The appraisal of snow sampling for environmental pollution valuation

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The appraisal of snow sampling for environmental pollution valuation

VALERY BARCAN AND ANNA SYLINA
Lapland Biospheric Reserve, Zeleny, 8, 184280, Monchegorsk, Russia; Murmansk Regional Laboratory of Archangelsk Forest Institute, 184280, Monchegorsk, Russia
(Received 25 May, 1992; accepted 5 March, 1995)

Abstract

The snow sampling as well as nickel and copper determination were realized during winter seasons 1987, 88 and 89 years, in Kola Peninsula at area about 4000 km2 affected by industrial emissions of big nickel-copper plant "Severonickel" Smelter Complex situated in latitude 68° N, altitude 31° E. All investigated territory is found contaminated by nickel and copper by the factor 6-1500 times more than the European background, dependently for the distance and direction from the pollution source. The metal accumulation by snowpack is found considerably dependent upon meteorological conditions due to the metal leaching from snow during thaws and winter rains. Accordingly a snow sampling is inapplicable for a pollution monitoring in the subarctic seaside climate, because it may lead to false conclusions. This method may be useful only for reconnaisans, initial valuation of the unknown territory pollution.

Key words: Snow, sampling, applicability, nickel, copper, contamination, valuation.

Introduction

The sampling and the chemical analysis of snow (below - the snow sampling) is evidently the most old and wide-spread method of environmental pollution valuation in high latitudes (look generalizations - Vasilenko etal.,1985; Glazovsky etal., 1985; Anonymous..., 1988; Kryuchkov and Makarova, 1989). Nordenskiold used this method in Arctic and actively popularized it in the seventies of the last century (Nordenskiold, 1875). However the simplicity and availability often result in exaggeration of the method and uncritical unterpretation of findings. A series of researches (Hornbeck et a/., 1977; Johannessen and Henriksen, 1978; Jeffries and Snyder, 1981; Johannes et al., 1984; Fedoseeva et al, 1986; Ratkin and Tereshchenko, 1988) have shown that indefinite part of accumulated mineral admixtures during a winter is leaching from a snow, moves down and reaches the upper soil layer. Johannessen and Henriksen (1978) have shown that 50-80% of mineral admixtures are released in the first 30% of the meltwater. Cadle and Dash (1984) have found an average of 52% of the ions were released in the first 17% of the snowmelt. The main reasons are the fluctuations of temperature, thaws and winter rains. The mineral admixtures move down upon the snow thickness even in sharply continental cold climate of Jakutia (Anisimova, 1980). Evidently usual snow sampling method, i.e. cutting of snow column by whole depth in the end of winter - gives indefinite but always understated result comparatively of real entrance of admixures in snow.

Water, Air, and Soil Pollution 89: 49-65,1996.
© 1996 Kluwer Academic Publishers. Printed in the Netherlands.

The first goal of work was to study the applicability of snow sampling for valuation of environmental pollution by nickel, copper and sulfate-ion in conditions of subarctic maritime climate. The second goal was to receive the reference findings concerning the entrance of these pollutants on the landscape in the zone of emission influence of big metallurgical plant, namely Severonickel Smelter Complex.

2. The Site

The investigated area is situated in Kola Peninsula, 68-69° N latitude and 30-32° E longitude, around the town of Monchegorsk and in the territory of Lapland Biospheric Reserve. In this region the cloak of snow remaines 180 days per year in the mean. A snow thickness in a forest reaches 100-130 cm to the begining of April (Yakovlev, 1961). Thanks closeness of open sea and of the warm Gulf Stream the thaws and winter rains are ordinary occurence. The weather report by investigation period is adduced in Table I. The average annual wind rose is shown in Figure 1, the meridional winds are prevailed. The share of north winds during winter was 5-7% more than in the snowless period. The copper-nickel metallurgical plant Severonickel Smelter Complex is big local source of pollutants, continually working during 45 years. The main emissions in the ambient atmosphere are the sulfur dioxide and nickeli-ferous and copper-bearing dust. During the investigation period emissions were stable (thousands tonnes per annum):

3. Materials and Methods

The snow samples were collected in the end of March or beginning of April, during three winter seasons, namely 1986-87,1987-88 and 1988-89 years. All sampling plots (39 in number, see Figure 1) were in a forest at a height 150-200 m above sea level. The snow was taken from a whole thickness by a special snow sampler, which enables us to collect the samples without the diging of prospect-holes (Sypko and Barcan, 1993). The snow sampler was used firstly just in this work. It was made by the polyethylene pipe of diameter 100 mm, furnished with the special lock on the sharp edge. The sample of 6-10 kg weight was prepared from 4-13 columns in each sampling plot, depending of snow depth. The snow was poured in plastic bags and was kept in the frozen state (in snow pit) up to laboratory treatment. The snow was thawed in big glass funnel, the water flowed down in the lesser funnel having close paper filter. The filtrate flowed down in the glass receiver. After volume measurement the filtrate was steamed to volume 500 ml. Outside inclusions were moved off the sediment by pincers. The filter with sediment was dryed and without weighing was ashing wholly in the muffle by 400-500°C. Nickel and copper contents were determined in filtrate and ash by colorimetric methods - nickel with dymethylglioxym and copper with lead dyethyl carbamate. Sulfate-ion was determined in filtrate by turbidimetric method with barium sulfate. Results were attributed to total area of cross-section of gathered columns and accumulation in g km-2 day-1 was calculated.

Table I Meteorological conditions. Monchegorsk meteorological service station
Date	Air temperature ⁰С		Date of sampling	Date of sampling	Date of sampling	Date of sampling	Date of sampling	Average maximum	Average minimum	Absolute maximum
Date	Average monthly	Absolute maximum	Date of sampling	Date of sampling	Date of sampling	Date of sampling	Date of sampling	Average maximum	Average minimum	Absolute maximum
Winter 1986-87
1986 Dec	- 17.4	+ 0.8	1	2	0	0	- 19	- 13	- 25	0
1987 Jan	- 17.1	+ 5.0	9	0	0	0	- 18	- 13	- 24	0
Feb	- 15.3	- 1.6	0	0	0	0	- 17	- 12	- 22	- 3
Mar	- 9.5	+ 2.1	5	5	2	2	- 10	- 5	- 16	+ 3
	Av-14.8	E 6.3	E15	E7	E2	E2	Av-16	Av-11	Av-27	E 0
Winter 1987-88
1987 Dec	- 13.6	+ 2.3	3	2	2	2	- 15	- 10	- 21	- 0
1988 Jan	- 11.2	+ 4.4	4	2	2	2	- 13	- 8	- 18	+ 1
Feb	- 12.0	+ 0.1	0	0	0	0	- 12	- 9	- 17	- 0
Mar	- 8.8	+ 2.7	4	1	0	0	- 10	- 5	- 15	+ 2
Apr	- 3.8	+ 6.3	11	14	10	28	- 4	+ 3	- 9	+ 12
	Av-9.9	E18.8	E22	E19	E14	E32	Av-11	Av-6	Av-16	E+ 15
Winter 1988-89
1988 Dec	- 13.4	+ 2.9	3	0	0	0	- 14	- 10	- 21	- 0
1989 Jan	- 8.4	+ 4.5	5	2	2	6	- 10	- 7	- 16	+ 2
Feb	- 8.3	+ 1.1	5	0	0	0	- 10	- 6	- 14	- 1
Mar	- 2.8	+ 5.1	17	5	1	5	- 4	- 0	- 9	+ 3
	Av-8.2	E13.6	E30	E 7	E 3	Ell	Av-9.5	Av-5.8	Av-15	E+ 4

4. Results

Tables II and III summarize the result of metals and sulfate-ion accumulation in snow. Metal contents in snow are extraordinarily great. Within the distance ~ 20 km to North and South from Smelter the nickel and copper accumulation in snow reached 2,000-3,000 g km-2 day-1. Aside of emissions plume, e.g. to WNW the quantities are one-two orders less. The snow contamination by metals decreased rather appropriately along the emissions plume, variations are due by terrain factors - Figure 2. The small changes of contamination level were found to direction perpendicular to emission plume - Figure 2. In close vicinity of Smelter, within 5-7 km, the metal entrance little depended from geographic orientation of plots - compare plots 1, 6, 7, 8 and 2, 3, 11, 12, 13 (Table III).

On the base of obtained data it is possible approximately choose the zones of pollution in the investigated territory. The cordon Kupes accepted the reference area. Five zone - Figure 1 - are chosen by excess of nickel snow accumulation over the reference:
1 - > 200 - extraordinary contamination
2 - 50-199 - very strong
3 - 15-49 - strong
4 - 2-14 - moderate
5 - 1 - reference

The territory of the town of Monchegorsk and its vicinity and the belts to South and NNE from the Smelter are contaminated extraordinarily and very strong. East and South-East outskirts of Lapland Reserve are contaminated up to strong and very strong level. The West part of Lapland Reserve is contaminated to moderate level. The share of water-soluble metal of total snow accumulation is shown in Table IV.
This shows it's not enough to analyse a snow filtrate only. It was found no essential difference of water-soluble metal share in polluted and pure areas.
pH of snow melt-water was rather high - 4-6, and it was found no essential connection between snow contamination and pH.
The fluctuations of sulfate accumulation level by snow in greatly polluted areas were the same of nickel and copper - Figure 2. In the same time the sulfate accumulation remains high in rather pure areas, where metal accumulation decreases hundreds times. For example, the sulfate accumulation near cordons Vuva and Kupes in season 1987-88 was only 2-3 times less than in extraordinarily polluted areas near Smelter - Table III. Metal accumulation in these pure sampling plots was 100-250 times less than close Smelter - Table III. The difference of metal accumulation during different seasons are noticed being reached 3-5 times (Table III and V). The quantity and chemical composition of dust and gaseous emissions by Severonickel Smelter Complex were invariable during these years.

Table II
Snow meltwater. Metal concentrations and pH

Plot No Position in relation to Smelter Location Sampling date pH Concentration mcg/1 Ratio SO₄ Ni+Cu

distance km azimuth (°) nickel copper sulfate ion

1 2 3 4 5 6 7 8 9 10

1 6 65 Forest Station Highway Murmansk-Peterburg: 03.87 6.25 260 420 6250 9.2

2 10 45 128 km 03.87 5.60 870 1680 6500 2.5

04.88 780 590 8200 6.0

03.89 534 530 820 6400 4.7

3 12 45 126 km 03.87 4.65 630 1400 5300 2.6

04.88 440 250 5400 7.8

03.89 5.11 360 360 4400 6.1

4 20 45 118km 03.87 5.80 150 200 3200 9.1

04.88 70 50 3700 30.8

03.89 4.13 60 70 2800 21.5

5 30 55 Road Olenegorsk-Lovozero, 5 km 03.87 6.15 35 60 4000 42

04.88 15 10 3100 124

03.89 4.93 20 10 2600 87

6 4 80 Moncha settl. 03.89 5.37 410 230 4500 7.0

7 5 80 Moncha settl. 03.89 5.92 240 200 3400 7.7

8 6 80 Moncha settl. 03.89 5.88 220 160 3600 9.5

9 12 125 Rij-bay settl. 03.89 4.78 40 40 2400 30

10 3 205 Highway Murmansk-Peterburg: 142 km 04.88 5.33 1700 450 6730 3.1

O3.89 4.82 1160 350 4500 3.0

11 14 190 151 km 03.87 4,65 270 790 3100 2.9

04.88 150 110 3600 14.0

03.89 3.85 150 140 2600 9.0

12 16 180 153 km 03.87 3.85 230 740 2900 3.0

13 20 180 157 km O3,87 4.13 210 540 2900 3.9

14 23 180 160 km 03.87 З.8З 250 1280 380O 2.5

04.88 150 350 4000 8,0

03.89 4.92 110 160 2500 9.3

15 27 175 Lake Kisloye 5 km road to Apatity 03.89 5.22 40 50 2800 3.1

16 32 185 Highway Murmansk-Peterburg: 169 km 03.87 4.95 45 260 2000 6.6

04.88 40 80 3500 29

O3.89 5.43 30 30 2000 33

17 34 190 179 km 04.88 50 60 2700 25

03.89 5.85 20 20 1600 40

18 34 195 Chuna settl. Seyd-luht (Chuna-lake) 04.88 30 30 2130 36

19 32 210 Squirrel izba 04.88 3.73 10 10 1700 85

20 31 230 (Chuna river) 04.88 4.65 7 6 1500 115

21 41 230 Cordon Nyavka 04.88 20 8 1900 68

22 49 240 Cordon Mavra 04.88 10 8 1900 106

03.89 4.43 4 1 1600 320

23 53 220 Dolgoe lake 04.88 30 10 2400 60

03.89 5.40 4 6 1500 150

24 80 245 Ena settl. 04.88 90 10 2100 21

03.89 5.43 3 3 1800 300

25 80 245 Ensky settl. 04.88 50 5 2000 36

26 23 255 Sylp-Way 04.88 5.43 3 4 1270 181

27 49 260 Telg-vyd hill 04.88 6 4 1600 160

28 64 265 Cordon Liva 04.88 5 4 1300 144

29 75 280 Cordon Vuva 04.88 5.87 4 4 1800 225

03.89 5.00 2 3 1400 280

30 23 285 Tashkim lake 04.88 4.45 7 5 1800 150

31 36 295 Cordon Kupes 04.88 6.15 3 1 1000 250

03.89 3.73 2 2 1100 275

32 50 295 Nyavka lake 03.89 4.17 4 4 1700 213

33 83 295 Cordon Poos 04.88 6.20 6 8 1500 107

03.89 4.27 5 8 1600 123

34 60 305 Koyst lake 04.88 5.15 3 3 1200 200

03.89 5.87 5 9 1600 114

35 10 330 Yarva river 03.89 5.03 200 170 2900 8

36 17 325 Cordon Red Lambina 04.88 5.55 15 10 2000 80

03.89 5.75 20 10 1800 60

37 55 330 Kutskol settl. 03.89 4.85 6 10 2000 125

38 35 345 lakes isthmus 03.89 5.63 70 70 2300 16

39 20 0 (Moncha lake) 03.89 5.40 230 260 2800 6

Table III
Amount of nickel, copper and sulfateion in snow

Plot No Plot position in relation to Smelter Sampling date Quantity of metals and sulfateion by accumulation period Calculated entrance in forest litter

km (°) gkm^-2 /day^-1 - rngkg" Vyr"1

nickel total copper total sulfateion in filtrate nickel total copper total

1 6 65 03.87 1980 1000 3570 230 112

2 10 45 03.87 3633 2500 4340 416 270

04.88 1404 840 4650 153 92

03.89 3876 2590 4540 452 284

3 12 45 03.87 2573 1827 4000 300 196

04.88 1099 490 3000 120 54

03.89 1809 1096 6030 212 121

4 20 45 03.87 487 313 2420 56 33

04.88 198 129 2340 22 14

03.89 442 220 4090 52 24

5 30 55 03.87 160 187 3160 20 20

04.88 48 42 1520 5 5

03.89 80 46 3200 9 5

6 4 80 03.89 3162 965 7000 372 110

7 5 80 03.89 1542 623 5060 180 69

8 6 80 03.89 1460 615 6610 169 68

9 12 125 03.89 296 145 3470 35 16

10 3 205 04.88 9500 2065 7830

03.89 10790 2075 10350 1247 233

11 14 190 03.87 1327 1007 2730 155 105

04.88 493 273 2790 54 29

03.89 780 353 3770 90 38

12 16 180 03.87 1313 1187 3130 151 122

13 20 180 03.87 1340 1227 3840 154 129

14 23 180 03.87 2360 2733 5870 273 278

04.88 768 735 5250 83 80

03.89 1021 631 6170 151 67

15 27 175 03.89 411 232 5180 48 27

16 32 185 03.87 483 627 2500 57 67

04.88 310 213 4450 34 23

03.89 365 174 4750 42 20

17 34 190 04.88 155 91 2210 17 10

03.89 231 99 3440 27 11

18 34 195 04.88 140 89 2200 16 11

19 32 210 04.88 47 31 1600 6 4

20 31 230 04.88 25 19 1310 3 2

21 41 230 04.88 87 42 1210 10 4

22 49 240 04.88 30 16 1440 4 2

03.89 43 37 2760 5 4

23 53 220 04.88 38 15 1320 6 2

03.89 46 24 2340 6 3

24 80 245 04.88 115 22 740 13 2

03.89 32 18 2130 4 2

25 80 245 04.88 123 17 480 13 2

26 23 255 04.88 13 11 1260 1.5 1.3

27 49 260 04.88 35 26 1720 4 3

28 64 265 04.88 18 13 980 2 1.5

29 75 280 04.88 5 6 1360 0.5 0.7

03.89 19 12 2670 2 1.5

30 23 285 04.88 29 20 2610 3 2

31 36 295 04.88 8 7 910 1 1

03.89 16 12 2430 2 1.5

32 50 295 03.89 48 30 4560 6 3

33 83 295 04.88 21 19 1390 2 2

03.89 36 31 3560 4 4

34 60 305 04.88 14 10 1050 1.5 1.2

03.89 45 32 3050 5 3

35 10 330 03.89 925 401 3690 119 43

36 17 325 04.88 62 27 1340 7 3

03.89 152 81 3900 17 9

37 55 330 03.89 68 43 4290 8 5

38 35 345 03.89 304 152 2450 35 17

39 20 0 03.89 1482 714 3880 172 79

Table IV
Share of water-soluble metal of total snow accumulation (%)

Ni Cu

1987 16 ± 1.3 53 ± If

1988 27 ± 2.4 33 ± 13

1989 24 ± 0.9 45 ±8

5. Discussion

It is possible to compare the metal entrance in most pure parts of Lapland Reserve, namely near cordons Vuva and Kupes, with any background region far from metal emisions sources. This permits to imagine the scale of landscape pollution by nickel and copper. The annual entrance of nickel near Valdai (the centre of Russia) was found 1 kg km-² year-¹, and the same of copper - 3-4 kg km-² year-¹ (Alexeenko, 1988). The nickel entrance near cordons Vuva and Kupes (calculated by Table V) was found in winter 1988-89 6-7 kg km-² year-¹, i.e. 6-7 times more the background of Russia centre. This corresponds with data of Makarova (Kryuchkov and Makarova, 1989) about total pollution of Kola Peninsula by heavy metals.

Sulfate-ion is accumulating in a snow as a result of absorption of atmospheric sulfates and sulfur dioxide by snow crystals in upper atmospheric levels. The place of accumulation can be remote very much from the place of snow fall-out (Vasylenko et al., 1985). The transfer of salts from surface of open ocean is possible too, its share naturally is identical in all parts of investigating territory. The metals, on the contrary, get in snow mainly in form of dust emitting, in our case, by furnaces of Severonickel Smelter Complex. The distribution of these pollutants in space depends on the size of dust particles.

It is possible to prove the absence of connection between nickel, copper and sulfate-ion in a snow by the ratio of total sulfate and nickel-copper in a snow melt-water (Table III). The ratio sulfate - metal in salts NiSC>₄ and Q1SO₄ is 1.63 and 1.51 respectively, at the same time this ratio near Smelter was 6-40, and in far areas, where the metal entrance was essentially less, the ratio reached 100-300. We consider that the different content of metals found in snow in different seasons at the same sampling plots results from washing of water-soluble metal salts out of snow cover during thaws and winter rains. Average temperatures and thaws, frequency and duration of rains were essentually different during observed seasons - see Table I. The winter 1986-87 was cold and the winter 1988-89 was extraordinarily warm. The winter 1987-88 up to April was less differed from one of 1986-87, but in beginning of April 1988 rain duration was 28 hours, and snow was got soaked to the soil.

The connection was not found between meteorological conditions and the release of sulfate-ion out of snow - Table V. Sulfate anions absorbed by snow cristals from atmosphere are distributed more or less upon all tickness of snow grains. For this reason the surface moistenning doesn't decrease the sulfate concentration in a snow.

We have the reason to consider that a quantity metals falling on the ground surface and calculated by snow chemical analyses is less that real one in result of natural washing out of snow. Of course if it would be possibly to establish the snow collector isolated from the soil, the results would be nearer to a reality. But we don't know the satisfactory construction.

It's possibly to calculate the nickel and copper entrance in the upper soil layer being based on obtained data. Some preliminary conditions. The metal entrance on the landscape in the unit of time is constant during a year, independently of the season. This condition follows from the constancy of smelter emissions during a year. This permits to extend the results obtained for snow period on the whole year.

The metals being in water-soluble forms remain in soil wholly during snow-less period; but ones, accumulated in snow, devide by half-and-half (Molchanov, 1973), namely half remains in soil, and half goes out during the spring melting of snow. On the contrary the water-insoluble forms fallen on a landscape both during snow and snow-less seasons remain in soil wholly.

The accepted conventional signs are:

The calculation shows (Table III) the annual accumulation of metals in a top soil not less 4-9 times exceeds the background metal concentration in radius 10-12 km from Smelter, and not less 2 times at distance 30-40 km to South and to North. The regression of calculated metal deposition to the real content of metal in A0 horizon is shown in Figure 3. The metal concentration data in soil are borrowed from (Barcan et aL, 1993). The different angles of slope are in result of different metal accumulation in snow during different seasons.

Table V
Fluctuation of pollutants accumulation by snow in different years

Plot No. Nickel Accumulation gkm²/day^-1 Ratio Copper Accumulation gkm²/day^-1 Ratio Sulfate-ion Accumulation gkm²/day^-1 Ratio

1986-87 1987-88 1988-89 1986-87 1987-88 1988-89 1986-87 1987-88 1988-89

2 3630 1400 3880 1:0.4:1.1 2500 840 2590 1:0.3:1.0 4340 4650 4540 1:1.1:1.0

3 2570 1100 1810 1:0.4:0.7 1830 490 1100 1:0.3:0.7 3400 2800 6035 1:0.8:1.8

4 490 200 440 1:0.4:0.9 315 130 220 1:0.4:0.7 2420 2340 4090 1:1.0:1.7

5 160 50 80 1:0.3:0.5 190 40 45 1:0.2:0.2 3160 1520 3200 1:0.5:1.0

11 1330 490 780 1:0.4:0.6 1010 275 355 1:0.3:0.4 2730 2790 3770 1:1.0:1.4

14 2360 770 1020 1:0.3:0.4 2735 735 630 1:0.3:0.2 5870 5255 6170 1:0.9:1.1

16 480 310 365 1:0.6:0.8 630 215 175 1:0.3:0.3 2500 4450 4750 1:1.8:1.9

6. Conclusion

It is found that an investigated territory (about 4,000 km²) including Lapland Reserve area is wholly contaminated with nickel and copper caused by industrial emissions of Severonickel Smelter Complex. The metal accumulation by snow is found considerably dependent on the meteorological conditions due to the metal leaching from a snow during thaws and winter rains. For this reason the snow sampling is unapplicable for pollution monitoring in the subarctic seaside climate, because it can lead to false conclusions. This method is useful only for reconnaisans, initial valuation of the unknown territory pollution.

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