Waste disposal sites as sources of mercury in the atmosphere in the coastal zone of the Gulf of...

Oceanological and Hydrobiological Studies I n t e r n a t i o n a l J o u r n a l o f O c e a n o g r a p h y a n d H y d r o b i o l o g y

Volume 42, Issue 1

ISSN 1730-413X (99–109)

eISSN 1897-3191 2013

DOI: 10.2478/s13545-013-0064-0

Original research paperReceived: Accepted:

February 24, 2012June 06, 2012

Copyright© of Institute of Oceanography, University of Gdansk, Poland www.oandhs.org

Waste disposal sites as sources of mercury in the atmosphere in the coastal zone of the Gulf of Gdańsk (southern Baltic Sea) Lucyna Falkowska, Agnieszka Witkowska1, Magdalena Bełdowska, Anita Lewandowska University of Gdańsk, Institute of Oceanography Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland Key words: Hgtot in soil and water, TGM, burial, modern landfill, Gulf of Gdańsk

Abstract

Elemental mercury re-emission into the air from an old burial ground in Gdańsk Letnica and from a modern landfill in Gdańsk Szadółki resulted in noticeably increased TGM concentrations from the urban background level of 1.9 ng m-3 to a maximum value of 164.4 ng m-3. Hgtot concentrations in the soil of the burial ground ranged from 37.3 to 4817.3 ng g-1 and in the surrounding water: from 22.0 to 55.0 ng dm-3. The highest Hgtot concentrations in the modern landfill (Gdańsk Szadółki) were reported for the unsorted waste: 36.1 - 972.8 ng g-1. Laboratory experiments on the re-emission of Hg(0) into the air showed that emission from soil was stimulated by solar radiation and from the water – additionally by turbulent mixing.

1 Corresponding author: [email protected]

INTRODUCTION

Wastes are produced in every area of life and become a global problem. The increasing size of the population, technological progress, products with a short expiry date, and many others, such as disposable packages - they all cause that landfills and waste become the subject of many research projects, conferences and meetings on economy and politics.

A burial ground can be a specific kind of waste disposal site that is designed to collect expired, non degradable crop protection chemicals and other hazardous products. Waste burial grounds were built in Poland in the last century because there was a problem with the increasing amount of expired, and withdrawn from the use, crop protection chemicals (Ignatowicz 2008a). Burial grounds so far discovered contained also: expired pharmaceuticals (drugs), various types of reagents, packaging such as glass bottles, plastic containers and waste from different workshops (Wolkowicz et al. 2003). Old-generation substances stored in burial grounds were toxic and persistent. Wastes deposited in the examined burial grounds contained 0.7% of mercury compounds. During the removal of the burial ground in Skrzydłowo (Pomeranian Province), for example, about 600 kg of mercury compounds was retrieved (Biziuk 2001).

All the waste burial grounds were similar in their construction. During their formation none of the standards or regulations were followed. Areas allocated for their construction were not examined (Wołkowicz 2003). The only effort made was to select the locations remote from inhabited areas - usually deserted, overgrown wastelands. Most of the burial grounds were constructed on sandy soils with high permeability, so their lack of consolidation could have turned out to be very dangerous to the environment. There were three types of waste burial

100 | Lucyna Falkowska, Agnieszka Witkowska, Magdalena Bełdowska, Anita Lewandowska


grounds: soil pits, concrete objects (round and rectangular tanks), and old military objects (Ignatowicz 2008b, Wołkowicz 2010).

Due to inaccurate documentation of the burial grounds, it is difficult to estimate the real number of such objects in Poland. Eight burial grounds were registered in the Pomeranian Province. However, several more were found in recent years. The burial ground discovered in Gdańsk Letnica in 2009, could be given as an example of such an unregistered object. It was probably built in the first half of the 20th century and was in use until the 1960s.

Modern landfills are different in their structure and character from waste burial grounds. Legal regulations, acts and decree-laws (the Acts of 2001, 2005, 2007, 2008, 2009, the Decrees of the Minister of 16 April 2002, 9 September 2002, 8 April 2003, Journal of Laws No. 165, item. 1359) influence their state and condition, and cause that they are more tight, more protected and controlled than the old ones. Both during the formation of burial grounds and currently at landfills, various hazardous chemicals, including mercury, get to the soil. People do not always comply with waste sorting recommendations for financial reasons, habits, lack of time, or simply ignorance. Therefore, such products as cosmetics, medicines, different kinds of crop protection chemicals, mercury thermometers, fluorescent lamps, batteries and many other items that contain high concentrations of mercury are finally transported to landfills. In that way mercury re-enters the biogeochemical cycle. Despite strong restrictions on the use of mercury in agriculture and other branches of industry, and the reduction of mercury emissions into the atmosphere from burning fossil fuels, no proportional decrease in the mercury concentration in the air has been observed (Pacyna et al. 2006). Re-emissions from land and sea surface as well as from objects used by people (closed factories of paint, varnish and fluorescent lamps; landfills with industrial, municipal wastes and crop protection chemicals) could be considered as the reason for that situation (Bełdowska et al. 2007, Ebinghaus et al. 1999).

Mercury is one of the most hazardous global environmental pollutants. It is chemically and biologically active. This metal is very harmful to health and life of organisms. In the cycle through the air, water, soil and living organisms, mercury is cumulated at each level of the food web in the most toxic form: organic forms of mercury (Kabata-Pendias and Pendias 1999, Kabata-Pendias 2011). In

the air, Hg occurs mainly in the gaseous form and therefore it has a long life-time. Volcanic eruptions and evaporation from the land and ocean surface are the main natural sources of mercury. Anthropogenic sources include burning of coke, lignite and coal, as well as cementing and waste disposal (Hławiczka 2009).

The primary objective of this study was to identify sources that, apart from the sea (Wandberg et al. 2001, Marx and Bełdowska 2001, Bełdowska et al. 2007), under certain physical conditions become effective in the emission of mercury into the air during warm months. As the authors assume, both old and modern waste disposal sites in the coastal area might become the re-emission sources of mercury to the atmosphere during summer. Additional laboratory experiments conducted on water and soil samples from the waste disposal sites allowed to determine how the external conditions such as solar radiation and wind affect the re-emission of mercury. Such re-emission probably took place for about a dozen years during the existence of the old burial ground in Gdańsk Letnica and still takes place at the modern landfill in Gdańsk-Szadółki. MATERIALS AND METHODS Measurement sites

The study included two types of waste disposal sites: the old burial ground and the modern landfill in the outskirts of Gdańsk (Fig. 1).

The burial ground was located in Gdańsk Letnica, about 3 km in a straight line from the Gulf of Gdańsk and about 1.5 km from the Port of Gdańsk. The burial ground (Fig. 2) had an area of approximately 260 m2 and was up to 5 meters thick. About 3 000 tons of waste were removed from the ground. In July 2009, during waste removal, soil and water samples were being collected for 4 weeks from a surrounding drainage ditch (from the first to the last day of the burial ground removal). The collected soil contained wastes such as glass, plastic elements and organic debris (e.g. roots). That shows the variety of wastes deposited in the ground during several decades of the last century. The collected material consisted mostly of dark brown clay, but also of some dark, dry sand and watery mud.

The landfill in Szadółki − Zakład Utylizacyjny Sp. z o.o. in Gdańsk (Utilization Plant Ltd.)) is located about 10 km in a straight line from the Gulf of

https://www.researchgate.net/publication/38979409_True_Elements_in_Soils_and_Plants?el=1_x_8&enrichId=rgreq-e2d5f9badb3463fc11ee73ad8ca23a46-XXX&enrichSource=Y292ZXJQYWdlOzI1ODA3Mjk2ODtBUzoxMDQyNTkyODY3MzI4MDJAMTQwMTg2ODc1OTE3MA==

Waste disposal sites as sources of mercury in the atmosphere in the coastal zone of the Gulf of Gdańsk| 101

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Gdańsk. In 2010, more than 180 000 tons of waste were stored in that landfill. Sample preparation

Five weighed sub-samples taken from different parts of each sample were further analyzed. Water from the drainage ditch was kept in borosilicate glass bottles in a refrigerator. Prior to taking a weighed sub-sample, the water was mixed by shaking a bottle. Three weighed sub-samples were collected from each bottle.

During each visit at the burial ground site, measurements of total gaseous mercury were carried

out every 10 minutes for 1.5 hour using a portable automated mercury analyzer GARDIS 3. Eleven soil samples and eight water samples were collected (from the drainage ditch) in Gdańsk Letnica, and five 1.5-hour series of TGM measurements were conducted during the whole campaign.

Additionally, half a year after the removal, 3 soil samples were collected from the place where the burial ground was situated and from the surrounding ground.

In November 2010, samples of waste and soil beneath the waste stored were collected from 3 separate areas of the landfill:

• biodegradable waste - S1; • unsorted municipal waste - S2; soil next to

unsorted waste - S3, soil under unsorted waste - S4;

• soil under plastic waste - S5;

The determination of total mercury concentration in soil and water samples was carried out in the Laboratory of Mercury, Institute of Oceanography, University of Gdańsk. It was measured by the atomic absorption spectroscopy method using a mercury analyzer AMA 254. The detection limit was 0.003 ng Hg. To determine the precision of the method applied, the certified reference material was used: GBW07314 Off shore Marine Sediment. The average error value was 3%. Laboratory experiments

The second part of the study included laboratory experiments on the re-emission of mercury from the collected soil and water samples. An automatic gaseous mercury analyzer GARDIS 3 was used to register TGM concentrations. The detection limit for Hg in the air was 0.1 ng m-3 (Bełdowska et al. 2008). The SOL 500 solar simulator was used in the laboratory experiments, as well as: SKYE SKU 420070224484 sensor (in order to measure UV-A ≈14.9 W m-2), EIJKELKAMP SKU4300497-14 854 sensor (to measure UV-B ≈1.68 W m-2) and EIJKELKAMP SKP210/I 089 613 595 sensor to measure the photosynthetically active radiation (PAR ≈482 μmol m-2 s-1). The simulation of aeolian (wind) erosion was carried out by stirring the soil using a Teflon rod. Water was stirred with a motorless magnetic stirrer. Changes in TGM concentrations were measured in each medium (soil and water), in four stages (1E - 4E):

Fig. 1. Location of the waste burial ground in Letnica and the modern landfill in Szadółki (the coastal zone of the Gulf of Gdańsk).

Fig. 2. Burial ground in Gdańsk Letnica during the removal.



1E - stage in a dark room without stirring/mixing, 2E - stage in a dark room with stirring/mixing, 3E - stage of exposure to light using the solar

simulator, without stirring/mixing, 4E - stage of exposure to light using the solar

simulator, with stirring/mixing.

Each stage lasted about 30 minutes and consisted of 4 to 7 measurements. The Teflon tube of the GARDIS 3 analyzer was placed 20 cm above a sample and the air was sucked at a speed of 1 m3 min-1. Before and after each stage of the experiment, temperature of a sample was measured and the concentration of Hg (g) in the laboratory room was registered. Those results were subtracted from the TGM concentrations measured during the experiment.

Soil water content [H] and loss on ignition [LOI] were the additional parameters measured during the experiment.

Experiments on the re-emission of gaseous mercury from soil and water were repeated twice and similar results were obtained. RESULTS AND DISCUSSION

In the coastal region of the Gulf of Gdańsk, where the research on the re-emission of Hg from the burial ground and the modern landfill was conducted, there are probably still unidentified, ”hidden” sources of mercury. Elevated TGM concentrations in the summer air, compared to the urban background, justify such assumptions (Bełdowska et al. 2008). The Tricity (Trójmiasto), together with the neighboring municipalities, is inhabited by almost one million people; it is heavily industrialized, and distinguished by numerous industrial objects: cement plants, power plants, a refinery, a phosphate fertilizer plant, shipyards, ports, main water transport routes and waste incinerators. Also natural re-emission of mercury into the air from the surface water of the Gulf of Gdańsk is observed in the region. TGM over the burial ground

Measurements of TGM in the air were carried out in the vicinity of the burial ground, 10 m away from the burial ground, and also while moving by car through the agglomeration of Gdańsk in July 2009 - in order to measure the urban background

concentration, the average value of which was at that time 1.9 ng m-3. In all five series of measurements, the recorded mercury concentrations were higher in comparison to the background (Fig. 3). However, before starting the work affecting the structure of the burial ground, i.e. on the first day of the measurements, TGM concentrations were only slightly different from the background and ranged from 1.6 to 2.5 ng m-3. During subsequent measurement series, TGM concentrations of 4 - 5 ng m-3 occurred several times. At the end of the work aiming at the final removal of the burial ground (29 July 2009), TGM concentrations were repeatedly reported to be above 10 ng m-3 and the maximum value was >160 ng m-3. At that time the excavator uncovered the deepest layers of the burial ground, soil was loaded onto trucks and transported for utilization. High air temperature (about 24°C), intensive solar radiation and strong winds over a large exposed area caused that concentrations of total gaseous mercury were the highest in the air over the burial ground and had a large range of variation. Such high concentrations of TGM were observed previously only for a short period - during the excavation work in Gdynia (Bełdowska et al. 2006b). In the region of northern Poland, in the cities located near the coastline of the Gulf of Gdańsk, the average TGM concentration in winter ranges from 1.3 ng m-3 in Gdynia to 1.9 ng m-3 in Sopot and Hel. Despite the growing importance of burning fossil fuels, clean marine air masses and storm winds contribute to the dispersion of pollutants. In addition, gaseous mercury is then carried away with the warm air and transported over long distances (Bełdowska et al. 2007). The above-freezing temperatures in winter favor the transformation of gaseous mercury into its aerosol form, which causes a decrease in TGM concentration and an increase in [Hg (p)] (Bełdowska et al. 2011). Higher average TGM concentrations in

Fig. 3. Concentration of total gaseous mercury (TGM) in the air over the burial ground in Gdańsk Letnica during its removal in July 2009.


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the coastal area occur in the summer, when the increasing temperature intensifies the Hg emission from soil and water. Then, the average concentration of TGM in the area of Gdynia, Hel and Sopot is about 2.6 ng m-3, 2.4 ng m-3 and 2.3 ng m-3, respectively (Marks and Bełdowska 2001, Bełdowska et al. 2006a). Those average TGM values are comparable to the concentrations reported in the vicinity of the burial ground during the first four measurement series, i.e. from 9 to 23 of July 2009. The enormous increase in the concentration of TGM on 29 July 2009 was probably due to the release of mercury into the air from the exposed soil layer, which was enriched with mercury more than the other layers. Burial ground - old waste disposal site in Gdańsk Letnica

During the subsequent stages of the burial ground removal, 1-5 samples of soil (G1-G5) and 1-3 samples of water (W1-W3) were collected from the surrounding drainage ditch on the following days: 14, 20, 23 and 29 of July 2009. The average concentration of total mercury in soil samples of varying composition ranged from 37.28 ng g-1 to 4.82 µg g-1 (Table 1). A large dispersion of values was observed for each sample, the relative standard deviation (RSD) amounted up to 127%, which confirmed the heterogeneity of soil samples. Concentrations of total mercury in the soil of the burial ground in Gdańsk - Letnica were higher than in the soil from the vicinity of coal-mining waste dumps, where such waste as gangue or coal slurry is deposited. The content of mercury in coal ranges from 0.01 to 0.15 µg g-1, however, concentrations up to 1.6 µg g-1 also occur (Klojzy-Kaczmarczyk and Mazurek 2010). Klojzy-Kaczmarczyk and Mazurek (2008) measured the concentration of mercury in crude oil and obtained the results within the range of 0.02 - 0.18 µg g-1, which was up to 20 times lower than in the soil of the burial ground. In the soil of the Tri-City Landscape Park, the concentration of mercury is 0.03-0.20 µg g-1. In the Seaside Landscape Park in Wladyslawowo, the mercury content ranges from 0.01-0.09 µg g-1 (Rompe et al. 2008). In the town of Lębork, the content of mercury in forest soil ranges from 0.01 to 0.08 µg g-1 (Mielewska et al. 2008). Taking into account the concentration of Hg and the weight of waste, it was calculated that the mercury content over the whole burial ground did not exceed 15 kg.

Laboratory experiments indicated that the re-emission of gaseous mercury from the soil occurred in all the cases. However, the scale of re-emission was so large that the values of gaseous mercury concentrations over the samples from the burial ground were grouped into two groups (Fig. 4a and 4b). The lowest and most stable TGM concentrations over soil samples occurred during the 1E and 2E stages in a dark room, both with and without stirring. Differences in re-emission of Hg were apparent from the beginning of the experiment (1E) only for the samples with a high water content (D2G4 - 32.98%; D3G1 - 34.32%; D4G2 - 45.77%). That could result from a slow, but steady increase in temperature and a decrease in water solubility of mercury. Stirring introduced in the second stage of the experiment (2E) stimulated the emission of

Table 1 Characteristics of the total mercury concentration (ng g-1) in soil from the burial ground in Gdańsk Letnica in July 2009 (D1G1 - D4G2), in soil and in waste from the landfill in Gdańsk Szadółki in November 2010 (SZS1 - SZS5), in soil one and a half year after the removal of the burial ground, in February 2011 (LS1-LS3) and in water (ng dm-3) from the drainage ditch surrounding the burial ground in July 2009 (D1W2-D4W1).

SAMPLE MEAN ±SD MIN MAX RSD (%)

BURIAL GROUND

D1G1 101.47 ±73.60 38.78 282.90 72.53

D1G2 1300.86 ±567.37 680.80 2169.85 43.62

D1G3 713.60 ±161.74 335.39 848.46 22.66

D2G1 911.41 ±1162.87 92.27 3962.02 127.59

D2G2 219.10 ±107.91 89.41 399.91 49.25

D2G3 351.83 ±246.19 140.24 930.49 69.97

D2G4 364.10 ±112.05 216.50 486.04 30.78

D2G5 437.67 ±241.50 184.43 943.33 55.18

D3G1 3718.57 ±1070.39 2352.22 4817.31 28.78

D4G1 583.45 ±106.44 382.22 723.13 18.24

D4G2 98.38 ±41.66 37.28 174.78 42.35

LETNICA

LS1 564.63 ±157.52 403.37 794.50 27.90

LS2 1176.01 ±315.49 904.38 1633.56 9.15

LS3 5.57 ±0.51 5.09 6.41 26.83

SZADÓŁKI

SZS1 103.29 ±56,64 36.52 170.17 54.84

SZS2 308.72 ±378.21 36.09 972.79 122.51

SZS3 58.36 ±35.55 31.77 120.90 60.92

SZS4 9.58 ±3.17 5.80 14.31 33.05

SZS5 7.91 ±1.38 5.72 9.52 17.42

WATER

D1W2 41.06 ±10.10 33.50 55.00 24.59

D1W3 29.25 ±3.36 26.87 31.63 11.48

D2W1 27.87 ±0.35 27.63 28.13 1.27

D2W2 26.87 ±6.89 22.00 31.75 25.65

D2W3 25.50 ±3.36 23.12 27.87 13.17

D3W1 28.87 ±5.83 24.75 33.00 20.20

D4W1 44.87 ±3.71 42.25 47.50 8.27



mercury from the soil with the highest water content, e.g. D4G2.

The subsequent stage of the experiment (3E) with the exposure to light was characterized by a rapid increase in the concentration of mercury over the soil. The temperature of soil increased by about 11°C during that stage. As a result of the emission, TGM concentrations increased 15 - 50 times (Fig. 4a) in the first group of the samples and 0.5 - 7 times (Fig. 4b) in the second group, compared to the 2E stage. Both groups of soil samples varied in emission by one order of magnitude, and the results reflected the impact of burial ground layers successively uncovered by the excavator.

During the last stage (4E), when the soil was under the influence of two external factors: light (radiation) and stirring (wind), the release of mercury from the soil decreased in most cases (Fig. 4a and 4b). However, a decrease in the emission was very small (D1G1; D2G2; D2G3; D2G4; D4G1; D4G2)

over the soil with low concentration of total Hg and high water content (H) and LOI, while it was sharp over the soil with a high content of mercury, even when the water content or LOI were low (D1G2; D1G3; D2G1; D3G1). Another factor - stirring - probably supports and prolongs the emission resulting from the photoreduction of mercury bonding to organic matter or mercury forming labile bonds with different components of the soil. Nonetheless, without the speciation analysis of Hg in the soil of the burial ground, a thorough assessment of variations in the emission is not possible.

The results of the experiments (Table 1, Figures 4a and 4b) showed that solar radiation had the strongest effect on TGM concentrations over the soil, as then the highest emission of mercury was observed. A large increase in soil and air temperatures caused a rapid increase in concentrations of TGM. However, the Pearson correlation coefficient of TGM concentration and soil temperature showed a moderate correlation (r = 0.44). Similar results were obtained in Slovenia during the research on total gaseous mercury concentrations in the air over the area polluted by mining and extraction. The authors did not provide the Pearson correlation coefficient, but described the relation between the concentration of mercury in the air over the study area and the increasing air temperature (Milkavicic 1999). The studies conducted in France also pointed to the release of mercury when soil temperature was increasing: there was 10 µg g-1 of Hg in a sample at room temperature and the increase of 20°C caused a 4 µg g-1 loss of mercury from a sediment sample (Probst et al. 1999). Sholtz et al (2003) showed the relationship between the increased release of mercury from the soil and the measured solar radiation. Carpi and Lindberg (1998) also observed a strong correlation (r = 0.92 and r = 0.94) between the solar radiation and the concentration of mercury over samples. Modern landfill - Gdańsk Szadółki

Unsorted municipal waste (S2), stored in separate areas/compartments, were characterized by the highest mercury concentrations (36.09 - 972.79 ng g-1, Table 1.) of all the collected samples. People do not always sort the waste properly. No compliance with the accepted standards is the reason why such wastes as fluorescent lamps (with the mercury content of up to 40 mg per one item; Journal of Laws No. 112, item 1206), are transported

a)

b)

Fig. 4. Changes in the concentration of total gaseous mercury (TGM) (ng m-3) during subsequent stages of the experiment (simulation of day/night conditions and wind erosion) over soil collected from the burial ground in Gdańsk Letnica in July 2009; a) group of samples with high re-emission of Hg(0), b) group of samples with low re-emission of Hg (0).


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to the landfill in municipal waste. In the European Union in 2005, the waste such as batteries, dental materials, measuring and control equipment, lighting equipment, electrical and electronic equipment contained 242 tons of mercury (Hławiczka 2008). The research carried out in the Silesia region showed that the average mercury content in municipal sewage sludge was 0.65 µg g-1 (Michalska 2010). High concentrations of mercury also occurred in biodegradable waste (S1). That results from the fact that such type of waste consists mainly of plant remains: grass, roots, tree branches and leaves. Elevated concentrations of mercury may occur in the biological material, as plants absorb Hg through the roots from the soil or through the leaves from the atmosphere. According to the previous study, grass from the area polluted by waste contained 0.04 – 0.06 µg g-1 of mercury, and from the area polluted by the chemical industry – 4 µg g-1 (Kabata-Pendias and Pendias 1999).

The lowest mercury concentrations (5.72 - 9.52 ng g-1) were measured in the soil under the plastic waste (S5). Low concentrations also occurred in the soil under the unsorted waste (S4): from 5.80 to 14.31 ng g-1, even though the average concentration of Hg in the unsorted waste (S2) was about three orders of magnitude higher (Table 1). This reflects the effectiveness of soil protection against the leakage of xenobiotics to the ground from separate compartments of the landfill. The average Hg concentrations, which were one order of magnitude higher in the soil next to the unsorted waste (S3) compared to the soil beneath the unsorted waste (S4), could confirm the protection and indicate another route of mercury migration. In the Utilization Plant Ltd. in Gdańsk - Szadółki, the unsorted municipal waste is currently stored over the area of 12.5 ha. That area is prepared so as to prevent the leachate from entering the ground. The bottom of each compartment is lined with special material to prevent the migration of contaminants. These are precautions against contamination of the ground and groundwater under the landfill with chemicals and other hazardous substances. However, there are no precautions against the release of hazardous substances into the atmosphere.

Experimental measurements of the potential emission of mercury from the soil collected at the landfill in Gdańsk Szadółki showed that for samples S1SZ (biodegradable waste) and S4SZ (soil under unsorted municipal waste), the process occurred with low efficiency (Fig. 5). The concentration of mercury

over those samples did not exceed 10 ng m-3. Despite high levels of Hg in the biodegradable waste (LOI = 8.29%), the re-emission was hardly noticeable during all the stages of the laboratory experiment. Probably there was no mercury present in a labile form, so it could not be released into the air during intense radiation and stirring. Low emission from the soil under unsorted waste (S4SZ) resulted from low Hg concentration in the samples (Fig. 5).

Much higher release of mercury was observed over the samples of unsorted municipal waste (S2SZ), even during the first and the second stage in a dark room (1E, 2E) (Fig. 5). The process was probably favored by the water content (34.07%), which was the highest of all the soil samples collected in Szadółki. Similarly as in the case of the soil from the burial ground (D2G4 and D3G1), mercury contained in wet waste was quickly released. It could be observed in the third stage of the laboratory experiment when solar radiation was included. In that stage of the experiment, the maximum concentration of TGM = 113.90 ng m-3 occurred over the soil collected from under the plastic waste (S5SZ), while the concentration of mercury in the sample, as well as LOI (1.64%) were the lowest. Probably another factor, e.g. larger contribution of mercury present in a labile form combined with dissolved organic carbon, was more important in the emission of mercury to the air than LOI or water content parameters. The speciation analysis could have helped in the explanation of that phenomenon. Studies on marine sediments showed that mercury combinations with humic and fulvic acids are the weakest (Jackson 1998). In the S2SZ soil sample, water content as well as the concentration of total mercury were the highest, however, the re-emission

Fig. 5. Changes in the concentration of total gaseous mercury (TGM) (ng m-3) during subsequent stages of the experiment (simulation of day/night conditions and wind erosion) over soil and waste collected from the landfill in Gdańsk Szadółki in November 2010.



during the third stage (3E) was not the highest - the average concentration of TGM was 50 ng m-3. Thus, none of the discussed parameters characterizing the soil - neither the water content, nor the loss on ignition - could be considered as crucial in the re-emission of Hg into the air. External factors, especially solar radiation, included in the experiments with the soil, could be regarded as important for mercury transformations and release into the atmosphere as an effect of stirring.

The report on monitoring the landfill in Gdańsk - Szadółki showed that in 2009 there were 239328.29 tons of waste deposited. The unsorted municipal waste - which potentially contained the largest amount of mercury - represented a large part of that. In the summer when solar radiation is most intensive, large amounts of waste reach the landfill in Gdańsk. That is due to a large number of tourists visiting the region of Pomerania. During that period, high temperatures and coastal air dynamics would enhance the release of mercury from that soil where large amounts of Hg are deposited. Strong gusts of wind favor the transport of mercury over long distances, even up to several hundred kilometers (Bełdowska and Falkowska 2007, Rogalski and Warmiński 2007). The Gulf of Gdańsk (10 kilometers from the landfill) could be the area of Hg deposition in the summer, especially when SW air flows predominate. Soil in Gdańsk Letnica 1.5 year after the burial ground removal

One and a half year after the burial ground was removed, both in that ground and in the vicinity (LS1, LS2 and LS3), mercury was detected both in trace amounts (5.57 ±0.51 ng g-1) and in higher concentrations (1176.01 ±315.49 ng g-1) (Table 1). In the immediate vicinity of the former burial ground (LS2), the highest concentrations were recorded in the soil (Table 1). Lower concentrations (0.56 µg g-1) occurred in the soil several meters away. The lowest concentrations of mercury were recorded in the most distant point, several dozen meters away from the former burial ground. Thus, the impact of the burial ground, both on the closest and on the distant area, was noticeable. This is probably the consequence of mercury release from the soil and grass into the air during the removal of the burial ground. In addition, gaseous mercury is relatively quickly oxidized in the coastal zone, and through the reactions with sea salts and halides, it can be converted into particles of large

sizes and fall near the place of emission. During the laboratory experiment, the

concentration of TGM over the soil collected in the immediate vicinity of the burial ground (LS2) was 234.6 ng g-1 (Fig. 6). This concentration occurred in the third stage of the experiment (3E), when solar radiation was included and soil temperature increased by about 13°C. Such high concentration of TGM was not measured over any of the samples collected from the landfill in Szadółki or during the removal of the burial ground. That reflected a high potential of mercury emission from the soil. As the high concentrations of total Hg in the soil corresponded to the high concentrations of TGM over the soil, and both the LOI and water content were low (1.21% and 7.10%, respectively), it can be assumed that the

metal was present in compounds easily reducible to the elemental form. This confirms the hypothesis of mercury adsorption on aerosols or reactions with halides, and consequently, the evaporation when the temperature increases. Similar relationships were observed over the LS1 and LS3 soil samples (lower mercury content than in the LS2 sample), where emissions of mercury into the air were proportionally lower. The lowest concentration of Hg was measured in the soil sample (LS3) collected in the area distant from the former burial ground. Unlike the samples LS1 and LS2, the increase in the emission over LS3 was observed already in a dark room when the stirring was included (2E). It could result in the release of mercury bound to organic matter (LOI = 7.49%) when water content was the highest. Solar

Fig. 6. Changes in the concentration of total gaseous mercury (TGM) (ng m-3) during subsequent stages of the experiment (simulation of day/night conditions and wind erosion) over soil collected in Gdańsk Letnica from the area where 20 months earlier the burial ground had been removed (February 2011).


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radiation (3E) could stimulate the photoreduction of the accumulated mercury, similarly to stirring during the fourth stage (4E).

In accordance with the Decree of the Minister of Environment of the 9th September 2002 on soil quality standards and earth quality standards (Journal of Laws No. 165, item 1359), the mercury content in almost all the samples collected from the two study areas exceeded the maximum acceptable concentration in soil (0.5 μg g-1). The presence of organic matter affects the content of Hg, as mercury is bound to it. The emission of mercury to the atmosphere is largely caused by the ability of organic matter to reduce the Hg (II) ions under the influence of solar radiation (Falkowska et al. 2005). Water from the drainage ditch surrounding the burial ground in Gdańsk Letnica

Mercury enters the aquatic environment through the surface runoff or wet and dry deposition. The additional source of mercury to the water surrounding the burial ground was the capillary ascent. Wind mixing caused that the mercury concentrations in water were not as dispersed as in the soil samples. They ranged from 22.00 to 55.00 ng dm-3 (Table 1). Compared to the Baltic water (0.40 - 1.10 ng dm-3) (Murawiec et al. 2007), those concentrations were up to 50 times higher. Also in the coastal region of the Gdańsk Basin, where the surface runoff brings more contaminants, concentrations of mercury were lower - 9.4 ng dm-3

(Saniewska et al. 2010). Even in the rain and snow the concentrations of mercury were lower compared to the drainage ditch, and this refers both to the coastal area of Gdańsk Gulf and central Poland or Silesia (Kluska et al. 2007, Pyta 2009, Siudek 2011).

The results of the experiments conducted on water samples were different from those conducted on soil samples (Fig. 7). The maximum concentrations of mercury in the air over water samples were reported during the fourth stage (solar radiation and turbulent mixing). Under the influence of those two factors, Hg(II) was quickly reduced to Hg(0) and dissolved gaseous mercury (DGM) evaporated into the air. Compared to previous measurements, the highest concentration over the water (D2W1) increased up to 5 times and amounted to 10.6 ng Hg m-3. In the remaining water samples, TGM concentrations did not exceed 5 ng m-3. An increase in the emission of mercury from water was reported also during the second stage of the

experiment, which indicated that mixing accelerated the transformation of mercury to the gaseous form and its release into the air (Bełdowska and Falkowska 2007). Poissant and Casimur (1998) showed the relationship between mercury released from water and the wind speed, r = 0.6244. Only temperature of samples was measured during their experiment with water samples, and the Pearson correlation coefficient was r = 0.5052. Previous studies conducted over the Gdańsk Deep showed the increase in TGM concentrations in the spring, when algal blooms occur and solar radiation is strong (Bełdowska et al. 2008).

The mercury content in the soil of the burial ground was higher than in the surrounding water, however, the distribution of mercury in the ground (due to soil composition) was diversified. This was reflected in the inconsistency of the results and much higher concentrations of TGM during the laboratory experiments (a simulated increase in solar radiation and wind erosion) with the soil than with the water. Those two potential sources (soil and water) of mercury re-emission acted differently under the influence of external conditions. The simulation of external conditions in a laboratory showed that solar radiation is the most important factor increasing the re-emission of mercury from soil. Compared to the initial concentration, TGM concentrations over the soil could significantly increase during intensive radiation and at air temperature above 20°C. The average increase in TGM concentration by 30%, compared to the initial value, was observed over the

Fig. 7. Changes in the concentration of total gaseous mercury (TGM) (ng m-3) during subsequent stages of the experiment (simulation of day/night conditions and wind erosion) over water collected from the drainage ditch surrounding the burial ground in Gdańsk Letnica in July 2009.



soil collected from the area where 1.5 year earlier the burial ground had been removed. The maximum increase in the concentration was about 50%. Only in several cases the increase in TGM concentrations was affected by both factors: solar radiation and mixing/stirring, as it was observed for water samples. SUMMARY

Old waste disposal sites - burial grounds have the potential for re-emission of mercury to the environment, however, they are sources of local importance. Probably, not all burial grounds have been identified so far. The laboratory experiments indicated that re-emission of mercury from the soil of the old burial ground could occur mainly in the summer and daytime - in the periods of intensive solar radiation. On the other hand, the same process but from the water surrounding the burial ground could take place not only in the daytime but also at night. Nevertheless, the re-emission from the water had minor contribution to TGM levels in the air compared with that from the soil of the burial ground. The burial ground served as a mercury repository and its structure provided good protection for the stored waste. Before the process of its removal began, mercury emissions into the air were not registered. Breaking the structure of the burial ground caused the release of mercury and its re-emission into the atmosphere. As the removal proceeded, TGM concentration in the vicinity of the burial ground increased and reached the highest value on the last day when the deepest layers were uncovered. Measurements carried out one and a half year after the removal of the burial ground indicated that the problem of mercury in the air over that place still exists. The soil in the vicinity of the former burial ground was contaminated with mercury, despite the new surface layer. Concentrations of mercury in the samples collected from the modern landfill in Szadółki were similar to those from the old burial ground. This reflects the problem of landfills, in particular the ”illegal dumps”. They become additional, uncontrolled sources of mercury in the air and soil. There are no records of their number and location. They are usually located in forests and directly affect the vegetation.

Mercury content in almost all the collected samples (except those from Szadółki) exceeded the maximum acceptable concentrations in soil (0.5 μg g-1), according to the Decree of the Minister of Environment of the 9th September 2002 on soil

quality standards and earth quality standards (Journal of Laws No. 165, item 1359).

In open areas where landfills are exposed to winds or absorb water from the rainfall, re-emission of mercury from modern landfills would occur to a greater extent. Mercury can be easily transported from the source. The old burial ground as well as the modern landfill should be taken into account as sources of mercury emission to the surface waters of the Gulf of Gdańsk. REFERENCES Bełdowska M., Falkowska L. & Marks R. (2003). Total gaseous

mercury over the coastal zone of the Gulf of Gdańsk. Oceanological and Hydrobiological Studies. 32, 3-18.

Bełdowska M., Falkowska L. & Lewndowska A. (2006a). Airborne trace metals (Hg, Cd, Pb, Zn) of the coastal region, Gulf of Gdańsk. Oceanological and Hydrobiological Studies. 35, 159-169.

Bełdowska M., Falkowska L., Siudek P. & Otręba M., (2006b). Influence of building activities and high-temperature processes on the concentration of gaseousmercury in air. Environment Protection Engineering. 32(3), 31-38.

Bełdowska M., Falkowska L., Siudek P., Gajecka A., Lewandowska A., Rybka A. & Zgrundo A. (2007). Atmospheric Mercury over the coastal zone of the Gulf of Gdańsk. Oceanological and Hydrobiological Studies. Gdańsk. 34, 9-18.

Bełdowska M. & Falkowska L. (2007). Exchange of mercury between air and seawater in day/night cycle, during summer and winter. Oceanological and Hydrobiological Studies. Gdańsk. 34, 51-68.

Bełdowska M., Zawalich K., Falkowska L., Siudek P. & Magulski R. (2008). Total gaseous mercury in the area of southern Baltic and in the coastal zone of the Gulf of Gdansk during spring and autumn. Environment Protection Engineering. Wroclaw. 34(4), 139 – 144.

Biziuk M. (2001). Pestycydy. Występowanie, oznaczanie i unieszkodliwianie. Wyd. Naukowo Techniczne Warszawa.. 229-263.

Carpi A. & Lindberg S.E. (1998). Application of a teflon dynamic flux chamber for quantifying soil mercury flux: Tests and results over background soil. Atmospheric Environment. 32, 873-882.

Ebinghaus R., Turner R.R., Lacerda L. D., Vasiliev O. & Salomons W. (1999). Mercury Contaminated Sites. Characterization, Risk Assessment and Remediation. Springer – Verlag. Berlin Heidelberg New York. ISBN 3-540-63731-1

Falkowska L., Lewandowska A. & Magoński J. (2005). Transfer of chemical substances through the Marine water – atmosphere boundary layer. Archives of Environmental Protection. 31(3),.5-14.

Gworek B.& Rateńska J. (2009). Mercury migration in pattern air- soil- plant. Ochrona Środowiska i Zasobów Naturalnych. Warszawa. 41, 614-623.

Hławiczka S. (2008). Mercury in the atmospheric environment. IPIŚ PAN. Zabrze. 73, 158

Holmes C.D., Jacob D.J. & Yang X., (2006). Global lifetime of elemental mercury against oxidation by atomic bromine in the free troposphere. Geophysical Research Letters. 33, 1 - 5.


www.oandhs.org

DOI:10.1029/2006GL027176. Ignatowicz K. (2008a). Pesticide and heavy metals concentrations

in natural water near graveyard in Podlasie Region. Environmental Engineering, The International Conference May 22-23, Faculty of Environmental Engineering Vilnius Gediminas Technical University. 163-168.

Ignatowicz K. (2008b). Pesticide waste burials in the Area of Podlaskie Provence. Środkowo-Pomorskie Towarzystwo Naukowe Ochrony Środowiska. Koszalin. 10, 545-555.

Jackson T.A., (1998). Mercury in aquatic ekosystem. IN: Metal metabolizm in Aquatic Environment. Chapman & Hall. London. 178-249.

Kabata-Pendias A. (1992). Biogeochemia rtęci w różnych środowiskach. Rtęć w środowisku –problemy ekologiczne i metodyczne. Ossolineum. 7-18.

Kabata-Pendias A. & Pendias H. (1999). Biogeochemia pierwiastków śladowych. Wydawnictwo Naukowe PWN. Warszawa. 2, 170-183.

Kabata-Pendias A. (2011). Trace Elements in soils and Plants. CRC Press Taylor and Francis Group LLC. 520.

Klojzy-Kaczmarek B. & Mazurek J. (2008). Research on Mercury content in selected petroleum deposits of Carpathian region (Poland). Polityka Energetyczna. 11, 211-217.

Klojzy-Kaczmarek B. & Mazurek J. (2010). Mercury In soils fund In the vicinity of selected coal mine waste disposal sites. Polityka Energetyczna. 13, 245-251.

Kluska M., Chrząścik I. & Szymalska M. (2007). Evaluation of Mercury content in water precipitation In the area of City Siedlce by isotachophoresis method. Oceanological and Hydrobiological Studies. Gdańsk. 34, 31-38.

Kopeć M. & Gondek K. (2009). Zawartość rtęci w roślinach górskiego użytku zielonego (Czarny Potok) po 40 latach zróżnicowanego nawożenia mineralnego. Inżynieria Ekologiczna. 21.

Leśniewska E., Szynkowska M.I. & Paryjczak T. (2009). Main Sources of Mercury In Human Organisms not Exposed Professionally. Rocznik Ochrona Środowiska. 11, 403-419.

Magulski R., Falkowska L. & Bełdowska M. (2007). Mercury transformations In the seawater In the presence of Cyclotella meneghiniana and Nodularia spumigena. Oceanological and Hydrobiological Studies. Gdańsk. 34, 69-82.

Marks R. & Bełdowska M. (2001). Air-sea exchange of mercury vapor over the Gulf of Gdansk and southern Baltic Sea. Journal of Marine Systems. 27, 315-324.

Mason R.P., O’Donnell J. & Fitzgerald W.F. (1994). The biogeochemical cycling of mercury in the equatorial Pacific Ocean. Deep-Sea Res. 40, 1897–1924.

Michalska A. (2010). Analysis of mercury content in the environment in the Silesian Voievodeship. Journal of Ecology and Health. 14, 165-168.

Miklavicic V. (1999). Mercury In the Town if Idrija (Slovenia) after 500 years of Mining and Smelting. Environmental Science. Mercury Contaminated Sites. Heidelberg. 259-269.

Murawiec D., Gajecka A., Bełdowska M. & Falkowska L. (2007). Investigation on Mercury concentration levels In coastal and offshore Walters of the Gdańsk Basin. Oceanological and Hydrobiological Studies. Gdańsk. 34, 83-98.

Pacyna E.G., Pacyna J.M., Fudała J., Strzelecka-Jastrząb E., Hławiczka S. & Panasiuk D. (2006). Mercury emission from anthropogenic sources in Europe in 2000 and their scenarios until 2020. Science Total Environment. 370, 147-156.

Poissant L & Casimir A. (1998). Water –air and soil-air Exchange rate of Total gaseous mercury measured AT background sites. Atmospheric Environment. 32, 883-893.

Probst J.L., Messaitfa A., Krempp G. & Behra P. (1999). Fluvial Tranpsorts of Mercury Pollution In the III River Basin (Northeastern France): Portioning Matter and Bottom Sediments. Mercury Contaminated Sites. Heidelberg. 501-520.

Pyta H., Rosik-Dulewska C. & Czaplicka M. (2009). Speciation of Ambient Mercury in the Upper Silesia Region, Poland. Water Air Soil Pollut. 197, 233-240.

Rogalski L. & Warmiński K. (2007). Relationship between anthropogenic emission and wet deposition of mercury in european countries. Oceanological and Hydrobiological Studies. Gdansk. 34, 19-30

Scholtz M.T., Van Heyst B.J. & Schroeder W.H. (2003). Modeling of mercury emissions from background soils. Science of The Total Environment. 304, 195-207

Siudek P. (2011). Mercury in the atmosphere over the urbanized zone of the Gulf of Gdansk. Praca doktorska. Uniwersytet Gdański. Gdańsk

Ustawa z dnia 31 stycznia 1980 r. o ochronie i kształtowaniu środowiska art. 3. pkt. 5a (Dz. U. Nr 49 z 1994r., poz. 196 z późniejszymi zmianami)

Wangberg I., Schmolke S., Schager P., Munthe J., Ebinghaus R. & Iverfeldt A. (2001). Estimates of air-sea exchange of mercury in the Baltic Sea. Atmospheric Environment. 35, 5477-5484.

Wołkowicz W. (2010). Ocena wpływu migracji pestycydów chloroorganicznych z wybranych mogilników, zlokalizowanych w różnych warunkach geologicznych, na zanieczyszczenie osadów i wód podziemnych. Przegląd Geologiczny. Warszawa. 58 (11), 1087-1097

Wołkowicz S. (2003). Rekultywacja terenów zdegradowanych – teoria i praktyka. PIG. Warszawa.

Wołkowicz S., Choromański D. & Wołkowicz W. (2003). Badanie wpływu przeterminowanych środków ochrony roślin (mogilników) na środowisko geologiczne (III etap). PIG. Warszawa. 1-15

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