszkbw WdOSh
63.0 62.6 69.8 32.1 -1.2 85.2 180.4 252.8 27.7 0.6 2.2 26.0 13.9 48.3 12.3
o-1 cm 3-4cm 6-7 cxn 8-9 cm 12-13 cm o-1 cm l-2cm 3-4czn 5-6cm 9-10 cm o-1 cm 4-5cm 7-8 cm 5-6cm 1-2 cm
Sew&d (mm) 0.98 0.855 0.192 0.631 0.426 0.143 0.614 2.563 0.854 0.647 0.094 0.271 0.727 0.239 0.853
Correlation coefficient 0.661
and Easter Saxony may influence this area. Strong predominance of Pb over Zn in Izera Bog suggests remote source of pollution. Decrease in Hc of magnetic material from Wegliniec as well as less distinct predominance of Pb over Zn suggest both long-distance and local effects, the local effect being here stronger because the peat bog is situated very close to the city of Wegliniec.
4. Disarssion 5. conclusions Magnetic susceptibility in ombrothrophic peats located in open areas is lower then in forest soils. This is a result of the accumulation ability of forest stands. The enhanced magnetic susceptibility in ombrothrophic peats seems to be the result of anthropogenic magnetic particle deposition only, because in the lower peat layers the susceptibility is very low or even negative, which is characteristic for “clean” diamagnetic organic matter. On the base of this assumption, the degree of dust pollution impact for open peat bogs and surrounding areas can be estimated as fallow: < 20 x10‘8m%gV’low moderate 20 - 50 x10”m3kg-’ > 50 x10*m3kg-’ high According to Thompson and Oldfield (1986) the maximum susceptibility for mostly sediments is 20 xlOam%g-‘, so the level below can be consider as a natural level for sedimentary material in peat bog. In each case with susceptibility exceeding 50 xlO‘*m%g“, the concentration of at least one pollutant is over an acceptable level (according the national standards). In case of Wegliniec, Izera and Myszkow, Pb exceeds 100 mg/kg, which is the acceptable level for soil in Poland. The higher degree of environmental hazard in southwestern part of Poland is probably caused by the large Turow Power Plant, which started its operation and emissions in early 195Os, period related (according to C-14 dating) to a first sudden increase of susceptibility in Izera and Wegliniec Bogs at 8-9 cm. Additionally, the longdistance pollution transport from North-Western Bohemia
1. Magnetic SusceptibiliQ in ombrothrophic peat bogs from open area is about 10 - 50 times lower then in surrounding forest soils. It results from the lower accumulation ability of peats as compared to forest stands. The tree canopy plays an important role in capturing the dust pollutants from the air and its accumulation in the topsoil. 2. The highest magnetic susceptibility, heavy metal and selenium contents were observed in peat bogs located in the south-western part of Poland close to the Czech and German border and they result from long-distance pollution even enhanced in some cases due to additional local sources. 3. In spite of sometimes very low magnetic susceptibility, a sudden increase of its value due to anthropogenic input can be easily recogniscd at depths of 5 - 8 cm depending on local conditions. This effect can be observed over the whole of Poland, even in relatively clean areas. This may be a general effect due to increased emissions in the second part of the 20” century. 4. Magnetic measuremens of ombrotrophic peat seem to be method suitable for obtaining records of spatial and temporal variations in the atmospheric fallout of particulates resulting from industrial (long-distance) and domestic (local) combustion pmsses. 5. Magnetic susceptibility in peat bogs seems to be a good method in estimating the degree of environmental hazard in open areas. In cases where the magnetic susceptibility
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exceeding 50 x10am3kg-‘, the hazard is significant and high concentration of at least one pollutant (including heavy metals) can be expected. Acknowledgements We thank the Committee of Scientific Researches in Poland, which supports this study in the frame of the project “Using of magnetic methods in monitoring of industrial dust immission in open areas based on ombrotrophic peat bog studies” (3 TO9C 036 15). We also thanks dr Francoise Leveque and Prof. Pierre Rochette who helped as during the measurement and interpretation of hysteresis parameters in CEREGE laboratory of University of Aix-Marseille, France in the frame of the POLONIUM scientific exchange program. References 1.
2.
3.
4.
5.
6.
7.
Commentary on the ordinance relating to pollutants in soil (VSBo; of June 9, 1986), Text to the Environmental Legislation, Bern, 1987. Flanders, P.J., Collection, measurements and analysis of airborne magnetic particulates from pollution in the environment. J. Appl. Phys., 75, 5931-5936. 1994. Heller, F., Strzyszcz, Z., Magiera,T., Magnetic record of industrial pollution in forest soils of Upper Silesia, Poland. J. Geophys. Res, 103, 17767-17774, 1998. Jungner, H., Sonmnen, E., Possnert, G., Tolonen, K., Use of Bomb-Produced 14C to Evaluate the Amount of CO2 Emanating from Two Peat Bogs in Finland Radiocarbon, Vol. 37, No 2, 1995. Magiera, T., Strzyszcz, Z., Ferrimagnetic minerals of anthropogenic origin in soils of some Polish national parks. Water Air and Soil pollution., 124, 37-48, 2000. Magiera, T., Strzyszcz, Z., Kapicka, A., Petrovsky, E., Ferrimagnetic minerals of anthropogenic origin in highland peats in south-western Poland and northern Bohemia. Geologica Carpatica. vol 51. no 2. s. 199200,2000. Oldfield, F., Tolonen, K., Thompson, R., History of particulate atmospheric pollution from magnetic measurements in dated Finnish peat profiles, Ambio 10, 185-8, 1981.
8.
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Petrovsky, E., Kapicka, A., Zapletal, K., Sebestova, E., Spanila, T., Dekkers, M,J, Correlation between magnetic parameters and chemical composition of lake sediments from northern Bohemia - preleminary study. Phys. Chem. Earth, 23, 1123-l 126, 1998. 9. Reimann, C., de Caritat, P., Chemical elements in the environment, Springer-Verlag, Berlin, Heidelberg, 1998. 10. Strzyszcz, Z., Ferromagnetic properties of forest soils being under influence of industrial pollution. Air pollution and forest decline. In Proc. 14th Int. Meeting for Specialist in Air Pollution Effects on Forest Ecosystems. IUFRO, Interlaken, pp 201-207, 1989. 11. Strzyszcz, Z., Heavy metal contamination in motmtain soils of Poland as a result of anthropogenic pressure, Biology Bulletin, Vol26, no 6, 593-605, 1999. 12. Strzyszcz, Z., Magiera, T., Magnetic susceptibility of forest soils in Polish - German border area, Geologica Carpatica,vol. 49, no. 4 p. 241-242. 1998. 13. Strzyszcz, Z., Magiera, T., The main sources of chemical degradation of soil in urban areas, Proceedings of First International Conference on Soils of Urban, Industrial, Traflic and Mining Areas, University of Essen, Germany, pp. 695-699,2000. 14. Strzyszcz, Z, Magiera, T., Bzowski, Z., Magnetic susceptibility as indicator of soil contamination in some regions of Poland, Roczniki Gleboznawcze. SUPPL. T. XLIV. Warszawa s. 85-93, 1994. 15. Strzyszcz, Z., Magiera, T., Heller F., The influence of industrial immissions on the magnetic susceptibility of soils in Upper Silesia, Poland Studia geoph. et geod., 40,276 - 286. 1996. 16. Thompson R., Oldfield F., Environmental magnetism. Allen and Unwin, London, 1986. 17. Tolonen, K., Oldfield, F., The record of the magneticmineral and heavy metal deposition at Regent Street Bog, Fredicton, New Brunswick, Canada, Phys. Earth Planet Int. 42, 57-66, 1986.