Seasonal patterns of heavy metal deposition to the snow on Lambert Glacier basin,East Antarctica

Al, V, Mn, Fe, Cu, As, Cd, Ba, Pb, Bi and U were determined in a continuous series of 46 snow samples from a 2.3-m snow pit, covering the time period from austral spring 1998 to summer 2002, at a site on the east side of the Lambert Glacier basin in East Antarctica. Concentrations are very low for all metals and differ by orders of magnitude from one metal to another, with the mean concentrations ranging from 0.028 pg g⁻¹ for Bi to 165 pg g⁻¹ for Al. It is estimated that anthropogenic contributions are dominant for Cu, Pb and probably As, in the snow in our study area while the natural contributions from rock and soil dust, sea-salt spray and volcanic emissions account for most of the measured concentrations of the other metals. Our snow profiles show pronounced seasonal variations for Mn, As, Ba, Pb and Bi throughout the year, but a very different situation is observed between different metals. These observations suggest that heavy metals determined in our samples are controlled by different transport and deposition mechanisms related to physical and chemical alterations in the properties and sources of aerosol.     

Geographical variations of major and trace elements in East Antarctica

Surface snow samples have been analyzed for a total of 37 elements including Na, Mg, Al, K, Ca, Fe, Ba, Cd, Fe, Cd, Cr, Cu, Ga, Li, Mn, Pb, Se, Sr, V, Zn, As, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Th by inductively coupled plasma mass spectroscopy (ICP-MS). Rare earth elements in surface snow were evaluated after preconcentration of the samples in a class 1000 clean room. These samples were collected between 1991–1993 during the oversnow traverses along a 2200 km route in East Queen Maud Land, Antarctica. They include one at Dome Fuji Station (77°32′S, 24°08′E; 3810 m a.s.l.) built on the top of the second highest dome. In coastal area, fallout flux for Na, Mg, Sr and Cu or more weakly for Ca and Ba shows an apparent decrease according to the distance from the coast. On the other hand, fallout flux for Co, Ni and Cd shows an increase at 2500–3000 m or >3500 m above sea level. For Mn, Se, Zn and As, it shows a combined pattern of these two types. For Al, V and Pb, a constant profile with an intermittent peaks along this route was indicated. These geographical distributions of fallout flux for each element could reflect polar stratospheric precipitation or long-range tropospheric transport from the southern hemisphere. In the present study, concentrations of rare earth elements in Antarctic surface snow at sub-ppt level are first reported. A clear rare earth pattern is noticed in the Antarctic samples and rare earth ratios are also valuable to estimate anthropogenic emissions to the Antarctica.     

Heavy metal distribution in dust from elementary schools in Hermosillo,Sonora, México

The city of Hermosillo, Sonora in northern Mexico was investigated for its heavy metals content. Samples of sedimented dust in roofs from 25 elementary schools were analyzed for their contents of Ni, Cr, Zn, Cd, Co, Ba, V, Pb, Fe and Cu after digestion with nitric acid. The results of the analysis were used to determine spatial distribution and magnitude of heavy metals pollution. The results of this study reveal that heavy metals distribution is different in two areas of the city. The southern area contains higher concentrations of heavy metals than the northcentral area. The mean level of Cd in exterior dust is 5.65 mg kg⁻¹ in the southern area whereas the mean level of Cd is 2.83 mg kg⁻¹ in the northcentral area. Elevated concentrations of Zn (2012 mg kg⁻¹), Pb (101.88 mg kg⁻¹), Cr (38.13 mg kg⁻¹) and Cd (28.38 mg kg⁻¹) in roof dust were found in samples located near industrial areas. Principal component analysis (PCA) was applied to the data matrix to evaluate the analytical results and to identify the possible pollution sources of metals. PCA shows two main sources: (1) Pb, Cd, Cr and Zn are mainly derived from industrial sources, combined with traffic sources; (2) Fe, Co and Ba are mainly derived from natural sources. V and Ni are highly correlated and possibly related to fuel combustion processes. Enrichment factors were calculated, which in turn further confirms the source identification. Ba and Co are dominantly crustal. Anthropogenically added Cd, Pb, Zn and Cr show maximum enrichment relative to the upper continental crustal component. The distribution of the heavy metals in dust does not seem to be controlled only by the topography of the city, but also by the location of the emission sources.     

Mass levels,crustal component and trace elements in PM10 in Palermo,Italy

Results concerning the levels and elemental compositions of daily PM₁₀ samples collected at four air quality monitoring sites in Palermo (Italy) are presented. The highest mean value of PM₁₀ concentrations (46 μg m⁻³, with a peak value of 158 μg m⁻³) was recorded at the Di Blasi urban station, and the lowest at Boccadifalco station (25 μg m⁻³), considered as a sub-urban background station. Seventeen elements (Al, As, Ba, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Sb, Sr, U, V, Zn) were measured by ICP-MS. Al and Fe showed the highest concentrations, indicating the significant contribution of soil and resuspended mineral particles to atmospheric PM₁₀. Ba, Cr, Cu, Mn, Mo, Ni, Pb, Sb, V and Zn had higher concentrations at the three urban sampling sites than at the sub-urban background station. Besides soil-derived particles, an R-mode cluster analysis revealed a group of elements, Mo, Cu, Cr, Sb and Zn, probably related to non-exhaust vehicle emission, and another group, consisting of Ba, As and Ni, which seemed to be associated both with exhaust emissions from road traffic, and other combustion processes such as incinerators or domestic heating plants. The results also suggest that Sb, or the association Sb–Cu–Mo, offers a way of tracing road traffic emissions.     

Coarse atmospheric aerosol: size distributions of trace elements

A sampler, employing nine single stage impactors placed in parallel within a portable wind tunnel, has been used to determine the metal content of coarse atmospheric aerosol. The wind tunnel maintains a constant flow environment for the collectors housed inside it, so that representative sampling conditions are achieved compared to the varied ambient wind conditions. At a flow rate of 8 m s⁻¹ the 50% cut-off diameters of the impactors ranged from 7.8 to 38.8 μm. Measurements were conducted at a rural and urban site near Colchester in south east England. The samplers were analysed by PIXE for P, K, Ca, Fe, Ti, Mn, Cu, V, Co, Cr, Br, Zn, Ni, Sc and Pb. It is found that the sampler can be employed to quantitatively characterise the elemental mass size distribution for aerosol larger than 10 μm. The results indicate that a small fraction of the above earth and trace elements’ metal mass is present in particles greater than 10 μm. This fraction for earth metals (Ca, K, Ti) is comparatively greater in the rural site than the urban site, while for trace metals (Mn, V, Cu, Cr) this fraction constitutes a more significant part of the coarse mass at the urban site. Trace element concentrations were of a similar order of magnitude to earlier literature reports. Although the number of measurements was limited it can be concluded that the size distributions obtained were characteristic of an unpolluted area.     

The use of a sequential leaching procedure for heavy metal fractionation in green liquor dregs from a causticizing process at a pulp mill

A five-stage sequential leaching procedure was used to fractionate heavy metals (Cd, Cu, Pb, Cr, Zn, Fe, Mn, Ni, Co, As, V, Ba and Ti) in green liquor dregs into the following fractions: (1) water-soluble fraction (H2O), (2) exchangeable fraction (CH3COOH), (3) easily reduced fraction (HONH3Cl), (4) oxidizable fraction (H2O2 + CH3COONH4), and (5) residual fraction (HF + HNO3 + HCl). The green liquor dregs were derived from a causticizing process at a pulp mill at Kemi, Northern Finland. According to the leaching studies, the leachability of heavy metals in the water-soluble fraction varied between 0.5 and 2 mg kg(-1) expressed on a dry weight (d.w.) basis, indicating relatively low bioavailability of the metals. However, the concentration of Mn (2065 mg kg(-1); d.w.) showed a strong and of Zn (17.6 mg kg(-1); d.w.), Ni (39.7 mg kg(-1); d.w.) and Ba (32.0 mg kg(-1); d.w.) slightly tendency to be extracted in the exchangeable fraction. In addition, Zn, Mn, Ni, Co, V and Ba showed clear leachability in the easily reduced fraction, as well as Cd, Cu, Cr, Zn, Mn, As and Ba in the oxidizable fraction. For Cd, Cu, Cr, Zn, Mn, Ni, Co, Ba and Ti, the sum of leachable heavy metal concentrations in fractions 1-5 agreed relatively well with the "total" heavy metal concentrations. Recoveries of the sum of fractions 1-5 were 84-56% of those obtained by the US EPA method 3052 (i.e. concentrations obtained after microwave oven digestion with a mixture of HF and HNO3).     

Physicochemical characterisation of diesel exhaust particles: Factors for assessing biological activity

A range of microscopy and analytical techniques have been used to investigate the physicochemical properties of diluted DEP that may be important in determining its biological activity. Transmission electron microscopy demonstrated four basic categories of particle morphology: (1) “spherulites” [individual particles]; (2) “chains” or “clusters” of spherulites; (3) “spherules”, [large bodies of spherulites]; (4) “flake-like bodies”. Image analysis of TEM photomicrographs determined empirical morphological parameters (30 nm mean spherulite diameter, aspect ratio 1.5, mean particle area 0.078 μm, equivalent spherical diameter 0.23 μm, roundness 2.76) and derived parameters (0.313 μm² surface area, 3.7 μm² pg surface area per mass and 0.042 μm³ volume) of DEP. Distributions of the particle sizes by number showed 10.1% were ultrafine (<0.1 μm), 89.5% fine (0.1–2.0 μm), 0.4% coarse (>2.5 μm), but distributions based on a mass value were different (0.01% ultrafine; 52.6% fine, 47.4% coarse). In contrast, impacted DEP contained 60.87% ultrafine, 39.13% fine and 0% coarse particles by number. Field emission scanning electron microscopy of spherulites revealed smooth surfaces and flocculated spherules with large surface areas. Electron probe X-ray micro-analysis demonstrated the presence of C, O, Na, Mg, K, Al, Si, P, S, Cl, Ca along with a range of metals (Ti, Mn, Fe, Zn, Cr), that were heterogeneous in distribution. Inductively coupled plasma mass and atomic emission spectrometry identified Mg, P, Ca, Cr, Mn, Zn, Sr, Mo, Ba, Na, Fe, S, and Si as the mobile sorbed metals readily removed during sonication in water from DEP suspensions. X-ray Diffraction confirmed previous observations of the presence of nanometer sized crystallites of disordered graphite. Comparison of microscopy and analytical results between sonicated and impacted DEP revealed a physicochemical difference that must be taken into account in any toxicological investigations.     

应用地质累积指数评价抚顺市PM10中元素的污染

2006-2007年采暖季、风沙季和非采暖季分别在抚顺市的6个采样点采集PM10样品,用等离子体原子发射光谱(ICP-AES)法测定样品中Ti、Al、Mn、Mg、Ca、Na、K、Cu、Zn、As、Pb、Cr、Ni、Co、Cd、Fe、V等17种元素的含量,并用地质累积指数对其污染状况进行初步评价。结果表明:(1)从PM10中元素在不同采样点的含量看,抚顺市PM10中Ti、Mn、Mg、Cu、Zn、Pb、Cr、Ni、Co这9种元素在各采样点间的差别较大;Al、Ca、Na、K、As、Cd、Fe、V这8种元素差别较小。(2)从PM10中元素在不同采样季的含量看,抚顺市PM10中Mn、Mg含量的季间差别较大,其余15种元素季间差别较小。(3)Zn、Cd污染较重;Ti、Al、Mg、Ca、Na、K、As、Fe和V污染较轻;其他6种元素在6个采样点和3个采样季污染程度差别较大。(4)水库采样点各元素污染级别均不是最高;新华采样点PM10中Cu、Zn、Pb、Cr、Ni、Co、Cd污染级别均较高。(5)3个采样季PM10中Cd、Zn污染均较重,属于重度或严重污染;在采暖季PM10中Cu、Pb、Cr的地质累积指数较风沙季、非采暖季大;在非采暖季PM10中Mn、Co受到的污染比采暖季和风沙季稍严重。     

Impact of mineral components and selected trace metals on ambient PM10 concentrations

PM10 levels of the mineral components Si, Al, Fe, Ca, Mg and some trace metals were measured at three different sites in the urban area of Vienna (Austria). Observed trace metal concentrations varied between less than 0.1 ng m^?3 (Cd) and approximately 200 ng m^?3 (Zn), mineral components showed enhanced concentrations ranging from 0.01 μg m^?3 (Ca) to 16.3 μg m^?3 (Si). The contribution of the respective mineral oxides to PM10 mass concentrations accounted on average for 26.4 ± 16% (n = 1090) of the PM10 mass, with enhanced rates in spring and autumn (monthly averages of up to 40%) and decreased contributions in the cold season (monthly averages below 10%). The atmospheric occurrence of Al, Ti and Sr could be assigned to crustal sources, whereas for the elements Ba, Ca, Fe, Mg, Mn and V an increased contribution of non-crustal origin was observed. PM10 levels of As, Cd, Co, Cr, Cu, Ni, Pb, Sb, Sn and Zn were predominantly derived from man-made emissions. Intersite comparison indicated that urban PM10 mass concentrations and PM10 levels of As, Pb and Zn were predominantly influenced from the transport of aerosols from outside into the city, whereas for the elements Ba, Mg, Ca, Cu and Fe a distinctly increased impact of local emissions was observed. The contribution of these urban emissions to total PM10 concentrations was estimated by calculating the so-called “urban impact”, which was found to be 32.7 ± 18% (n = 392) in the case of PM10 mass concentrations. The investigated elements accounted on average for 31.3 ± 19% (n = 392) of the observed PM10 mass increase. The mean values for the “urban impacts” of individual elements varied between 25.5% (As) and 77.0% (Ba).     

Size distribution and sources of trace metals and n-alkanes in the Athens urban aerosol during summer

Size-resolved, 24-h aerosol samples were collected from June–July 2001 by means of an Andersen high-volume cascade impactor. Sampling was conducted in a central avenue (Patission) characterised by heavy traffic, 21 m above street level, in the Athens city centre. Samples were analysed by atomic absorption spectrometry and gas chromatography to determine the size distribution of nine metallic elements (Cd, Pb, V, Ni, Mn, Cr, Cu, Fe, Al) and n-alkanes (with carbon numbers in the range 18–35). The aerosol mass median diameter (MMD) was calculated by means of probit analysis on the cumulative mass concentration size distribution for each metals and n-alkane. The total n-alkane mass concentration (TNA) in total suspended particles (TSP) ranged from 72 to 1506 ng m⁻³ while the total metal concentration ranged from 5.6 to 28.6 μg m⁻³. The results showed that metals such as Cd, V and Ni are characterised by a MMD <1 μm, while the MMD for Pb and Mn are ∼1 μm. Such metals are generally considered to have anthropogenic emission sources. Other metals such as Al, Fe, Cu and Cr were found to have MMD=2–6 μm, which generally originate from soil dust or mechanical abrasion processes. The Carbon number profile of n-alkane compounds showed a strong anthropogenic source with only a minor biogenic influence. The concentration of most n-alkanes was characterised by high variability during the sampling period, in contrast to the concentration of most trace metals. Most n-alkanes had a unimodal size distribution with MMD=1–2 μm similar to those of some trace metals (Pb, Mn), which originate mostly from vehicle emissions. This is a strong indication that these species have a common source. Finally, gas–particle partitioning of n-alkanes was also examined for different particle sizes by means of the relationship between the partition constant K_p and saturation vapour pressure (p_L⁰) as proposed by current sorption models.     

Phytoremedial assessment of flora tolerant to heavy metals in the contaminated soils of an abandoned Pb mine in Central Portugal

Significant accumulation of heavy metals in soils and flora exists around the abandoned Barbadalhos Pb mine in Central Portugal. Soil and plant samples [49 species] were collected from two line transects, LT 1 and LT 2, in the mineralized and non-mineralized area, respectively to gain a comprehensive picture of heavy metals in soils and flora to assess its potential for phytoremediation. Phytosociological inventories of the vegetation were made using the Braun-Blanquet cover-abundance scale. Metal concentrations in soil ranged from (in mg kg^?1): 98–9330 [Pb], 110–517 [Zn], 7.1–50 [Co], 69–123 [Cr], 31–193 [Cu], 33 400–98 500 [Fe], 7.7–51 [Ni], 0.95–13 [Ag], 2.8–208 [As], and 71–2220 [Mn] along LT 1; and 24–93 [Pb], 30–162 [Zn], 3.7–34 [Co], 61–196 [Cr], 21–46 [Cu], 24 100–59 400 [Fe], 17–87 [Ni], 0.71–1.9 [Ag], 4.3–12 [As], and 44–1800 [Mn] along LT 2. Plant metal content ranged from (in mg kg^?1): 1.11–548 [Pb], 7.06–1020 [Zn], 0.08–2.09 [Co], 0.09–2.03 [Cr], 2.63–38.5 [Cu], 10.4–4450 [Fe], 0.38–8.9 [Ni], and 0.03–1.9 [Ag] along LT 1; and 0.94–11.58 [Pb], 2.83–96.5 [Zn], 0.12–1.44 [Co], 0.21–1.49 [Cr], 1.61–22.7 [Cu], 4.6–2050 [Fe], 0.51–4.81 [Ni], and 0.02–0.31 [Ag] along LT 2. Plants with highest uptake of metals were: Cistus salvifolius (548 mg Pb kg^?1), Digitalis purpurea (1017 mg Zn kg^?1 and 4450 mg Fe kg^?1). Mentha suavolens and Ruscus ulmifolius were seen to hyperaccumulate Ag (1.9 and 1 mg Ag kg^?1, respectively). More metals and higher concentrations were traced in plants from LT 1, especially for Pb and Zn.     

Spatial and seasonal variations of elemental composition in Mt. Everest (Qomolangma) snow/firn

In May 2005, a total of 14 surface snow (0–10 cm) samples were collected along the climbing route from the advanced base camp to the summit (6500–8844 m a.s.l.) on the northern slope of Mt. Everest (Qomolangma). A 108 m firn/ice core was retrieved from the col of the East Rongbuk Glacier (28.03°N, 86.96°E, 6518 m a.s.l.) on the north eastern saddle of Mt. Everest in September 2002. Surface snow and the upper 3.5 m firn samples from the core were analyzed for major and trace elements by inductively coupled plasma mass spectroscopy (ICP-MS). Measurements show that crustal elements dominated both surface snow and the firn core, suggesting that Everest snow chemistry is mainly influenced by crustal aerosols from local rock or prevalent spring dust storms over southern/central Asia.There are no clear trends for element variations with elevation due to local crustal aerosol inputs or redistribution of surface snow by strong winds during the spring. Seasonal variability in snow/firn elements show that high elemental concentrations occur during the non-monsoon season and low values during the monsoon season. Ca, Cr, Cs, and Sr display the most distinct seasonal variations. Elemental concentrations (especially for heavy metals) at Mt. Everest are comparable with polar sites, generally lower than in suburban areas, and far lower than in large cities. This indicates that anthropogenic activities and heavy metal pollution have little effect on the Mt. Everest atmospheric environment. Everest firn core REE concentrations are the first reported in the region and seem to be comparable with those measured in modern and Last Glacial Maximum snow/ice samples from Greenland and Antarctica, and with precipitation samples from Japan and the East China Sea. This suggests that REE concentrations measured at Everest are representative of the background atmospheric environment.     

Trace elements in aerosol and precipitation at New Castle,NH, USA

Concentrations of a suite of trace elements (Al, Ag, As, Cd, Co, Cr, Cu, Fe, Ni, Pb, Sr, V, Zn) were measured in aerosol and precipitation samples collected at a coastal site in New Castle, NH, from August 1996, through July 1997. Metal concentrations in aerosol and precipitation exhibit a high degree of temporal variability over the annual cycle, varying by approximately one order of magnitude or less for aerosol metals and by ∼2–3 orders of magnitude in precipitation. Estimates of the total annual atmospheric deposition of metals to the Gulf of Maine range from ∼10³ kg yr⁻¹ for Ag, ∼10⁴–10⁵ kg yr⁻¹ for the majority of metals, and ∼10⁶ kg yr⁻¹ for the crustal elements Al and Fe.     

Size distribution and anthropogenic sources apportionment of airborne trace metals in Kanazawa,Japan

Aerosol samples were collected from Kanazawa, Japan to examine the size distribution of 12 elements and to identify the major sources of anthropogenic elements. Key emission sources were identified and, concentrations contributed from individual sources were estimated as well. Concentrations of elements V, Ca, Cd, Fe, Ba, Mg, Mn, Pb, Sr, Zn, Co and Cu in aerosols were determined with ICP-MS. The results showed that Ca, Mg, Sr, Mn, Co and Fe were mainly associated with coarse particles (>2.1 μm), primarily from natural sources. In contrast, the elements Zn, Ba, Cd, V, Pb and Cu dominated in fine aerosol particles (<2.1 μm), implying that the anthropogenic origin is the dominant source. Results of the factor analysis on elements with high EF_Crust values (>10) showed that emissions from waste combustion in incinerators, oil combustion (involving waste oil burning and oil combustion in both incinerators and electricity generation plants), as well as coal combustion in electricity generation plants were major contributors of anthropogenic metals in the ambient atmosphere in Kanazawa. Quantitatively estimated sum of mean concentrations of anthropogenic elements from the key sources were in good agreement with the observed values. Results of this study elucidate the need for making pollution control strategy in this area.     

Comparison of the heavy metal bioaccumulation capacity of an epiphytic moss and an epiphytic lichen

This study compared the heavy metal bioaccumulation capacity in the epiphytic moss Scorpiurum circinatum and the epiphytic lichen Pseudevernia furfuracea, exposed in bags for 3 months in the urban area of Acerra (S Italy). The content of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Ti, V, and Zn was measured by ICP-MS. The results showed that both species accumulated all the heavy metals assayed. The moss had the highest bioaccumulation capacity for all metals and showed a more constant and linear accumulation trend than the lichen. Intra-tissue heavy metal bioaccumulation was assessed by X-ray microanalysis applied to ESEM operated in high and low vacuum and ESEM modes.     

Overall elemental dry deposition velocities measured around Lake Michigan

Overall dry deposition velocities of several elements were determined by dividing measured fluxes by measured airborne concentrations in different particle size ranges. The dry deposition measurements were made with a smooth surrogate surface on an automated dry deposition sampler (Eagle II) and the ambient particle concentrations were measured with a dichotomous sampler. These long-term measurements were made in Chicago, IL, South Haven, MI, and Sleeping Bear Dunes, MI, from December 1993 through October 1995 as part of the Lake Michigan Mass Balance Study. In general, the dry deposition fluxes of elements were highly correlated with coarse particle concentrations, slightly less well correlated with total particle concentrations, and least well correlated with fine particle concentrations. The calculated overall dry deposition velocities obtained using coarse particle concentrations varied from approximately 12 cm s⁻¹ for Mg in Chicago to 0.2 cm s⁻¹ for some primarily anthropogenic metals at the more remote sites. The velocities calculated using total particle concentrations were slightly lower. The crustal elements (Mg, Al, and Mn) had higher deposition velocities than anthropogenic elements (V, Cr, Cu, Zn, Mo, Ba and Pb). For crustal elements, overall dry deposition velocities were higher in Chicago than at the other sites.     

Correlation patterns of metals in the epiphytic moss Hypnum cupressiforme in Bavaria

Since 1981, the Bavarian State Office for Environmental Protection (LfU) has been operating a bioindication network of epiphytic mosses Hypnum cupressiforme located on a regular grid with distances 16 km, in order to observe immission-derived metal accumulation in plant material. About 300 specimens are collected yearly (since 1991 every second year) at the end of the growth period, and the concentration of trace metals is determined. In order to gain insight into predominant sources of metal pollution in Bavaria, correlation patterns between Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Sb, Hg, and Pb are analyzed by Principal Component Analysis. Detailed results are presented for the 1984 and 1995 data. At least 80% of the variance can be explained by five components. The following factors are extracted from both data sets by varimax rotation: factor 1 with similar loadings of Al, Ti, V, Cr, Fe, and As; factor 2 representing Cd and Zn; factor 3 with loadings of Sb, Pb, and Cu; factor 4 representing Mn; factor 5 being nearly identical with the Hg variable. For comparison, published region-specific correlation matrices from the 1991 moss survey performed by the German Federal Environmental Agency (UBA) – observing epigeic mosses Pleurozium schreberi – were submitted to Principal Component Analysis. With respect to the first factor, our 1991 results from Bavaria are similar to those from the Southern former GDR, but different from those from Western Germany (including Bavaria). Possible common and specific sources are discussed.     

Analysis of essential and non-essential trace elements in the organs of a mother–fetus pair of spotted seals (Phoca largha) from the Sea of Japan

Environmental Science and Pollution Research - Concentrations of 22 essential and non-essential trace elements (Be, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sb, Ba, Tl, Pb, Th, U, and...     

Elemental composition of aerosol in the Nam Co region,Tibetan Plateau,during summer monsoon season

In order to investigate the chemical characteristics of atmospheric aerosols in a remote region of the Tibetan Plateau, total suspended particles were collected continuously at the Nam Co Comprehensive Observation and Research Station from July to October 2005. The PIXE analytical results showed that Si, Ca, Fe, Al, K, and S were the major components of aerosols, ranging from 82 (K)–550 (Si) ng m⁻³. The mean elemental concentrations were comparable with those from other remote sites and significantly lower than those from megacities (e.g. Beijing). The very low presence of anthropogenic elements demonstrates that the Nam Co region is an ideal background site for atmospheric monitoring. Crustal enrichment factor (EF) calculation indicated that several anthropogenic heavy metals (Cr, Ni, Cu, Zn, As) are transported long distances atmospherically. The backward air mass trajectory analysis suggests that South Asia may be the source region of those pollutants.