Scots pine needle surfaces on radial transects across the north boreal area of Finnish Lapland and the Kola Peninsula of Russia

To gain an understanding of the characteristics of the needle surfaces of naturally regenerated Scots pine (Pinus sylvestris L.) and their geographical distribution, eight physicochemical variables were investigated within the north boreal forest area. The visibly undamaged needles were collected in autumn 1990 from 114 plots (3-5 pines per plot) along radial transects from the Monchegorsk and Nikel smelters, emitting SO2 and heavy metals, on the Kola Peninsula, Russia, to Finnish Lapland. The needles were examined by scanning electron microscopy (SEM) and measured for surface wettability using the droplet contact angle (DCA) method. Significant geographical south-north and west-east patterns could be observed in needle surface characteristics, correlating with emissions from the smelters and to climate. Despite the slightly higher initial DCAs (61.4-87.6 degrees) towards the north, the pine needle surfaces of the northernmost transects exhibited higher annual needle wettability change (ANWC) and wax erosion rate (AWER), expressed as the reduction in DCAs and epistomatal wax tube distribution (WTD) during one year, respectively, but a lower occurrence of particles and fungal hyphae than those of more southern transects. The higher ANWC was related to higher atmospheric SO2 concentration, and to the lower long-term temperature sum, but not clearly to annual precipitation. In the Monchegorsk smelter area, the current needles exhibited, on average, a 15% higher WTD and seven degree larger DCA, resulting in more hydrophobic needle surfaces than in Finnish Lapland, but during their first year, both the AWER and ANWC, were greatly increased. In Finnish Lapland, 30%, of all the epistomatal wax tubes disappeared from the needle surface during the first year, the value being 70% for the pines located 8 km from the smelter. The mineral composition of the particles deposited on the needle surfaces mirrored that of the minerals being produced by the smelters (e.g. FexSx, CuFeS2, NixSx, FexOx). Stomatal densities were in the range of 71.1-141.7 stomata mm(-2). The lower densities of stomata on needles close to the smelters correlated with reduced number of needle age classes of the pines, higher dry weights, higher pollutant accumulation and lower Mn and Zn concentrations in the needles. The AWER and ANWC were able to indicate the most seriously deteriorated needle surfaces on a regional scale, e.g. including the surroundings of both smelters, although the plot-specific relationships between 'needle surface variables' and 'pollution variables' were generally weak. The present study showed that the exposure of pine needles to the combined effects of ambient pollutants and harsh climate led to a deterioration in the physicochemical characteristics of the epicuticular wax, which may have serious ecophysiological consequences in the long term.     

Decreased acid deposition and the chemical recovery of Killarney,Ontario, lakes

Lakes in Killarney Park near Sudbury, Ontario, Canada, have shown dramatic water quality changes including general increases in pH and alkalinity, and decreases in SO4(2-), base cations and metals. While some lakes have recovered to pH > 6.0, many are still highly acidic despite decades of improvement. Very high historical S deposition related to emissions from the Sudbury metal smelters dominated the acidification process in this region. However, since the implementation of substantial S emission controls (90%) at the smelters, the Sudbury emissions are no longer the major source of S deposition in the Sudbury area. Wet deposition of SO4(2-) and SO4(2-) concentrations in lakewaters at Killarney now approach values in the Dorset, Ontario, area, about 200 km from Sudbury. This suggests that the S deposition to the Killarney area is now primarily from long-range transport, not from local sources. Studies of Killarney lakes are revealing the complex nature of the chemical recovery process. As lake acidity decreases, other changes including decreased Ca2+ concentrations, increased transparency, and altered thermal regimes may potentially affect some of these ecosystems. It is clear that continuing assessments of the recovery of Killarney lakes, within a multiple-stressor framework, are needed.     

Acidic precipitation in southeastern Arizona: Sulfate,nitrate and trace-metal deposition

Precipitation was collected during 1984 and 1985 at two sites in southeastern Arizona within 100 km of two copper smelters. The precipitation-depth-weighted mean pH was 4.63 and wet sulfate deposition was 8.9 kg ha⁻¹ over a 13-month period. High acidity and sulfate concentration occurred when upper-level winds were from the directions of the smelters. A smelter ‘fingerprint’, based on antimony, arsenic, cadmium, copper, lead and zinc, was identified, and used to evaluate the smelter contribution to precipitation sulfate on an annually-averaged basis. The variations in the relative proportions of these trace metals were too large to permit application of the method to individual precipitation events.     

Trends and sources of particulate matter in the Superstition Wilderness using air trajectory and aerosol cluster analysis

Ambient aerosols adversely affect human health and visibility and impact climate. Identification of sources of particulate matter and its precursors is necessary for developing control strategies. The goal of this research is to utilize long-term speciated particulate matter data and back-trajectory cluster analyses to determine trends and sources of particulate matter in the Superstition Wilderness, a rural area east of Phoenix, Arizona. Twenty-four hour back-trajectories were calculated for every hour of every 24-h particulate matter sample obtained by IMPROVE from 1991 to 2004. Days that included back-trajectories with considerable spatial variance were excluded from further analyses. To minimize uncertainties inherent in single trajectories, all calculated trajectories for each sampling day were averaged to represent the air mass sampled during that day. Cluster analysis of trajectories identified four unique regions, including a region with Phoenix, a region with copper smelters, and one with coal-fired power plants. Yearly averages of sulfate, nitrate, soil, and carbon concentrations were calculated for each region. Statistically significant trends in species concentrations by region and independent of region and differences in concentrations between regions were examined.Sulfate concentrations from the region with smelters were higher than other regions but decreased during the study period. Emissions data from the smelters indicate that much of the sulfate from the region was due to the smelters. The overall 2.2% year⁻¹ decrease in sulfate concentrations at TNM is likely due to decreased emissions from the copper smelters. A 3.6% year⁻¹ increase in nitrate concentrations was driven largely by increasing NO_x concentrations from Phoenix and to a lesser extent the region southwest of the site which includes Tucson and suburban/urban areas between Phoenix and Tucson. Soil concentrations were higher from regions with deserts than the region without desert. This method could not identify trends or source regions of carbonaceous aerosols at this site.     

Sulphur in the Arctic environment (1): results of a catchment-based multi-medium study.

S-concentrations were determined in 9 different sample materials (precipitation (rain and snow), vegetation, O-, E-, B- and C- horizon pf podzols, streams water and ground water) collected in eight small catchments (10-30 km2) at different distances from major SO2 point-source emitters on the Kola Peninsula, Russia. Comparison of the results from these materials, representing different compartments of the ecosystems under varying natural conditions leads to a better understanding of sources, cycling and fate of S in the Arctic environment. More than 300,000 t of SO2 emitted annually from the Kola smelters affect the air quality over a large area. Arctic climatic conditions (cold and dry) and the remote location of the emitters results in considerably lower S-deposition values than those observed in central Europe. The pathways of atmospheric S-deposition in the terrestrial environment vary significantly from summer to winter because different compartments of the ecosystems, with a different capability to accumulate S, are active. The actual S-flux is altered by every component of the ecosystem. When estimating the total S-deposition this effect must be considered.     

Mercury contamination in vicinity of secondary copper smelters in Fuyang, Zhejiang Province, China: Levels and contamination in topsoils

In the present study, we aim to investigate the extent of soil contamination by Hg, particularly by anthropogenic Hg, and tentatively estimate the total Hg (Hg_T) accumulation in topsoils (0-15 cm) in Fuyang, Zhejiang Province—a secondary Cu smelter of China. The results show that the levels of soil Hg in the vicinity of the smelters have been substantially elevated following local smelting activities. The spatial distribution of soil Hg in this area reveals a rapid decrease as the distance from the smelter reaches 1.5 km, which is probably due to the quick deposition process of particulate Hg and reactive gaseous Hg emitted from the smelters. The total accumulation of Hg_T in the topsoils of the study area of 10.9 km² is approximately 365-561 kg and of which 346-543 kg might be contributed by anthropogenic emission alone with an annual emission of 17.3-27.2 kg Hg to the topsoils.     

Geostatistical analysis of soil contamination in the Swiss Jura

The topsoil of a 14.5 km(2) region of the Swiss Jura has been surveyed to identify the distributions of trace metals in it. The soil was sampled at 366 sites selected by combining a square grid and nesting. Concentrations of seven potentially toxic metals, namely Cd, Co, Cr, Cu, Ni, Pb and Zn, were measured. Land use and geology (stratigraphy) were also recorded. Variograms were bounded in the range from 110 m to 1500 m with contributions to the variance at all distances exceeding 6 m. The variograms of Cd, Cr, Cu and Pb are dominated by short range correlation, those of Co and Ni by correlation of long range, and Zn is intermediate. The concentrations were estimated at the nodes of a fine grid by ordinary block kriging and then contoured to produce maps. The maps of Co and Ni have a coarse patchy pattern similar to that of the geology, suggesting that these metals derive from the bedrock. This is supported by analysing the variance by geology. Copper and Pb have finer patterns of distribution, and are more likely to have been added with fertilizer or manure or domestic waste. Cadmium could originate from human activities, such as smelters or fertilizer spreading, or from specific geological deposits, such as moraine.     

Regional dispersion of oxidized sulfur in Central Chile

Chile has a long tradition of exploiting mineral resources, particularly copper (Cu). One of the largest Cu smelters, Caletones, located some 150 km south of the country's capital, Santiago, in Central Chile, is responsible for about 0.4% of about 70 Tg S/yr oxidized sulfur (SO_x) emitted by anthropogenic sources worldwide. Santiago, a megacity with 5 million inhabitants, stands for about 5 Gg S/yr. The average meteorological conditions are unfavorable for the dispersion of pollutants in this area. All this poses risks for human health and vegetation. Also, downwind from these polluted areas there may be large-scale impacts on cloud properties and on oxidative cycles. Here, we present the first attempt to assess the regional distribution of SO_x in Central Chile using a dispersion model (MATCH) driven with data from a limited area weather forecast model (HIRLAM). Emphasis has been given to the impact of Cu smelters upon urban air quality, particularly that of Santiago. Six 1-month long periods were simulated for the years 1997, 1998 and 1999. These periods span over a broad range of typical meteorological conditions in the area including El Niño and La Niña years. Estimates of the regional dispersion and deposition patterns were calculated. The emissions from the large Cu smelters dominate the distribution of SO_x. A budget of SO_x over an area of 200×200 km² around Santiago is presented. There is too low a number of monitoring stations to perform a detailed evaluation of MATCH. Nevertheless, the model reproduces consistently all the regional-scale characteristics that can be derived from the available observations.     

Influence of the turbulence typing scheme upon the cumulative frequency distributions of the calculated relative concentrations for different averaging times

Over a period of three consecutive years (1977–1979) hourly meteorological measurements at the Nuclear Energy Research Centre (SCK/CEN) Mol, Belgium and simultaneous synoptic observations at the nearby military airport of Kleine Brogel, have been compiled as input data for a bi-Gaussian dispersion model. The available information has first of all been used to determine hourly stability classes in ten widely used turbulent diffusion typing schemes. Systematic correlations between different systems were rare. Twelve different combinations of diffusion typing scheme-dispersion parameters were then used for calculating cumulative frequency distributions of 1 h, 8 h, 16 h, 3 d and 26 d average ground-level concentrations at receptors respectively at 500 m, l km, 2 km, 4 km and 8 km from a continuous ground-level release and an elevated release at 100 m height. Major differences were noted as well in the extreme values, the higher percentiles, as in the annual mean concentrations. These differences are almost entirely due to the differences in the numerical values (as a function of distance) of the various sets of dispersion parameters actually in use for impact assessment studies. Dispersion parameter sets giving the lowest normalized ground-level concentration values for groundlevel releases give the highest results for elevated releases and vice versa. While it was illustrated once again that the applicability of a given set of dispersion parameters is restricted due to the specific conditions under which the given set was derived (theoretically, experimentally and/or empirically), it was also concluded that systematic experimental work to validate certain assumptions is urgently needed.     

Climate change impacts on the leaching of a heavy metal contamination in a small lowland catchment

The Keersop catchment (43km(2)) in the south of The Netherlands has been contaminated by the emissions of four zinc ore smelters. The objective of this study was to assess the effects of future projected climate change on the hydrology and the leaching of heavy metals (i.e. Cd and Zn) in the catchment. The numerical, quasi-2D, unsaturated zone Soil Water Atmosphere Plant model was used with 100-year simulated daily time series of precipitation and potential evapotranspiration. The time series are representative of stationary climates for the periods 1961-1990 ("baseline") and 2071-2100 ("future"). The time series of future climate were obtained by downscaling the results of eight regional climate model (RCM) experiments, driven by the SRES A2 emissions scenario, using change factors for a series of climate statistics and applying them to stochastic weather generator models. The time series are characterized by increased precipitation in winter, less precipitation in summer, and higher air temperatures (between 2°C and 5°C) throughout the year. Future climate scenarios project higher evapotranspiration rates, more irrigation, less drainage, lower discharge rates and lower groundwater levels, due to increased evapotranspiration and a slowing down of the groundwater system. As a result, lower concentrations of Cd and Zn in surface water are projected. The reduced leaching of heavy metals, due to drying of the catchment, showed a positive impact on a limited aspect of surface water quality.     

Atmospheric fate and transport of dioxins: local impacts

We conducted model simulations of the atmospheric fate and transport of PCDD/F to assess the fraction of emitted PCDD/F that would deposit within 100 km from the source. We considered eight major categories of PCDD/F emission sources and six different locations, to cover a wide range of source characteristics, PCDD/F congener profiles and particle size distributions, meteorological conditions and terrain configurations. These results suggest that for sources that have tall stacks and/or high plume rise (e.g., copper smelters, cement kilns, sinter plants), only a small fraction of PCDD/F emissions is deposited locally (typically, less than 10% within 100 km). Other source categories such as municipal solid waste incinerators, medical waste incinerators and diesel trucks lead to a greater fraction of PCDD/F being deposited locally; nevertheless, the majority of their PCDD/F emissions tends to be transported beyond 100 km. Although local impacts may need to be addressed for these latter source categories, it appears that the long-range potential impacts of PCDD/F need to be addressed for all source categories. Sensitivity studies were conducted to investigate the effect of various key model inputs on simulation results. These studies suggest that an advanced atmospheric dispersion model should be used for cases where PCDD/F emissions may present some local concerns because the results are very sensitive to the treatment of dispersion. Also, it is essential to obtain accurate characterizations of the particle size distribution of particulate PCDD/F because the dry deposition flux is very sensitive to the particle size distribution.     

Environmental levels of cadmium and lead in the vicinity of a major refuse incinerator

This study examines whether the atmospheric release of Cd and Pb from a refuse incinerator in London has caused contamination of the local environment. Sampling networks were established for street dusts, surface soils, vegetation and total deposit gauges in areas up to 5 km downwind and upwind from the incinerator. Measurements of Cd and Pb indicate there is neither a marked nor an extensive contamination by these metals in the downwind area. However, dust Cd values decreased with distance from the incinerator in this area and Cd deposition rates were higher than in the upwind area. Nevertheless, most Cd values obtained in the downwind area were similar to those previously reported for other parts of London while Pb values were often lower. It is considered that the 100 m stack of the incinerator minimizes the deposition of particulate emissions in the vicinity of this source. Appreciable Cd contamination was found within the grounds of the incinerator, the values being about 4–50-fold higher than in either the upwind or downwind areas. The extent of Pb contamination in this small area was more limited, with values being about twice those found in the two study areas. The source of this contamination is ascribed to fugitive releases arising from the storage and transport of the ashes produced by the incinerator.     

Sulphur in the Arctic environment (3): environmental impact

Long term, high level airborne emissions of pollutants from nickel industries on the Kola Peninsula (NW Russia) have resulted in widespread ecosystem injury up to almost complete vegetation eradication within nearest surroundings of the smelters. Although SO2 is the prevailing component of the emissions, it is only part of a much more complex chemical emission spectrum in the region. In addition to acidic gases, industry also emits potentially toxic elements (e.g. metals) which being less volatile than SO2, are deposited within the immediate region in significant concentrations. Additionally, it appears that sources of base cations (co-emission by smelters, sea aerosols, other industries) are adequate to prevent environmental acidification on the regional scale. Acidification of soils and waters appeared only as single cases in the immediate vicinity of the smelters and is not believed to be a major mechanism of environmental deterioration. Proposed critical concentrations (5 microg/m(3)) of SO2 for the northern ecosystems are exceeded over a large area and direct exposure to SO2 is believed to be the possible mechanism of vegetation damage.     

Investigation of unrecognized former secondary lead smelting sites: confirmation by historical sources and elemental ratios in soil

Twelve suspected former secondary lead smelting sites were investigated. Ten of the sites were confirmed to be former secondary lead smelters or lead works by historical fire insurance maps and contemporaneous metal industry trade directories. At eight sites sampled, the ratio Sb:Pb was closer to ratios from 10 known lead smelting sites than were the As:Pb and Cd:Pb ratios. Data from the 10 known lead smelting sites showed that the Sb:Pb ratio is most characteristic of secondary lead smelting sites. This is because the primary alloy smelted at such sites is antimonial lead. Lead contamination at the eight sites investigated here can be attributed At least in part to the former smelters because of the association between Sb and Pb.     

Relations between Scots pine needle element concentrations and decreased needle longevity along pollution gradients

Scots pine (Pinus sylvestris L.) shoots were sampled along transects near one urban pollution source and two smelters. Needle Mg, P and K concentrations decreased from the second to the fourth age class linearly with needle survival along the urban pollution gradient. Still, over 80% of the average concentration of these nutrients remained in the fourth needle age class. Decreased needle longevity was closely related to the increased heavy metal concentrations near the smelters. Near the urban pollution source, it was related to the increased annual needle mass and the increased needle nutrient concentrations. Decreased Mn accumulation along with needle age was detected near all pollution sources. Leaching of Mn from needles and especially from soil as a cause of decreased needle concentrations is discussed.     

Informative Report

Abstract

Chemical composition and particle size data for particulate emissions from stationary sources are required for environmental health effect assessments, air chemistry studies and for air quality modeling investigations such as source apportionment. The Information presented In this paper is directed to those individuals concerned with these environmental Investigations. In this study, particulate emissions from a group of non-ferrous smelters have been physically and chemically characterized. Emission samples were collected at the baghouse outlets from smelter furnaces and at smelter acid plant stacks at three locations; a zinc, a lead, and a copper smelter.

Mass emission rate determinations were made by EPA reference methods. Cascade impactors were used to collect in-stack samples for particle size distribution measurements. Particulate samples for chemical characterization were collected on membrane filters for analysis by X-ray fluorescence spectroscopy. Development of measurement techniques required to determine the elemental composition of the total mass and sized fractions of the emission are discussed. Results of the tests at the three smelters include total mass and elemental emission rates, particle size distribution, and the elemental composition of the total particulate mass and of sized fractions from both the smelter furnaces and acid plants. The results obtained at the copper smelter may not be representative of the emissions at the many copper smelters where reverbatory furnaces have been replaced.     

Topsoil (0-5 cm) composition in eight arctic catchments in northern Europe (Finland, Norway and Russia)

Frozen topsoil samples (0-5 cm) were collected during March/April 1994 in eight Arctic catchments in northern Europe (four in Russia, three in Finland, one in Norway), at different distances and in different wind directions from the emissions of the Russian mining, roasting and smelting industry on the Kola Peninsula. Between 14 and 25 sites were sampled in each of the eight catchments ranging in size from 12 to 35 km2. Results show that close to the smelters in Monchegorsk and Nikel, topsoil is clearly enriched in Ag, As, Bi, Cd, Co, Cr, Cu, Fe, Ni, Pb, Sb, Se, Te and V. Cu and Ni median contents in topsoils collected close to Monchegorsk are about 600 times higher than in the Finnish catchments. The effect of open-cast mining and waste dumps of alkaline rocks from the nephelinite industry near Kirovsk can be seen in the elevated contents of Al, Ba, K, La, Mn, Na, Sr, Ti, Y and Zn in topsoil collected in a nearby catchment. For many elements, however, variations observed in single catchments are as great as the total regional variation. Several elements (e.g. Cd, Hg, Cu, Ni, Pb, S, Zn) show strong positive correlation between the organic content of the sample and the element content observed. Thus it is necessary to determine the organic content of the samples and correct the element levels when using depth-related soil samples (here, the 0-5 cm topsoil layer) for regional mapping.     

Tracing the influence of sewage nitrogen in a coastal ecosystem using stable nitrogen isotopes

This paper reviews the use of stable nitrogen isotopes (delta15N) to delineate the influence of sewage nitrogen (N) in coastal ecosystems, drawing extensively on the case of Himmerfj?rden, a Baltic Sea bay that receives 15N-enriched tertiary treated sewage that is discharged mainly as dissolved inorganic N (DIN). Gradients of delta15N in macroalgae (Fucus vesiculosus) and surface sediments traced sewage-derived N to 24 km from the outfall but elevated delta15N values (> 7 per thousand) indicated that the sewage influence was most pronounced within 10 km. Comparison of macroalgal delta15N values before and after enhanced tertiary treatment showed a decrease in the spatial impact of sewage N from about 24 km to 12 km from the outfall and a decrease to more marine delta15N values in more recent growth tissues. Sedimentary delta15N records showed that sewage has had a dominant influence on organic matter production in the bay with dramatic increases in sedimentary delta15N during the years of maximum sewage N loads. In cases where sewage N introduces a distinct isotopic signature into a system and where it has had a dominant influence on organic matter production, delta15N values in biota and sediments can be used to trace the spatial and temporal influence of sewage N in aquatic ecosystems.     

Anthropogenic and natural levels of arsenic in PM10 in Central and Northern Chile

A few copper and gold smelters in Chile are behind a large fraction of global arsenic emissions, raising concerns for increased concentrations of arsenic in PM10 in Central and Northern Chile. This concern is amplified by the fact that Northern Chile soils and rivers in general are characterized by a high arsenic content. A monitoring and modeling study has been performed to quantify the regional impact of the smelter emissions. Measured atmospheric arsenic concentrations from 2.4 to 30.7 ng m⁻³ were found at seven rural stations, located tens to hundreds of kilometers away from the nearest smelter. Analyses of topsoil and subsoil samples taken from PM10 monitoring stations revealed levels up to 291 mg kg⁻¹, the highest values found in the northern Atacama desert in Chile. An absolute principal component analysis of selected trace elements in PM10 shows that the regional impact of anthropogenic smelter emissions on airborne arsenic concentrations is more important than the effect of soil dust resuspension. The dominance of the smelter emissions is larger in Central Chile than in the northern parts. The impact of resuspended soil dust on airborne arsenic levels in rural areas was estimated not to exceed 5 ng m⁻³. The model calculations support the dominant role of anthropogenic emissions and give spatial and temporal variations in atmospheric concentrations consistent with the monitored levels at five of the seven stations. At two of the northernmost stations indications were found of unidentified sources other than the smelters and the resuspended soil dust, contributing to about 5 ng m⁻³ of total arsenic levels. The study confirms that a strong control or elimination of arsenic emissions from the smelters would lead to arsenic in PM10 levels in Northern and Central Chile comparable to non-polluted areas in other countries.     

Fingerprints of dioxin from thermal industrial processes

PCDD/F homologue profiles and 2,3,7,8 chlorine-substituted congener patterns are studied using principal component analysis and hierarchical cluster analysis. Measurement data from different industrial metallurgical processes such as iron and steel manufacturing, copper smelters and aluminium plants are compared. It appears that the PCDD/F homologue profiles from industrial metallurgical processes are similar to those from municipal solid waste incinerators. The 2,3,7,8 chlorine-substituted congener pattern from copper smelters is also very similar to that of municipal solid waste incinerators. However, the 2,3,7,8 chlorine-substituted congener pattern from an aluminum plant is very different, 2,3,7,8-TCDF being by far the most important TCDF congener.