A European survey of atmospheric heavy metal deposition in 2000-2001

The background, administration and current status of the monitoring programme "European Survey of Atmospheric Heavy Metal Deposition" is described. All European states are invited to join the survey 2000-2001. The co-ordination and responsibility for the survey will gradually be transferred from the Nordic Council of Ministers to the International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops (ICP Vegetation).     

Long-term changes of acidifying deposition in Finland (1973-2000)

The long-term changes of acidifying deposition in Finland during the period 1973-2000 were studied using bulk deposition data from 19 stations belonging to the national monitoring network. The regional-scale approach (southern, central and northern Finland) was used for trend assessment with respect to implementation of European sulphur (S) emission reduction amendments involving deposition changes prior to (1973-1985) and after (1986-2000) the agreements (S protocols in 1985 and 1994). There were no marked changes in sulphate deposition between the 1970s and 1980s and consistent trends in 1973-1985 were not observed. Deposition of nitrogen (N) compounds, particularly NO3-N, were increasing between the 1970s and 1980s. Deposition of base cations exhibited a slight decline throughout the 1970s and 1980s. Decrease of calcium and magnesium deposition without corresponding decrease in sulphate resulted in increased acidifying potential (AP) of deposition. Due to successful implementation of S (and N) emission reduction measures, sulphate deposition has decreased substantially (30% in northern and up to 60% in southern Finland) since the late 1980s. N deposition also decreased, but less than S deposition. Base cation deposition has also declined substantially, but this decline appeared to be leveling off during the 1990s, accounting for the decrease of AP in deposition. The observed deposition pattern is in agreement with the on-going biochemical recovery of acidified small Finnish lakes taking place since the early 1990s.     

Determination of vapor pressure-temperature relationships of current-use pesticides and transformation products

Sub-cooled liquid vapor pressures (P(L)(0)) of current-use organochlorine and organophosphate pesticides (chlorothalonil, chlorpyrifos methyl, diazinon, fipronil) and selected transformation products (chlorpyrifos oxon, heptachlor epoxide, oxychlordane, 3,5,6-trichloro-2-pyridinol) were determined at multiple temperatures using the gas chromatography retention time technique. Results were utilized to determine vapor pressure-temperature relationships and to calculate enthalpies of vaporization (DeltaH(vap)). While results for chlorothalonil and diazinon were comparable with published values, the measured value for fipronil (1.82 x 10(-6) Pa) is almost an order of magnitude higher than the reported literature value (3.7 x 10(-7) Pa). The availability of vapor pressure temperature relationships for these chemicals will aid in pesticide risk assessment development and improve the effectiveness of mitigation and remediation efforts.     

Sphagnum fuscum moss as an indicator of atmospheric cadmium deposition across Canada

The concentration of cadmium was determined in samples of Sphagnum fuscum moss collected from 37 sites across Canada from the Pacific Ocean to the Atlantic Ocean and Labrador Sea. At 22 of the sites, Cd was less than 0.2 mg kg(-1), the detection limit. Elevated Cd levels were only found in mosses collected in the vicinity of the smelters at Flin Flon, Manitoba, and Rouyn-Noranda, Quebec, where a maximum concentration of 12 mg kg(-1) was measured.     

Long-term atmospheric bulk deposition of polycyclic aromatic hydrocarbons (PAHs) in rural areas of Southern Germany

A novel passive sampling technique using a funnel–adsorber–cartridge device was adopted and validated in the field during a long-term monitoring program on the atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in three rural regions of southern Germany. Apart from seasonal variations, fairly stable annual deposition rates around 200 μg m⁻² yr⁻¹ for the sum of PAHs were obtained. The time-integrating passive samplers showed that spatial variability due to topography was negligible and differences between open-field and forest deposition were within a factor of 2. Based on correlations with ambient temperature, advection was identified as the most important factor that controls the atmospheric deposition of PAHs. Gas-adsorption contributes significantly to the deposition of the semivolatile compounds in forests, but particle deposition seems to be the major pathway for all PAHs.     

Globalization and multi-spatial trends in the coverage of protected-area conservation (1980-2000)

This study is focused on the global expansion of protected-area coverage that occurred during the 1980--2000 period. We examine the multi-scale patterning of four of the basic facets of this expansion: i) estimated increases at the world-regional and country-level scales of total protected-area coverage; ii) transboundary protected areas; iii) conservation corridor projects; and iv) type of conservation management. Geospatial patterning of protected-area designations is a reflection of the priorities of global conservation organizations and the globalization of post-Cold War political and economic arrangements. Local and national-level factors (political leadership and infrastructure) as well as international relations such as multilateral and bilateral aid combine with these globalization processes to impact the extent, type, and location of protected-area designations. We conclude that the interaction of these factors led to the creation and reinforcement of marked spatial differences (rather than tendencies toward worldwide evenness or homogenization) in the course of protected-area expansion during the 1980--2000 period.     

The effect of atmospheric mercury depletion events on the net deposition flux around Hudson Bay,Canada

Atmospheric Mercury Depletion Events (AMDE) occur in Arctic and Antarctic regions during polar sunrise. During AMDE, reactive gaseous Hg is rapidly formed through in-situ oxidation of gaseous Hg⁰ by halogens, notably atomic Br and radical BrO. This leads to high Hg deposition fluxes yet an unknown fraction of deposited Hg is reemitted to the atmosphere through subsequent photo-reduction, so that the net deposition flux related to AMDE is not well constrained. Here, Hg and halogens were measured in lichens hanging in tree branches around Hudson Bay where AMDE were reported. Hg concentrations are strongly correlated to halogen elements Br, Cl and I (r² of 0.91, 0.76, 0.81) and decrease with distance from Hudson Bay. We interpret this trend as the result of AMDE, supported by a 1D numerical Br and BrO oxidation model for Hg⁰. Organic carbon normalized Hg contents of down-core lake sediments reported in the literature also show a decreasing trend away from Hudson Bay. Combined observations suggest that at least 50% of Hg deposited during AMDE is reemitted to the atmosphere. Finally, the latitudinal Hg gradient observed in lake sediments suggests that AMDE were active in the Hudson Bay area during the last 90 to 200 years.     

Changes in the atmospheric deposition of minor and rare elements between 1975 and 2000 in south Sweden, as measured by moss analysis

Elements emitted to the atmosphere are partly exported to more remote areas and contribute to the regional and territorial deposition rates. This study is based on the principle that carpet-forming bryophytes (pleurocarpic mosses) absorb elements and particles from rain, melting snow and dry deposition. We compare the concentrations of 60 elements in carpets of the forest moss Pleurozium schreberi sampled in 1975 and 2000 within a sparsely inhabited area dominated by forest and bogland in south Sweden. As an average for all the 60 elements, the median concentration was 2.7 times higher in 1975 than in 2000. The greatest difference was measured for Pb, although In, Bi, Ge, V, Sn, As and Ag had more than 5 times higher concentrations in 1975 than in 2000. Somewhat lower 1975/2000 concentration ratios (3.0-3.8) were measured for U, Sb, Cd, W, Ga, Fe, Li, and Be. The rare-earth elements (Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), except Eu as well as Th, Ni, Al, Ti, Hf, Nb, and Zr, had concentration ratios around the average (2.5-2.8). Possible causes of these changes are discussed. We conclude that reductions in anthropogenic dust emissions during recent decades have decreased the atmospheric deposition over northern Europe of most elements in the periodical system, as previously reported for a limited number of transition and heavy metals. Changes in the deposition of soil dust would be of minor importance to the decreased deposition rates.     

Atmospheric deposition of organochlorines (PCBs and pesticides) in northern France

Bulk deposition measurements were made in northern France for a number of organochlorines (PCBs, HCB, pp'DDE, alpha-HCH and gamma-HCH) over a 1-y period, at urban, semi-rural, rural and forest sites located in accordance with prevailing wind direction. The west-east rise of PCB bulk deposition (average annual values as sigma 7) ranged from 12.2 to 46.8 ng l(-1) and showed the anthropogenic influence arising from towns, industries, storage areas and landfills over continental areas. The values were maximal at the urban site 3, Paris (122 ng l(-1)) and were still high at the eastern site 6, Abreschviller near landfills (62 ng l(-1)). Also, the highest annual deposits were found at sites 3 and 6 (Paris and Abreschviller), 38.6 and 47.3 microgm-2, respectively, i.e. 3.6 and 4 times higher than the western site value: Pleumeur. A temporal trend was observed, at the urban site where a rise occurred (up to 441 ng l(-1)) in March and April. PCB distribution according to the chlorination degree displayed high proportions of 3 Cl and 4 Cl congeners, particularly in the forest area. Annual gamma-hexachlorocyclohexane (gamma-HCH) concentration values at sites 1 (Ouessant) and 2 (Pleumeur) were close to the background noise (1.7 ng l(-1)). At the agricultural (4) and the urban (3) sites, values were maximal (19.2 and 15.9 ng l(-1)) with peaks in spring and autumn. At Pleumeur, without any local input, negative correlations were found between PCB/temperature (r = -0.503, p < 0.05), HCB/temperature ( r = -0.549, p < 0.01) and gamma-HCH/temperature ( r = -0.675, p < 0.01). A clear influence of south-west winds upon the magnitude of PCB fluxes throughout the sites was noticed. Whereas there was no global decrease of PCB contamination since 1986, the general trend of gamma-HCH total deposits was a 10-time fall, as a result of the restricting legislation in use.     

Ecosystem effects of atmospheric deposition of nitrogen in The Netherlands

Atmospheric deposition of inorganic N, mainly ammonium volatilized from manure produced in intensive stockbreeding, on sensitive terrestrial and aquatic ecosystems in The Netherlands is in the order of 40 to 80 kg ha(-1) year(-1). Proven effects of this deposition are (i) eutrophication with N, leading to floristic changes (ii) acidification of base-poor sandy soils and of moorland pools, leading to higher concentrations of dissolved, potentially toxic metals such as Al3+, and (iii) increased levels of nitrate in groundwater below woodlands. In acid forest soils, but not in soils under heathland, nitrification and leaching of nitrate is common. However, in very poor sandy forest soils and at very high ammonium inputs, nitrification may be too slow to prevent the development of high concentrations of ammonium. Both excessive acidification and excessive levels of ammonium probably play an important role in the general forest decline, which is most severe in the southern and central parts of the country, where ammonium inputs are highest.     

Long-term investigation of atmospheric mercury contamination in Connecticut.

Atmospheric mercury was monitored from January 1997 through the end of December 1999 in eight sampling locations in Connecticut. Four sampling locations were chosen along the shores of Long Island Sound and four were chosen in interior sections of Connecticut. Sampling locations were chosen to represent both rural and urban sectors. Average concentrations of gaseous and particulate mercury were found to be 2.06 ng/m3 and 10.5 pg/m3, respectively. The weekly average wet deposition fluxes of mercury and methylmercury over the three-year sampling period were measured to be 611 and 11 microg/ha/week, respectively. Concentrations of gaseous, particulate and wet flux of mercury were found to be significantly higher in urban areas than the rural sampling locations. There was, however, no significant difference between the mean gaseous and particulate concentrations of mercury in coastal and inland sampling locations. No significant difference was observed either between the wet fluxes of total mercury in coastal and inland sampling locations and there was no spatial gradient for mercury concentration and deposition. The data of this study suggest that vehicular traffic and localized emission sources in urban areas play a significant role in determining the atmospheric concentration of mercury in Connecticut.     

Contamination by chlorinated pesticides, PCBs and PBDEs in Atlantic spotted dolphin (Stenella frontalis) in western South Atlantic

Chlorinated pesticides, PCBs and PBDEs were analysed in nine blubber samples of Atlantic spotted dolphins, Stenella frontalis, incidentally captured during fishing operations in southern and southeastern Brazil between 2005 and 2007. The majority of compounds analysed were detected, suggesting widespread contamination over the region. Although the samples came from a location far from main coastal industrial areas, the results revealed an influence from such sources. Therefore, levels of PCBs (774-23 659 ng g⁻¹ lipid wt.) and PBDEs (23-1326 ng g⁻¹ lipid wt.) detected seem to be related to the movement of individuals throughout near-shore and offshore waters. The sample from a lactating female exhibited a lower level of contamination and a distinct pattern, indicating selective transfer favouring less lipophilic compounds.     

Modeling atmospheric mercury deposition in the vicinity of power plants

Two mathematical models of the atmospheric fate and transport of mercury (Hg), an Eulerian grid-based model and a Gaussian plume model, are used to calculate the atmospheric deposition of Hg in the vicinity (i.e., within 50 km) of five coal-fired power plants. The former is applied using two different horizontal resolutions: coarse (84 km) and fine (16.7 km). More than 96% of the power plant Hg emissions are calculated with the plume model to be transported beyond 50 km from the plants. The grid-based model predicts a lower fraction to be transported beyond 50 km: >91% with a coarse resolution and >95% with a fine resolution. The contribution of the power plant emissions to total Hg deposition within a radius of 50 km from the plants is calculated to be <8% with the plume model, <14% with the Eulerian model with a coarse resolution, and <10% with the Eulerian model with a fine resolution. The Eulerian grid-based model predicts greater local impacts than the plume model because of artificially enhanced vertical dispersion; the former predicts about twice as much Hg deposition as the latter when the area considered is commensurate with the resolution of the grid-based model. If one compares the local impacts for an area that is significantly less than the grid-based model resolution, then the grid-based model may predict lower local deposition than the plume model, because two compensating errors affect the results obtained with the grid-based model: initial dilution of the power plant emissions within one or more grid cells and enhanced vertical mixing to the ground.     

Atmospheric deposition of organochlorine pesticides by precipitation in a coastal area

Wet deposition fluxes of organochlorine pesticides (OCPs) were determined for rain samples collected in a coastal area of Turkey. Seventeen precipitation samples were collected over a 1-year period from 2008 to 2009. Rainwater was accumulated at the beginning of rain events using real time monitoring. Atmospheric concentrations were also measured in parallel with deposition samples. Both atmospheric concentrations and deposition fluxes were determined as particle and gas phases. The particle phase and dissolved phase deposition fluxes were 794.26?±?756.70 ngm^?2 day^?1 and 800.77?±?672.63 ngm^?2 day^?1, respectively. The washout ratios for OCP compounds were calculated separately for the particle and dissolved phases using the atmospheric concentrations and rain concentrations. The minimum washout ratio for the particle phase was 2339.47 for Endrin aldehyde, whereas the maximum washout ratio was 497593.34 for Methoxychlor. The maximum washout ratio for the dissolved phase was 247523.89 for Endosulfan beta, whereas the minimum washout ratio was 10169.69 for p,p′-DDT. The dry deposition velocities ranged from 0.01 to 1.67 cms^?1. The partitioning of wet deposition between the particle and dissolved phases was 50 % in terms of total OCP deposition.     

Characterization of atmospheric dry deposition particulates in Kobe, Japan

The sources and character of individual metal and metalloid particles from atmospheric dry depositions in Kobe, Japan were investigated. Japan faces long-range pollutant transportation from northeastern Asia during winter and spring. Information regarding their properties and sources is useful for evaluating their affects on the environment and human health. Individual metal and metalloid particles that were collected for every 24 h on the plate, which was designed to reduce a local turbulence, were characterized for their composition, diameter, and deposition fluxes using a field emission scanning electron microscope with an energy dispersive X-ray spectrometer. Approximately 3,000 metal and metalloid particles were classified into 14 types based on their composition and further classified into four groups based on their distribution patterns. They are (A) Fe-O, Fe-Ba-Sb-Cu-S-Ti-O, Fe-Zn-O, Zn-O, Ni-O, and Mn-Fe-O; (B) Cu-Zn-O and Cu-Sn-O; (C) Pb-O, Sn-Sb-O, and Ag-O; (D) Pb-Zn-Cl-Si-S-O and Bi-Cl-O. From these data, this study suggests their sources as the Asian continent (Group A), local source (Group B), multiple sources (Group C), and incineration process (Group D). This study shows (1) the sources and character of individual metal and metalloid particles from short-term atmospheric depositions in Kobe, Japan and (2) application of individual particle analysis for atmospheric depositions.     

Reconciling models and measurements to assess trends in atmospheric mercury deposition

Changes in atmospheric mercury deposition are used to evaluate the effectiveness of regulations controlling emissions. This analysis can be complicated by seemingly incongruent data from different model runs, model types, and field measurements. Here we present a case study example that describes how to identify trends in regional scale mercury deposition using best-available information from multiple data sources. To do this, we use data from three atmospheric chemistry models (CMAQ, GEOS-Chem, HYSPLIT) and multiple sediment archives (ombrotrophic bog, headwater lake, coastal salt marsh) from the Bay of Fundy region in Canada. Combined sediment and modeling data indicate that deposition attributable to US and Canadian emissions has declined in recent years, thereby increasing the relative significance of global sources. We estimate that anthropogenic emissions in the US and Canada account for 28-33% of contemporary atmospheric deposition in this region, with the rest from natural (14-32%) and global sources (41-53%).     

Estimates of synthetic fertilizer N-induced direct nitrous oxide emission from Chinese croplands during 1980-2000

There is increasing concern that agricultural intensification in China has greatly increased N₂O emissions due to rapidly increased fertilizer use. By linking a spatial database of precipitation, synthetic fertilizer N input, cropping rotation and area via GIS, a precipitation-rectified emission factor of N₂O for upland croplands and water regime-specific emission factors for irrigated rice paddies were adopted to estimate annual synthetic fertilizer N-induced direct N₂O emissions (FIE-N₂O) from Chinese croplands during 1980-2000. Annual FIE-N₂O was estimated to be 115.7 Gg N₂O-N year⁻¹ in the 1980s and 210.5 Gg N₂O-N year⁻¹ in the 1990s, with an annual increasing rate of 9.14 Gg N₂O-N year⁻¹ over the period 1980-2000. Upland croplands contributed most to the national total of FIE-N₂O, accounting for 79% in 1980 and 92% in 2000. Approximately 65% of the FIE-N₂O emitted in eastern and southern central China.     

Seasonal variability and source apportionment of metals in the atmospheric deposition in Belgrade

The primary objective of this study is to assess anthropogenic impacts on the environment by determination of element atmospheric depositions. Bulk depositions were collected monthly, from June 2002 to December 2006, at three urban locations in Belgrade. Concentrations of Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb were analyzed by atomic absorption spectrometry and the current deposition fluxes of atmospheric metals were established. Fourier analysis was applied in order to investigate seasonal variation of the monthly data set. Nickel, V, Fe and Al showed pronounced seasonal dependence, while seasonal variation of the other elements was not evident. The enrichment factors of Pb, Zn, Cd and Cu were obviously above those who could have been caused by natural processes, indicating a mainly anthropogenic origin. Nickel was intermediately enriched suggesting participation of both natural and anthropogenic sources. The multivariate receptor model, Unmix, was used to analyze a 5-yr element atmospheric depositions data set. Three main source profiles (mixed road dust, oil combustion and metal processing) were identified and the overall average percentage source contributions determined.     

Spatial distribution of atmospheric PAHs and PCNs along a north-south Atlantic transect

Ship-board air samples collected between The Netherlands and South Africa in January-February 2001 were analysed for polycyclic aromatic hydrocarbons (PAHs) and polychlorinated naphthalenes (PCNs). The highest PAH concentrations occurred in the European samples, and in samples close to West Africa and South Africa. Consistently low PAH concentrations were measured in the southern hemisphere open ocean samples (190-680 pg/m3). The highest PCN concentrations occurred in the European samples, but high values were also detected off the West African coast, and in the sample taken closest to South Africa. Data are presented for diurnal cycles taken in the remote South Atlantic. The day:night ratios of phenanthrene, 1-methylphenanthrene and fluoranthene were typically approximately 1.5-2.5:1. The mechanism(s) causing this observation is/are not understood at present, but dynamic environmental process(es) is/are implicated.     

南宁市郊空气和大气干湿沉降物中多环芳烃的污染特征

采用空气被动采样器和大气干湿采样器分夏、冬季采集大气及其干湿沉降物样品,利用气相色谱-质谱联用仪测定16种多环芳烃(PAHs)优先控制污染物。结果表明:冬、夏季大气干湿沉降物中PAHs的平均值分别为581.06、174.59ng/(m2·d),冬季PAHs的组成以2～3环PAHs为主,夏季以4～6环PAHs为主;冬、夏季空气中PAHs的平均值分别为149.16、168.70ng/d,均以2～3环PAHs为主。大气干湿沉降物PAHs的沉降通量时空变化为:冬季,商住文教混合区农业区工业区;夏季,工业区农业区商住文教混合区;冬季大于夏季3.3倍。空气PAHs沉降通量的时空变化为:冬季,工业区商住文教混合区农业区;夏季,农业区工业区商住文教混合区;冬季略低于夏季。