Elemental and Base Anions Deposition in the Snow Cover of North-Eastern Estonia

Snow samples from 18 sites in Estonia were collected in February and March 1996 after 72–110 days of permanent snow cover. Three snow layers corresponding to different snow accumulation periods were separated in each sampling site. Snow water samples were analysed for sulphate (SO₄ ^2-), nitrate (NO₃ ^-), and chloride (Cl^-) ions and elemental composition. Deposition fluxes of 27 chemical species were used for factor, cluster and correlation analysis. The effects of cement dust, oil shale fly ash, sulphur dioxide and chlorine from emissions of thermal power plants were distinguished. A large number of trace metals are strongly correlated with each other (R > 0.8) and with macro-components (except NO₃ ^-), which refers to a common origin, identified as the mineral part of oil shale. Deposition fluxes of Ca, Mg, SO₄ ^2- and a number of mineral components exceed near the power plants 1–2 decimal orders the background value. The deposition fluxes in forested sites are up to 2 times higher than in open land sites. This difference may be caused by more efficient turbulent transfer over rougher surface. It is suggested, that NO₃ ^- and Zn originate mainly and Pb, Cd and Cu partially from non-local or diffuse sources (traffic, domestic heating, far transport). The results of this research could be used to evaluate the air pollution deposition models and for ecological impact estimations.     

Modelling sulphur dioxide levels in the Sarnia area

For environmental planning and policy-making purposes, this study was undertaken to apply the Ontario Ministry of the Environment Air Quality Model for SO₂ to an urban-industrial region, namely, the Sarnia and St. Clair River area. Predicted and measured SO₂ levels showed good agreement. A comparison of daily model predictions with 118 observations from 11 monitoring stations for 12 days in 1973 gave an overall correlation coefficient of 0.88.     

Air Pollution Effects on Terrestrial Ecosystems in Estonia

A number of positive changes have taken place since Estonia regained its independence in 1991. Air pollution from stationary sources has decreased over 2.5 times during 1990–1999, emissions of solid particles and SO₂ have declined 74% and 60%, respectively. The content of heavy metals in Estonian mosses has decreased in comparison with the early 1990s. Last five years occurrence of different kind of damages on decidious trees has not been frequent. Those facts indicate that air pollution with heavy metals and other pollutants has diminished during the last few years. As the pH of precipitation fluctuates in different parts of Estonia, it is very important to study the effect of precipitation on ecosystems on the basis of critical loads. Results indicate that, as for eutrophicating nitrogen, the actual nitrogen deposition in North-East Estonia and West-Estonian islands roughly coincides with the limits for pollution endurance. This pattern also applies to the total deposition of sulphur and nitrogen in South, North and North-East Estonia, although in some Northern and North-Eastern areas pollution endurance limits have been exceeded.     

Effect of sulphur dioxide on precipitation and on the sulphur content and acidity of soils in Alberta,Canada

Rain and snow in Alberta are seldom acid. The S content of snow is so low that the snow pack gives a deposition of less than 1 kg S ha^?1, even downwind from large SO₂ emission sources. Rainfall contributes at the most 4 kg S ha^?1 yearly near SO₂ sources, and only about 1 kg S ha^?1 in clean areas. However, rain intercepted by forest trees exposed to SO₂ emission becomes acid (pH 3.5 to 4.5) and has a S content of 3 to 4 times greater than rain. Soils absorb large amounts of S from emissions (up to 50 kg S ha ^?1 annually) but much of the S is found in non-sulphate form. Soils are slowly acidified by the SO₂ at a rate estimated at 1 pH unit in 10 to 20 yr. Water surfaces will absorb SO₂ emissions at a rate of about 4 to 15 kg S ha^?1 annually. Particulates deposit 3 to 4 times as much S as is deposited by rainfall.     

Trends in sulphur dioxide concentrations and sulphur deposition in the urban atmosphere of Rijeka (Croatia), 1984–1993

Trends in sulphur dioxide (SO₂) annual mean concentrations in the period 1984–1993 are given for two sites within the city of Rijeka. During this period a decline (in average 30%) is observed since mid-eighties up to now at both sites. Dry deposition of sulphur as sulphur dioxide (S-SO₂) follows the same trend. Deposition of total sulphur as sulphates (S-SO₄) and wet S-SO₄ exhibit similar pattern with a decline of 45%. Rain scavenging is found to be the main path of sulphate removal from the atmosphere. The decline of sulphur compounds in the urban atmosphere of Rijeka can be attributed to the use of fuel with lower sulphur content.     

The effect of sulphur dioxide on extractable manganese in soils

Abstract

The treatment of soil with SO₂ caused rapid increases in concentrations of water soluble plus exchangeable (extractable) Mn. The extractable Mn increased with increasing pressure of SO₂ and time of exposure, and increased with increasing water contents up to field capacity but decreased beyond this point. The addition of peat to a sandy loam increased the effect of SO₂ on extractable Mn while the addition of lime decreased the effect. Reactive Mn oxides in soils may contribute significantly to SO₂ sorption by soils.     

Deposition of sulphur gases from multiple scattered sources in Alberta

Various measurements utilizing soils, plants, precipitation and free water surfaces indicate that approximately 7 to 9 kg ha^?1 of sulphate S was deposited annually within an area of 4600 km². This area contained or had adjacent to its boundaries 10 S emission sources for which the provincial government had established a combined allowable daily emission of approximately 330 tonne S. At distances of 40 or more km from the emission sources the annual deposition rate had declined to4 to 6 kg ha^?1.     

Soil organic matter fractions as sources of plant-available sulphur

Pot culture experiments are described which attempt to identify the organic fractions of soil sulphur that decompose during the growing season to provide plant-available sulphur.Soil organic matter was labelled with ³⁵S by incubating soil with labelled sulphate and several organic sulphur fractions were determined before and after the growth of Sorghum vulgare and following a fallow treatment. The effect of moisture stress on the uptake of sulphur by plants was also investigated; this treatment had little effect.Changes occurred in both hydriodic acid-reducible and carbon-bonded sulphur fractions, 60 per cent of the sulphur taken up by the plants being derived from the latter. The changes in carbon-bonded sulphur involved changes in both Raney nickel-reducible and non-reducible sulphur fractions. All of the sulphur fractions investigated thus contributed available sulphur for plant uptake, and none of them are likely to be of any value for predicting the sulphur requirements of plants.     

Removal of sulphur dioxide and sulphates from the atmospheric surface layer during frost formation

In order to establish the amount of removal of SO₂ and sulphates from the lowest layer of the atmosphere during frost formation, a field measurement experiment was conducted in January 1990 in the Ravenna area. Frost can bring about removal of particles, gases and hydrosoluble substances. In common with areas of the Po Valley, Ravenna is frequently subjected to atmospheric conditions that can cause frost. During the winter of 1990, clear skies at night, that were associated with high pressure fields, strongly influenced the formation of frost. Close to industrial plants, characterized by wet emission of plumes, this frost has an adverse impact on soil, commonly known as ‘chemical snow’. A large number of frost samples, collected in three locations representing typical but different features of the area (rural, urban and sea front sites), were analyzed. Analysis of the data reveals that SO₂ is the major contributor SO₄ ^?? trapped in frost.     

Leaf litter decomposition and soil microarthropods affected by sulphur dioxide fallout

A field experiment was set up in northeastern Italy to investigate the effects of sulphur dioxide fallout on leaf litter decomposition rates and soil microarthropods. The pollution fallout, which affected part of the Po River delta, originated from the activity of an oil-fired power plant located at Isola Camerini (Porto Tolle, Rovigo). Four sampling sites, exposed to different amounts of pollutant fallout, were selected along the river bank. Two sites, located 1·5 km from the power-plant stack, received minimum sulphur dioxide fallout and were used as controls; two high-deposition sites were about 13 km away from the power-plant settlement. Soil cores were taken to compare sulphur concentrations in the upper layers of the sampling site soil profiles. Litter bags filled with plant material of various types, laid down over two consecutive sampling periods, were used to study leaf litter decomposition and sulphur accumulation on plant tissues. Microarthropods were extracted from the litter bags by means of a modified Tullgren apparatus. Soil chemical analysis showed the highest sulphur concentrations at the high pollutant deposition sites along the plume path. Litter bag dry weight loss over time was reduced by sulphur accumulation in plant tissues. Sulphur accumulation in litter bags gave an indirect measure of the differential pollutant deposition over the land. High-deposition sampling sites showed a significant reduction in the total number of some decomposers. Collembola, in particular, appeared to be a robust bio-indicator of pollutant fallout. Conclusions were drawn about the possible detrimental effects of sulphur compounds on soil and leaf chemistry, litter decomposition and microarthropod decomposer populations.© 1997 John Wiley & Sons, Ltd.     

Chemical changes in decomposing forest litter in response to atmospheric sulphur dioxide

Decomposing needle and leaf litter, from a pine (Pinus sylvestris L.) stand and a mixed deciduous woodland, respectively, were exposed to arithmetic mean SO, concentrations of up to 50 nl l^?3 (mm³ m^?3) in controlled field-based experiments lasting up to 215 d. The objectives of the study were: (1) to evaluate whether SO, concentrations, known to occur in parts of Europe, could alter the chemical composition of forest litter and leachates, and (2) to use such information to complement results obtained during microbiological studies (Wookey et al., 1991). Dry deposition of SO, on the litter resulted in the production of sulphate during damp conditions or when the litter was moist. The formation of SO^2?₄ and associated H+ ions led to cation exchange processes whereby Mg²⁺ and Ca²⁺ in particular were leached from the litter. This resulted in significant (P<0.01) depletion of magnesium and calcium in both litter types, even at the lowest SO₂ concentrations tested (15 nl l^?1). Incomplete buffering by base cations resulted in acidification of leachates. The magnitude of cation leaching and depletion within the litter was not always linearly related to SO, or leachate SO^2?₄ concentrations, and the role of microbial processes and litter quality as modifiers of such responses is considered.     

Nitrogen and sulphur management: challenges for organic sources in temperate agricultural systems

Abstract. A current global trend towards intensification or specialization of agricultural enterprises has been accompanied by increasing public awareness of associated environmental consequences. Air and water pollution from losses of nutrients, such as nitrogen (N) and sulphur (S), are a major concern. Governments have initiated extensive regulatory frameworks, including various land use policies, in an attempt to control or reduce the losses. This paper presents an overview of critical input and loss processes affecting N and S for temperate climates, and provides some background to the discussion in subsequent papers evaluating specific farming systems. Management effects on potential gaseous and leaching losses, the lack of synchrony between supply of nutrients and plant demand, and options for optimizing the efficiency of N and S use are reviewed. Integration of inorganic and organic fertilizer inputs and the equitable re-distribution of nutrients from manure are discussed. The paper concludes by highlighting a need for innovative research that is also targeted to practical approaches for reducing N and S losses, and improving the overall synchrony between supply and demand.     

Radial Growth Response of Scots Pine to Climate under Dust Pollution in Northeast Estonia

Dendrochronological techniques were used to investigate the influence of climatic factors on the radialgrowth of Scots pine (Pinus sylvestris L.) under theimpact of dust pollution in the industrial region of NortheastEstonia. Study sites Narva-1 and Narva-2 suffer dust pollutionstress from oil shale fired power plants located in thisregion. The impact of climate on radial growth of pines atthree study sites was modelled using response functionanalysis. Tree-ring indices chronologies for each study sitewere compared using regionally averaged temperature andprecipitation data sets for the period 1946–1991. Amongtemperature variables significant predictors of radial growthalong with the temperature of winter months, generallylimiting the growth of pines in this region, are midsummertemperatures of the current year and temperatures of theprevious growth season. For each site a different set ofprecipitation variables limiting growth was detected. Only anoptimum amount of precipitation during the previous summer hasa positive effect on radial growth on all sites. An increasedimportance of precipitation to the radial growth in dust-polluted sites was detected.     

Sulphur and nitrogen nutrition and misting effects on the response of bluegrass to ozone,sulphur dioxide,nitrogen dioxide or their mixture

Kentucky bluegrass (Poa pratensis L.) plants, cultivars Cheri, Merion and Touchdown were grown at complete nutrition or with low S or low N. Plants were exposed to 10 ppm (v/v) O₃ for 6 h d^?i, 15 pphm SO₂ continuously, 15 pphm NO₂ continuously, or their mixture at these concentrations for 10 days. The severity of injury was much increased by misting with deionized water for 5 min twice daily, especially with SO₂ and NO₂ single gas exposures. The misting did not have consistent effects on total S, total N, leaf area or fresh weight. Exposure to O₃ decreased leaf area without affecting S or N content, while SO₂ usually increased total S and, in some cases, increased total N. Exposure to NO₂ increased total N without affecting total S, and the mixture increased both total S and total N. Low S or low N usually enhanced the effect of SO₂ or NO₂, respectively. Leaf area and fresh weight were not as responsive to the treatments as total S and total N. Rainfall outdoors may be a major meteorological factor affecting plant injury response to gaseous pollutants.     

Temporal Changes in the State of a Pine Stand in a Bog Affected by Air Pollution in Northeast Estonia

We used the needle trace method to investigate changes in the state of a Scots pine (Pinus sylvestris L.) stand in a bog (Voorepera) in the north-eastern part of Estonia, the most polluted area of the country. Additionally, we chose six sampling sites in other parts of Northeast Estonia (polluted area) and eight sites in southern Estonia (unpolluted area) to compare the state of pine stands in different bogs. During the period of 1964–1997, the radial growth had increased from 0.27 to 2.16 mm yr^–1 and the annual shoot length from 0.10 to 0.28 m in Voorepera. Mean values of the period (1.13 mm yr^–1 and 0.26 m, respectively) were two and four times higher in Voorepera than the average of the other bogs (0.5 mm yr^–1 and 0.06 m, respectively). Maximum needle age fluctuated between three and five growing seasons in Voorepera, the mean (four growing seasons) was similar to that of other bogs (four growing seasons). Except radial growth, which was 0.6 mm yr^–1 in the polluted area and 0.4 mm yr^–1 in the unpolluted area, other indices of trees' health (shoot growth, needle age, nitrogen concentration in needles) and substrate conditions (water pH and N concentration) did not show clear differences between polluted and unpolluted areas. We conclude that air pollution from oil shale industry (thermal power plant and chemical factories) enhances the growth of pines in bogs, which can induce drastic changes in these ecosystems. However, the effect is currently obvious only in the vicinity of pollution sources.     

Atmospheric sulphur dioxide and rainwater at a coastal locality in N.W. England

The relationship between atmospheric SO₂ concentrations and rainwater pH is examined for a coastal locality in North Merseyside, England for the period 1978 to 1982. During this period rainwater pH has risen slightly but significantly while atmospheric SO₂ levels have fallen. The relationship between SO₂ levels, rainwater pH and wind frequency and wind run from eight sectors of the compass are analyzed. Higher SO₂ concentrations coincide with southerly, southeasterly and easterly winds from urban and industrial source areas. Slightly higher frequency and run of wind occur from the south and east during the winter season when SO₂ production is increased.     

Specifics and Temporal Changes in Air Pollution in Areas Affected by Emissions from Oil Shale Industry, Estonia

Atmospheric air pollution levels and long-term effects on the environment caused by simultaneous presence of SO₂ and oil shale alkaline fly ash during the last five decades (since 1950) were investigated. The annual critical value of SO₂ for forest (20 µg m^?3) was surpassed in 1% (～35 km²) of the study area where the load was 30–40 µg m^?3. No effect of long-term SO₂ concentrations of up to 10–11 µg m^?3 (0.5-h max up to 270 µg m^?3) and simultaneous fly ash loads of up to 95 µg m^?3 (1000 µg m^?3) on the growth and needle longevity of Pinus sylvestris was established. The yearly deposition (average load up to 20–100 kg S ha^?1) was alkaline rather than acidic due to an elevated base cation deposition in 1960–1989. Since 1990, the proportion of SO₂ in the balance of components increased: about 70–85% of the total area was affected while the ratio of annual average concentrations of SO₂ to fly ash was over 1. The limit values of fly ash for Sphagnum mosses and conifers in the presence of SO₂ are recommended.     

Sulphate sulphur concentration in vegetable crops,soil and ground water in the region affected by the sulphur dioxide emission from Płock oil refinery (central Poland)

Research was carried out in 1984–1990 in the region affected by the sulphur dioxide emission from one of the greatest oil refineries in Europe (P?ock, central Poland). The sulphate sulphur concentration in the vegetable crops (red beet, carrot, parsley, bean, cabbage and dill), the soil and in ground water was defined in selected allotment gardens of P?ock city and in a household garden located in the rural area about 25 km from the town. The highest amount of sulphate sulphur was found in the vegetable crops cultivated in the garden situated in the closest vicinity of the refinery. Sulphate sulphur contents harmful for plants (above 0.50 per cent d.m.) were noted in cabbage and carrot leaves in almost all the gardens (except one). The soil in all examined gardens was characterised by high sulphate sulphur concentration, which considerably exceeds the maximum amount admissible for light soils in Poland, i.e. 0.004 per cent Am. The sulphate sulphur concentration in ground water in all the gardens exceeded the highest permissible content in drinking water in Poland (200 mg^*dm^?3 of sulphate or about 67 mg^*dm^?3 of sulphate sulphur). The sulphate sulphur content in the soil and ground water was not significantly dependent on the garden's distance from the refinery. Generally, the abovenormal sulphate sulphur concentrations occurred quite universally in the examined region and they concerned all the considered environmental components (vegetable crops, soil, ground water) and all the gardens.