Atmosperic deposition of mercury in Norway: temporal and spatial trends

Data from a study of Hg in the terrestrial environment in Norway are presented. Analyses of moss samples and comparison with wet deposition data indicate that dry deposition of gaseous Hg is important at northern latitudes. The Hg content of the humus layer of natural soils shows only moderate regional differences, but is to some extent dependent on atmospheric deposition from long-range transport and local point sources. Peat cores from ombrotrophic bogs provide information about recent and pre-industrial levels of Hg deposition, the ratio between levels varying from less than 2 to almost 10 depending on the location. Surprisingly high levels in surface peat in the northern part of the country support the conclusion indicated from moss analysis concerning the significance of dry deposition.     

Atmospheric deposition in Fenno-Scandia: Characteristics and trends

Chemical analyses of daily precipitation samples from “background” stations in Europe are discussed together with measurements of airborne SO₂ and sulphate aerosol, and trends in energy usage and SO₂ emissions. Emission sources contributing to the major part of the concentrations of sulphate and nitrate in precipitation are mostly 500 to 1000 km from the receptor area. Although there are no general statistically significant trends in the precipitation chemistry data, minor changes point to an effect of reduced S02 emissions in some areas. The daily data can be used to infer general conclusions with respect to precipitation scavenging efficiency.     

Sulphur and nitrogen deposition in Norway,status and trends

The total deposition of sulphur (S) and nitrogen (N) components in Norway during the period 1988–1992 has been estimated on the basis of measurement data of air- and precipitation chemistry from the national monitoring network. There are large regional variations in depositions with highest values in the southwestern part of Norway. Time series analysis of annual mean concentrations of sulphur dioxide (SO₂) and sulphate (SO₄ ^––) in air, non marine SO₄ ^––, nitrate (NO₃ ^–) and ammonium (NH₄ ⁺) in precipitation, shows a significant reduction in the S concentrations both in air and precipitation. In precipitation the concentrations are reduced by 30–45 percent in Southern Norway and 45–55 percent in Central and Northern Norway. Even larger reductions are observed in air concentrations with 50–65 percent reduction in Southern Norway and 65–88 percent reduction further north. For N components there are generally no significant trends in concentration levels nor in precipitation or air. The observed trends are comparable with reported trends in emission.     

Atmospheric deposition to remote receptors II. Temporal and spatial variation of inorganic ion species in precipitation over the Ilwas-network

Water, Air, & Soil Pollution - Measurements of SO4 −, NO3 −, Cl−, NH4 +, Ca++, Mg++ Na+, K+, pH, and specific conductance, were made on a precipitation event basis (defined as...     

Factor analysis of atmospheric trace-element deposition data in the netherlands obtained by moss monitoring

Monte Carlo-Assisted Factor Analysis has been applied to a data set of trace element concentrations in samples of the moss species Pleurozium schreberi, collected in 1992 from 66 locations in the Netherlands. A Monte Carlo approach was used to give more insight in the uncertainties and significance levels of the factor analysis results. Using a selection of 23 elements, factor analysis enabled the identification of 8 significant pollution source types. Two source types were assumed to be related to the influence of foliar leaching from higher plants. The remaining source types were found to correspond with the major source types obtained in earlier biomonitoring surveys in the Netherlands using lichen and bark, i.e. crustal material, sea aerosol and various types of industrial pollution sources, associated with metallurgical industries, refuse incineration and oil combustion or processing of oil products. The contribution of the industrial pollution sources appeared to have decreased between 1987 and 1992.     

historical deposition rates of Cd,Cu, Pb,and Zn in Norway and Sweden estimated by 210Pb dating and measurement of trace elements in cores of peat bogs

From six ombrotrophic mires located far from distinct local sources in Sweden and Norway, a core was sampled in bog hummocks in 1988 and dated by 210_Pb. Ten slices from each core were analyzed for Cd, Cu, Pb, and Zn. Based on the datings, the accumulation rates of Cd, Cu, Pb, and Zn have been estimated for the last 150 years. A reasonable agreement exists in the comparison between the recent deposition in the peat bog and nearby bulk deposition measurements. Highest deposition has been measured in southern Norway and the western part of Sweden. Generally, deposition has increased during the last 150 years, except at a station on the east coast of Sweden. In a study in Sweden where heavy metals have been measured in mosses every five years time since 1970, significant decreases in the concentrations of heavy metals have been found. Similar decreases have not been measured in the present study, although both methods are expected to reflect atmospheric deposition. Several studies have indicated that peat bogs are not suitable for measuring the historical evolution of trace metals. However, despite the disagreement, the recent literature suggests that it can be done with reasonable accuracy when performed with samples from hummocks in the peat bog.     

Atmospheric mercury and trace elements in the region of Alta Floresta in the Amazon Basin

In the early 1980's the Amazon region in the North of Brazil was the scene of the most intense gold rush in the history of Brazil. Metallic mercury (Hg) in gold mining activities is used to amalgamate particulate gold. The other sources of Hg emissions in Amazonian are tailing deposits and biomass burning of tropical forests and savannas. Total Hg concentrations in the urban area of Alta Floresta ranged from 20 to 5800 ng/m³. Indoor total Hg concentration in gold shops ranged from 250 to 40600 ng/m³. Particulate Hg accounts for 5 to 20% of total Hg in Alta Floresta. Through Factor and cluster analysis it was obtained a pattern of relationships between total Hg, fine and coarse mode particulate Hg, Pt, Pb, Ag and several other trace elements associated with the amalgamation process. A clear correlation was also observed with the fine mode biomass burning aerosol and coarse mode soil dust.     

Temporal and spatial trends in metal loads to sediments of Lake Simcoe,Ontario

Metal loads to sediments of Lake Simcoe were partitioned into three components, which were attributable to natural background, accelerated erosion, and point + atmospheric sources. These loads were calculated over time using metal concentration profiles together with pre-settlement sedimentation rates based on sonar and time-variable sedimentation rates based on ²¹⁰Po profiles in cores. Concentrations of metals significantly higher than pre-settlement concentrations were observed in all cores in the case of Pb, back to 80 yr BP on average, and in at least 75% of cores, back to 60 yr BP for Cd and Zn and 30 to 45 yr BP for Cu, Ni, and Cr. Total metal loads increased 3 × for Cu and Ni, 4 × for Zn and Cr, 11 × for Cd and nearly 20 × for Ph from pre-1800 to 0 to 10 yr BP. At present about 90% of the anthropogenic loads of Pb and Cd, and 60 to 70% of the anthropogenic Cu, Ni, Zn, and Cr, are from point + atmospheric sources, the balance being from increased erosion. The direct atmospheric input of Cd is relatively high, approximately 77% of point + atmospheric inputs, while inputs of Cr and Ni are low at 1% and 9%, and inputs of Cu, Zn, and Pb are intermediate at 20 to 40% of point + atmospheric inputs. Two significant findings on spatial distribution of metals were the large increases in metal loads to Cook Bay following the drainage of 33 km² of marshes for agricultural use and the widespread dispersal of Cr from point source(s) in Kempenfelt Bay.     

Principal component analysis of trace elements in Serbian wheat

Trace elements (Cu, Fe, Pb, Hg, Cd, As, Mn, Zn) were analyzed quantitatively in 14 wheat samples collected from fields in all Serbian growing regions, harvested in 2002. Microelements were determined according to an atomic absorption spectrophotometric method. Principal component analyses (PCA) were performed on data matrices consisting of contents of trace elements in wheats (columns) and all Serbian wheat-growing regions (rows). It was found that four principal components account for 87.2% of the total variance in the data. The plot of component loadings showed significant groupings for concentration of some microelements. The component scores indicated the similarities among the Serbian wheat-growing regions. The loading plot reveals that there is no need to measure all of the variables to achieve the same classification. It is enough to measure one variable per group. Naturally, this conclusion is valid only within the limits of the present study of wheat grain samples from different parts of Serbia.     

The effect of pH and atmospheric deposition on concentrations of trace elements in acidified freshwaters: A statistical approach

A statistical evaluation of 5 338 analysis of freshwaters from little polluted stream basins in the Czech Republic indicated a relationship between the Pb, Cu, Zn, Cd, Be, As, Mn, Sr, F^? and Fe concentrations and the pH, over a range of pH 3.6 to 9.6. Except for Sr, the median concentrations of all the trace metals increase with decreasing pH, but the increase never extends over the whole studied acidic range (pH 3.6 to 7.0). Acid deposition related mobilization of Mn and Be into freshwaters explains the sharp increase in their concentrations with decreasing pH. Cadmium and Zn are also mobilized n strongly acidic environment. The concentrations of Be, As, F^? and Mn in strongly acidic waters and those of Zn and Cd in weakly acidic ones are considerably higher in areas receiving a higher atmospheric loading. For Be and Mn, the higher concentrations are caused by higher acid deposition rates, while for As and F^?, the concentrations are probably greater due to higher atmospheric deposition of these elements over more intensely acontaminated areas of the Czech Republic. In extremely acidic waters (pH < 4.2), the concentrations of Mn, Be, Cd, Zn and Al no longer increase with decreasing pH; on the contrary, those of Mn and Be actually decrease. This seems to be primarily caused by a decrease in their concentrations within the surface horizons of soils and vegetation induced by prolonged leaching. The Cd and Zn concentrations are independent of pH over an interval of pH 5.4 to 6.0 and thus the increase in the mean concentrations of Cd and Zn with decreasing pH involves two separate stages, at pH > 6.0 and at pH < 5.4. The concentrations of Cu in acid freshwaters are controlled by both the presence of high molecular weight organics plus biota uptake and by their atmospheric deposition levels; the concentrations of As and Pb are in addition controlled by sorption on Fe - oxyhydroxides. These elements accumulate in the topsoil, even under conditions of severe acidification. The surprisingly lower concentrations of Pb and Cu were found in acidic waters of more contaminated areas.     

Acidification in Norway — Status and trends

Surface and ground water monitoring in Norway is designed to give a regional coverage with most of the stations in areas with acidification and some stations in unpolluted areas that give background values. Surface water (weekly sampling) and precipitation (daily measurement) are monitored at 6 calibrated catchments, 5 located in southern Norway and 1 in northernmost Norway close to the Russian border. Ground water (weekly sampling) is monitored in 4 reservoirs in Southern Norway. 73 lakes located all over Norway are surveyed each fall. Nineteen rivers in western and southern Norway are monitored by monthly sampling. All sites are considered sensitive to acidification and are chosen to minimise the effects of anthropogenic catchment based impacts. Results from the monitoring over the period 1980–1994 show that there is a reduction of sulphate of about 25–35% in surface waters which is related to a 30–45% reduction in sulphate concentration in precipitation. An improvement in water quality as measured as increase in ANC has only been apparent since 1990. Due to heavy seasalt episodes in the most coastal catchments like Birkenes and the rivers in western Norway, there has been no improvement of ANC since 1980. Deposition of nitrogen has not changed over the last 10 years, and there is no change in the levels of nitrate in the monitored surface waters.     

The retention of trace elements on funnel surfaces of sampling equipment for wet deposition

The retention behaviour of heavy metals from wet deposition on funnel surfaces of wet-only collectors was studied. Two groups of elements were distinguished: (i) elements for which the amount retained was proportional to the concentration in the deposition sample, independent of the exposure time: Cd, Cu and most probably also Ni and V; and (ii) elements for which the amount retained increased with exposure time; Fe and Pb. Percentage retention after an exposure time of 14 d ranged from 5 to 13% for group (i) elements to 7 to 18% for group (ii) elements. The difference in behaviour of the elements of group (i) and (ii) might be attributed to the way these metals are present in precipitation samples. Cadmium and Cu are largely dissolved and show corresponding equilibrium behaviour, while Fe and Pb are to a certain extent present in particles in rainwater, which particles accumulate on the funnel surface. The retention of As, Co, Cr and Mn could not be established because their concentrations were below the detection limits.     

Atmospheric deposition in forest edges measured by monitoring canopy throughfall

Atmospheric dry deposition in two forest edges was studied by means of monitoring canopy throughfall in Douglas Fir stands. Throughfall fluxes in the first 50 to 100 m of forest edges were found to be substantially higher than fluxes in the interior of forest stands. Sodium and chloride showed the steepest throughfall flux gradients. Ions important for soil acidification and eutrophication showed relatively less steep but still significant gradients. The mean increase of the throughfall flux at 10 m, with respect to the flux at 200 m from the forest edge amounted to 150% for Na⁺, 119% for Cl^?, 54% for S0₄ ^2?, 38% for NO₃ ^? , and 39% for NH₄ ⁺ The enhancement of dry deposition in forest edges strongly depends on wind velocity and wind direction during dry deposition. Particularly trees in forest edges exposed to prevailing wind directions receive relatively large amounts of dry deposition.     

Rare earth elements and other trace elements in wastewater treatment sludges

In order to evaluate the possibility of contamination of soil with trace elements by the application of sludges to soil, the contents of rare earth elements (REEs; La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) and other trace elements (Be, As, Ag, Cd, Sb, Cs, Bi, and U) in wastewater treatment sludges were determined. In sludges of night soil treatment plants (night soil sludges) and sludges of wastewater treatment plants in the food industry (food industry sludges), the distribution patterns of REEs normalized versus average REEs in the continental crust were almost flat. It was considered that the REE patterns of uncontaminated sludges reflected the pattern of the continental crust. The crust-normalized REE patterns of sludges of wastewater treatment plants in the chemical industry (chemical industry sludges) and municipal sewage sludges did not always show flat plots. The sludges that did not show a flat REE pattern were considered to be contaminated with some of the REEs.

The coefficient of variation of each element determined among the 10 samples of night soil sludges and the 14 samples of sewage sludges ranged from 34 to 77% and from 26 to 84%, respectively. Among the 10 samples of food industry sludges and the 10 samples of chemical industry sludges, the coefficient ranged from 60 to 143% and from 67 to 172%, respectively. The variations of the content of each element among the food industry sludges or the chemical industry sludges were larger than those among the night soil sludges or the sewage sludges.

The contents of Be, As, Cs, REEs, and U in all the sludges were lower than or the same as those in a field soil. Some of the food and chemical industry sludges contained larger amounts of Ag, Cd, and Sb than the soil. All the night soil sludges and sewage sludges contained much larger amounts of Ag and Bi than the soil.     

Concentration and deposition of trace metals in Ontario-1982

Results of trace metal concentrations in air and precipitation and the corresponding wet and dry deposition in Ontario in 1982 arc reported. In terms of the spatial patterns, in general, there was a decreasing gradient from south-to-north in both concentration and deposition. Patterns differed with each parameter although certain groups of metals (e.g., Fe and Al; Pb, Zn, and Mn) displayed similar patterns. In general, wet deposition was greater than dry deposition at all sites. Geographically, the variability in the wet to dry deposition ratio for coarse particles (MMD > 2.5 μm) was small. However, it increased from the south to the north for fine particles (MMD < 2.5 μm), being higher away from the source areas. Scavenging ratios (W) have been derived from the precipitation and air concentrations of trace metals. The scatter in W is quite large for all trace metals, up to 2 orders of magnitude. There was little seasonal variability in W for fine particles (Pb, Mn, Zn, and Cd). However, coarse particles (Fe, Al, and Cu) were more efficiently scavenged by snow than by rain.     

Atmospheric bulk deposition of trace metals to the Seine river Basin, France: concentrations, sources and evolution from 1988 to 2001 in Paris

Concentrations of Cd, Cu, Ni, Pb and Zn were determined in bulk atmospheric deposition collected at five stations in the Seine River basin (France), to evaluate sources and fluxes of atmospheric trace metals. Bulk deposition (wet + dry) was sampled weekly from March 2001 to February 2002 for 4 sites and from March to December 2001 for the last one. The concentrations of the elements in bulk deposition (dissolved + particulate form) followed the order: Zn > Pb > Cu > Ni > Cd. Concentrations of Zn, Pb and Ni were highly correlated with one another, suggesting a common source, related to the combustion of coal and heavy fuel. Metal concentrations in bulk deposition did not exhibit a high degree of temporal variability over the annual cycle and were not obviously related to meteorological parameters (rainfall, wind). Estimates of the total annual direct atmospheric deposition of metals to the Seine Estuary ranged from 16 kg yr^{? 1} for Cd to 5600 kg yr^{? 1} for Zn. Loadings of Cd, Cu and Ni from direct atmospheric inputs were less than 1% of those contributed by the Seine River and loadings of Pb and Zn represented 1.27% and 1.56% of the Seine contribution. Direct atmospheric inputs are negligible compared to fluvial inputs, but the indirect atmospheric deposition to the estuary was not estimated. Based on these results, trace metal concentrations in Paris have decreased by a factor of 4.6 for Zn and by a factor of 50 for Ni from 1988 to 2001. Of particular interest is the continued decrease in bulk deposition of Pb during this period, underlining the impact of policy initiatives concerning the reduction of lead on emissions in France.     

Release of trace elements from wood ash by nitric acid

Currently wood ash is being used as a soil amendment. Its use is regulated based on trace element content. However, no published information exists on solubilities of trace elements in wood ash. We investigated the release of environmentally-significant trace elements (Cd, Cr, Cu, Pb and Zn) from wood ash as a function of pH and of particle size. Wood ash was sampled from three sources in Maine and sieved into <0.5 mm, 0.5–1 mm, and 1–2 mm fractions. Elemental compositions were determined using a HNO₃/H₂O₂ digestion. Sub-samples (1 g) from each of the nine samples (three sources and three size fractions) were reacted with 50 mLs of standardized HNO₃ for a week using a range of acid concentrations (0.01–0.25 M) to achieve a range in final pH values. The resulting solutions were filtered and analyzed. The compositions of the three wood ashes varied widely. The dominant elements were Si (9.7–34%), Ca (5.8–21%), K (0.8–5.7%), Al (0.8–4.9%), and Mg (0.5–3.0%). Trace elements were present in the following concentrations ranges: Cd (1.9–12 mg kg^?1), Cr (24–92 mg kg^?1), Cu (33–75 mg kg^?1), and Zn (130–1400 mg kg^?1). Both Cd and Zn were released readily from the ashes at final pH values of approximately 6.5 and below. In the final pH range of 3–4, 80–100% of the total Cd and 70–90% of the total Zn was released by the ashes. All three wood ashes showed somewhat different patterns of Cr release. Level of Cr(VI) in a water extract of the ash fractions was found to be a much better predictor of relative Cr solubility than total Cr. Solubility of Cu was low, and Pb was very insoluble. There was little influence of particle size on release of trace elements. The relatively high Cd concentration of wood ash compared with soil, and its relative solubility in wood ash, should be considered in evaluating the potential environmental impact of spreading wood ash on land.     

Atmospheric deposition of heavy metals in central Ontario

As part of a study to determine the magnitude of atmospheric inputs of materials into the lakes of central Ontario, a four-station network of bulk deposition and wet-only precipitation samplers was established in the Muskoka-Haliburton and Sudbury regions to determine the deposition (mg m^2? yr^?1) and volume weighted concentration (μg 1^?1) of Ph, Cu, Ni, Zn, Al, Mn and Fe in precipitation. Large temporal variations in the monthly deposition of all metals were observed. The variations for Cu and Ni exhibited seasonal patterns which could be attributed to a combination of source and wind direction factors. Concentration and deposition of all metals at Muskoka-Haliburton were generally as low or lower than median North American values from the literature. At Sudbury, the large local smelting industry contributed to the elevated Cu, Ni, Zn, and Fe deposition measured in the region (up to two orders of magnitude larger than Muskoka-Haliburton); Al and Mn values were not elevated. Deposition of Cu. Ni and Fe was inversely related to distance from the largest point source at Sudbury. The importance of dry deposition is greatest at Sudbury where dry inputs of Cu, Zn, Al, and Fe generally exceed wet inputs. In contrast, wet deposition of metals at Muskoka-Haliburton predominates over dry. Calculation of an enrichment factor (normalized against Mn) showed that the levels of Pb, Cu, Ni and Zn observed in the precipitation of central Ontario require an additional non-crustal source (either natural or anthropogenic) for explanation.     

Uptake of 15 trace elements in arbuscular mycorrhizal marigold: Measured by the multitracer technique

The effect of arbuscular mycorrhizal (AM) colonization on the uptake of trace elements in marigold (Tagetes patula L.) was studied using a multitracer consisting of radionuclides of ⁷Be, ²²Na, ⁴⁶Sc, ⁵¹Cr, ⁵⁴Mn, ⁵⁹Fe, ⁵⁶Co, ⁶⁵Zn, ⁷⁴As, ⁷⁵Se, ⁸³Rb, ⁸⁵Sr, ⁸⁸Y, ⁸⁸Zr, and ^95mTc. Marigold plants were grown under controlled environmental conditions in sand culture either without mycorrhizas or in association with an AM fungus, Glomus etunicatum. The multitracer was applied to the pot, and plants were harvested at 7 and 21 d after tracer application. We found that the uptake of ⁷Be, ²²Na, ⁵¹Cr, ⁵⁹Fe, ⁶⁵Zn, and ^95mTc was higher in the mycorrhizal marigolds than in the non-mycorrhizal ones, while that of ⁴⁶Sc, ⁵⁶Co, ⁸³Rb, and ⁸⁵Sr was lower in the mycorrhizal marigolds than in the non-mycorrhizal ones. Thus, the multitracer technique enabled to analyze the uptake of various elements by plant simultaneously. It is suggested that this technique could be used to analyze the effects of AM colonization on the uptake of trace elements by plant.     

Characterization of major and trace elements in sclerotium grains

Sclerotium grains in soil contain humus-metal complexes that are probably produced from fungal metabolites. The characterization of major elements in sclerotium grains collected from volcanic ash soils in Mt Myoko was examined by X-ray photoelectron spectroscopy, FT-IR spectrometry and CHN analysis, and the concentration of trace elements was determined by PIXE (particle induced X-ray emission spectrometer) analysis. The content of major elements, C, H, N, O and Al, was approximately 47.6, 3.32, 0.78, 30.2 and 1.4% by mass, respectively. Trace elements such as Ti, Cr, Mn, Cu, Zn, Br and Pb were detected in the grains at concentrations between 10 and 100 μg g⁻¹. Functional carbon groups for the whole grain were characterized by the dominance of O-alkyl C associated with aromatic C. The comparison between the surface and subsurface (matrix) of the grain showed that the concentrations of O, C and N were relatively greater on the surface of sclerotium grains than in the matrix. The proportion of carbon having C–O, C=O, and O–C=O bonds, O and N showed a tendency to decrease from the surface towards the matrix. The proportion of C assigned as C–C and/or C–H bonds had a tendency to increase towards the matrix associated with Al.