Elemental uptake and distribution of nutrients in avocado mesocarp and the impact of soil quality

The distribution of 14 elements (both essential and non-essential) in the Hass and Fuerte cultivars of avocados grown at six different sites in KwaZulu-Natal, South Africa, was investigated. Soils from the different sites were concurrently analysed for elemental concentration (both total and exchangeable), pH, organic matter and cation exchange capacity. In both varieties of the fruit, concentrations of the elements Cd, Co, Cr, Pb and Se were extremely low with the other elements being in decreasing order of Mg > Ca > Fe > Al > Zn > Mn > Cu > Ni > As. Nutritionally, avocados were found to be a good dietary source of the micronutrients Cu and Mn. In soil, Pb concentrations indicated enrichment (positive geoaccumuluation indices) but this did not influence uptake of the metal by the plant. Statistical analysis was done to evaluate the impact of soil quality parameters on the nutrient composition of the fruits. This analysis indicated the prevalence of complex metal interactions at the soil–plant interface that influenced their uptake by the plant. However, the plant invariably controlled metal uptake according to metabolic needs as evidenced by their accumulation and exclusion.     

A study on chemical properties of groundwater and soil in ophiolitic rocks in Firuzabad, east of Shahrood, Iran: with emphasis to heavy metal contamination

In order to assess the chemical properties of groundwater and soil in ophiolitic zone of Firuzabad, in east of Shahrood, Iran, 10 soil samples with regard to sensitive points (vicinity to mine, ophiolitic rocks, and villages) and 10 groundwater samples including nine samples from springs, and also one sample from a well in a village of the study area were taken. These samples were analyzed in laboratories using inductively coupled plasma method. The soil samples were also evaluated for grain size. The obtained results show that most of heavy and major elements were exceeding the permissible levels in soil and water samples in the study area. On the subject of soil quality, concentrations of elements Cr, Mn, Fe, Ca, Mg, Ca, Ni, and Zn are above permissible levels. Enrichment factor and index of geoaccumulation have been calculated for heavy and major elements of all soil samples. According to the obtained results, it may be argued that soil samples are contaminated in relation to the above-mentioned indices. Comparing the concentrations of elements with results of grain size analysis illustrates that the concentrations of Cr, Ni, Fe, Mg, and Co are positively correlated with sand fraction and the concentrations of Al, P, Mn, and Pb are directly proportional with clay fraction in soil samples. The study on water contamination suggests that concentrations of elements Cr, Ni, and Mg in groundwater samples of the study area are above the permissible levels. Some indices like metal index and heavy metal pollution index show that most of the water samples include heavy metal contamination.     

Bacterial contamination in drinking water: a case study in rural areas of northern Rajasthan, India

Acid deposition has caused detrimental effects on tree growth near industrial areas of the world. Preliminary work has indicated that concentrations of NO(3-), SO(4)(2-), F( - ) and Al in soil solutions were 2 to 33 times higher in industrial areas compared to non-industrial areas in Korea. This study evaluated soil nutrient bioavailability and nutrient contents of red pine (Pinus thunbergii) needles in forest soils of industrial and non-industrial areas of Korea. Results confirm that forest soils of industrial areas have been acidified mainly by deposition of sulfate, resulting in increases of Al, Fe and Mn and decreases of Ca, Mg and K concentrations in soils and soil solutions. In soils of industrial areas, the molar ratios of Ca/Al and Mg/Al in forest soils were <2, which can lead to lower levels and availability of nutrients for tree growth. The Ca/Al molar ratio of Pinus thunbergii needles on non-industrial sites was 15, while that of industrial areas was 10. Magnesium concentrations in needles of Pinus thunbergii were lower in soils of industrial areas and the high levels of acid cations such as Al and Mn in these soils may have antagonized the uptake of base cations like Mg. Continued acidification can further reduce uptake of base cations by trees. Results show that Mg deficiency and high concentrations of Al and Mn in soil solution can be limiting factors for Pinus thunbergii growth in industrial areas of Korea.     

Factor analysis of essential and toxic elements in human placentas from deliveries in arctic and subarctic areas of Russia and Norway

Concentrations in human placenta of 11 essential elements (P, Ca, Mg, Cu, S, Na, Fe, Zn, K, Se, Mn) and 5 toxic elements (Ba, Sr, Pb, Ni, Cd) are compared for each of two arctic communities in eastern Norway and western Russia, and for another in each country located at more southerly latitudes. All but Mg, Fe, P and K were present in higher concentrations in the Russian study group. The observed inter-element correlations are reflected by the four major factors identified in a principal component analysis. The total variation explained was 67.3%, of which more than half (35.3%) was contributed by Factor 1. P, Ca, Mg, Ba, Sr, Pb, and Ni were major contributors to this factor. The placental concentrations of these elements depended strongly on gestational age, increasing from about week 35 and peaking near weeks 39 and 40, and exhibited skewed frequency distributions and a dependence on maternal smoking. The gestational-dependent mineralization of the placenta is interpreted to reflect the deposition of metal phosphates coinciding with smoking-induced tissue damage. The loadings of the remaining three factors are reviewed in the context of common uptake mechanisms, similar biochemistries and unique transport pathways. The inter-element relationships and grouping of the elements observed should constitute a scientific base for the use of placenta composition in environmental monitoring and epidemiological studies.     

Atmospheric deposition of major ions and trace metals near an industrial area,Jordan

Al, Cd, Cr, Cu, Fe, Mn, Pb, Zn, NH4+, Mg2+, Ca2+, Na+, K+, Cl-, NO3- and SO4(2-), along with pH were determined in wet and dry deposition samples collected at Al-Hashimya, Jordan. Mean trace metal concentrations were similar or less than those reported for other urban regions worldwide, while concentrations of Ca2+ and SO4(2-) were the highest. The high Ca2+ concentrations were attributed to the calcareous nature of the local soil and to the influence of the Saharan dust, while the high concentrations of SO4(2-) were attributed to the influence of anthropogenic sources and Saharan dust soil. Except for SO4(2-), NO3-, and Ca2+, dry deposition fluxes of measured metals and ions were higher than their corresponding wet deposition fluxes. The high annual average pH values recorded for wet and dry deposition samples were attributed to the neutralization of acidity by alkaline species. Cd, Cr, Cu, Pb, Zn, NO3- and SO4(2-) were enriched in wet and dry deposition samples relative to crustal material, and a significant anthropogenic contribution to these elements and ions is tentatively suggested. Finally, the possible sources and the main factors affecting the concentrations of the measured species are discussed.     

抚顺市PM10中元素分布特征及来源分析

为了确定抚顺市PM10中元素的浓度特征及其来源,于2006—2007年的采暖季、风沙季和非采暖季在抚顺市的6个采样点采集PM10样品,并用等离子体原子发射光谱法(ICP-AES)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。结果表明,Al、Mg、Ca、Na、K、Mn、Fe等地壳元素在17种元素中占有较大比重,全年平均达到97.0%。富集因子分析结果表明,Cu、Zn、Pb、Cr、Co、Cd等元素在各季和各采样点明显受到人为活动影响,是典型的污染元素。主因子分析结果显示,土壤风沙尘、建筑尘、燃煤尘、道路扬尘、机动车尾气排放、金属冶炼、锰、铜、钛工业源是抚顺市PM10中元素的主要来源。     

Assessment of radionuclide and metal contamination in a thorium rich area in Norway

The Fen Central Complex in southern Norway, a geologically well investigated area of magmatic carbonatite rocks, is assumed to be among the world largest natural reservoirs of thorium ((232)Th). These rocks, also rich in iron (Fe), niobium (Nb), uranium ((238)U) and rare earth elements (REE), were mined in several past centuries. Waste locations, giving rise to enhanced levels of both radionuclides and metals, are now situated in the area. Estimation of radionuclide and metal contamination of the environment and radiological risk assessment were done in this study. The average outdoor gamma dose rate measured in Fen, 2.71 μGy h(-1), was significantly higher than the world average dose rate of 0.059 μGy h(-1). The annual exposure dose from terrestrial gamma radiation, related to outdoor occupancy, was in the range 0.18-9.82 mSv. The total activity concentrations of (232)Th and (238)U in soil ranged from 69 to 6581 and from 49 to 130 Bq kg(-1), respectively. Enhanced concentrations were also identified for metals, arsenic (As), lead (Pb), chromium (Cr) and zinc (Zn), in the vicinity of former mining sites. Both radionuclide and heavy metal concentrations suggested leaching, mobilization and distribution from rocks into the soil. Correlation analysis indicated different origins for (232)Th and (238)U, but same or similar for (232)Th and metals As, Cr, Zn, nickel (Ni) and cadmium (Cd). The results from in situ size fractionation of water demonstrated radionuclides predominately present as colloids and low molecular mass (LMM) species, being potentially mobile and available for uptake in aquatic organisms of Norsj? Lake. Transfer factors, calculated for different plant species, showed the highest radionuclide accumulation in mosses and lichens. Uptake in trees was, as expected, lower. Relationship analysis of (232)Th and (238)U concentrations in moss and soil samples showed a significant positive linear correlation.     

Mobilization of metals and phosphorus from intact forest soil cores by dissolved inorganic carbon

Increased dissolved inorganic carbon (DIC) enhances the mobilization of metals and nutrients in soil solutions. Our objective was to investigate the mobilization of Al, Ca, Fe, and P in forest soils due to fluctuating DIC concentrations. Intact soil cores were taken from the O and B horizons at the Bear Brook Watershed in Maine (BBWM) to conduct soil column transport experiments. Solutions with DIC concentrations (～20–600 ppm) were introduced into the columns. DIC was reversibly sorbed and its migration was retarded by a factor of 1.2 to 2.1 compared to the conservative sodium bromide tracer, corresponding to a log K _D?=???0.82 to ?0.07. Elevated DIC significantly enhanced the mobilization of all Al, Fe, Ca, and P. Particulate (>0.4 μm) Al and Fe were mobilized during chemical and flow transitions, such as increasing DIC and dissolved organic carbon (DOC), and resumption of flow after draining the columns. Calcium and P were primarily in dissolved forms. Mechanisms such as ion exchange (Al, Fe, Ca), ligand- and proton-promoted dissolution (Al and Fe), and ligand exchange (P) were the likely chemical mechanisms for the mobilization of these species. One column was packed with dried and sieved B-horizon soil. The effluent from this column had DOC, Al, and Fe concentrations considerably higher than those in the intact columns, suggesting that these species were mobilized from soil’s microporous structure that was otherwise not exposed to the advective flow. Calcium and P concentrations, however, were similar to those in the intact columns, suggesting that these elements were less occluded in soil particles.     

Vertical gradients of mineral elements in Pinus sylvestris crown in alkalised soil

Alkalisation of soil has been assumed to be the principal cause of changes in vertical gradients of nutrients in Pinus sylvestris crown. The long-term influence of alkaline dust pollution ( ${\rm {pH}}_{{\rm H}_{2}{\rm O}}$  12.3–12.6) emitted from a cement plant on the element composition of soil and needles of Scots pine in different canopy layers was studied. In the polluted area, the pH of soils was >7, and high amounts of Ca, K and Mg were measured in the upper layers of soil (0–30 cm), while the mobility and solubility of some contaminants have decreased, nutrition processes have become complicated, and imbalance of mineral composition of trees was revealed. Reduced N and increased K, Ca and Mg concentrations in needles were observed in the heavily polluted area. Vertical gradients of elements and their ratios in canopies varied depending on the alkalisation level of soil. Needles on the upper-crown shoots had higher concentrations of N, C, Ca and Mg and lower concentrations of P and K compared to the lower layer of the crown. In the unpolluted area, higher concentrations of N, P, K and Ca were found in lower-crown needles and of C and Mg in needles at the top of the canopy. The P/N ratio below 0.125 indicated P deficiency in pines. The ratios N/Ca, N/Mg and N/K had significantly decreased, while the ratios Ca/Mg, K/Mg and K/Ca had a tendency to increase in heavily polluted sample plots. Magnitude of changes of element ratios indicates on the disbalances of availability and translocation of nutrients in the crown of trees.     

Foliar concentrations of volunteer willows growing on polluted sediment-derived sites versus sites with baseline contamination levels

Many alluvial soils along navigable waterways are affected by disposal of dredged sediments or overbank sedimentation and contain metal concentrations that are elevated compared to baseline levels. Uptake patterns for metals and other elements by several volunteer Salix species growing on these sites were determined during a growing season in field plots and compared with the same species growing on soils with baseline contamination levels. For Cd and Zn, foliar concentrations were clearly higher on dredged sediment landfills. Uptake patterns differed significantly between species. A high uptake of Mn and low uptake of Cu, K and S in S. cinerea was attributed to wetland soil chemistry. Site effects on metal uptake were evaluated in more detail for Salix cinerea and S. alba growing on different sediment-derived sites under field conditions. Foliar Cd concentrations were higher in S. cinerea than in S. alba. This appeared to be a genetic feature not influenced by soil chemical properties, as it was observed both on clean sites and polluted sediment-derived sites. For S. cinerea, soil chemistry was reflected in foliar concentrations, while foliar Cd concentrations and bioavailability were found to be independent of the thickness of the polluted horizon. Dredged sediment landfills and freshwater tidal marshes with comparable Cd soil pollution had significantly different foliar Cd concentrations.     

Red sea corals as biomonitors of trace metal pollution

Red Sea corals have been found to be biomonitors of trace metal pollution. A comparative study was undertaken on three species from a polluted area near a desalination plant at Jeddah (Saudi Arabia) and from an unpolluted area. The results show that corals take-up trace elements from their aquatic environment and thereby act to record changes in the composition of that environment. Variations in the composition of skeletons and soft tissues of corals have been correlated with changes in sea water composition. Three coral species, Porites lutea, Goniastrea retiformis and Pocillopora verrucosa have been analysed for Hg, Cu, Zn, Pb, Mn, Fe, Ni, Cd, V, Al, Cr, Mg, B, Ca, and Sr in both skeletal and soft tissues. Results show that corals in the polluted areas have significantly higher concentrations of trace elements compared to that of corals from unpolluted areas.     

Acid soil indicators in forest soils of the Cherry River Watershed, West Virginia

Declining forest health has been observed during the past several decades in several areas of the eastern USA, and some of this decline is attributed to acid deposition. Decreases in soil pH and increases in soil acidity are indicators of potential impacts on tree growth due to acid inputs and Al toxicity. The Cherry River watershed, which lies within the Monongahela National Forest in West Virginia, has some of the highest rates of acid deposition in Appalachia. East and West areas within the watershed, which showed differences in precipitation, stream chemistry, and vegetation composition, were compared to evaluate soil acidity conditions and to assess their degree of risk on tree growth. Thirty-one soil pits in the West area and 36 pits in the East area were dug and described, and soil samples from each horizon were analyzed for chemical parameters. In A horizons, East area soils averaged 3.7 pH with 9.4 cmol_c kg^???1 of acidity compared to pH 4.0 and 6.2 cmol_c kg^???1 of acidity in West area soils. Extractable cations (Ca, Mg, and Al) were significantly higher in the A, transition, and upper B horizons of East versus West soils. However, even with differences in cation concentrations, Ca/Al molar ratios were similar for East and West soils. For both sites using the Ca/Al ratio, a 50% risk of impaired tree growth was found for A horizons, while a 75% risk was found for deeper horizons. Low concentrations of base cations and high extractable Al in these soils translate into a high degree of risk for forest regeneration and tree growth after conventional tree harvesting.     

Geochemical patterns in soils in and around Siddipet, Medak District, Andhra Pradesh, India

This paper reports the first results of geochemical survey carried out in and around Siddipet, taking soil (topsoil 0–25 cm and subsoil 70–95 cm) as the sampling media. The data were obtained in a consistent way from 61 sites. The samples were analyzed for 29 elements (As, Ba, Cd, Co, Cr, Cu, F, Mo, Ni, Pb, Rb, Se, Sr, Th, U, V, Y, Zn, Zr, Si, Al, Fe, Mn, Mg, Ca, Na, K, Ti, and P) by X-ray fluorescence spectrometer, and baseline levels for these elements are presented. Results reveal that the correlation between the geochemical patterns in the soils developed on different litho-variants is not straight forward, but some general trends can be observed. Regional parent materials and pedogenesis are the primary factors influencing the concentrations of trace elements while anthropogenic activities have secondary influence.     

The relationship between chemical elements in soil and whole blood,and fluorosis induced by coal-fired pollution

To study the relationship between chemical elements in soil and whole blood, and fluorosis induced by coal-fired pollution, ecological and case–control studies were carried out. We determined the concentrations of 11 chemical elements and pH values in soil in two fluorosis-affected counties in Chongqing, China, and analyzed the correlation between these values and prevalence of dental fluorosis. Ni, I, F, Hg, and pH values positively correlated with fluorosis prevalence (P?<?0.05); these soil parameters may be related to coal-fired pollution fluorosis. Cu, Zn, Ca, Mg, and Fe concentrations in whole blood, and fluoride levels in urine of residents in epidemic and non-epidemic areas were determined. Cu, Zn, Mg, and Fe levels of the children in the case group were lower than those of the children in the external control group; urine fluoride level in the children in the case group was higher than that of the children in the internal and external control groups (P?<?0.05). The levels of Mg, Fe, and urine fluoride were higher in the case adult group than in the internal adult control group (P?<?0.05). Anti-fluoride elements were deficient in endemic areas.     

Assessment of background levels of trace metals in water and soil from a remote region of Himalaya

Selected trace metals were estimated by atomic absorption spectrometry in the water and soil samples collected from the remote region of Himalaya. The soil samples were analysed for soluble and acid extractable fraction of trace metals. In water samples, Ca, Na, Mg and K emerged as dominant contributors, whereas, Ca, Na, K, Mg, Fe and Pb were estimated at comparatively higher levels in the water extract of the soil. In case of acid extract of the soil samples, Ca, K, Fe, Mg, Mn and Na were found at elevated concentrations. Based on mean levels of the metals, following decreasing concentration order was observed in water samples: Ca > Na > Mg > K > Pb > Co > Cu > Zn > Mn > Cr > Fe > Cd > Li, however, in the acid extract of the soil, following order was noted: Ca > K > Fe > Mg > Mn > Na > Pb > Zn > Cr > Li > Cu > Co > Cd. The correlation study revealed appreciably diverse mutual relationships of trace metals in the water and soil samples. The multivariate cluster analyses exhibited divergent apportionment of trace metals in water and soil samples. Among the trace metals, Cd, Pb, Li, Zn, Cr, Cu, Mn and Co exhibited extreme to significant anthropogenic enrichment in the soil samples, while the rest of the metals were mostly contributed by the natural processes.     

Soil response to a 3-year increase in temperature and nitrogen deposition measured in a mature boreal forest using ion-exchange membranes

The projected increase in atmospheric N deposition and air/soil temperature will likely affect soil nutrient dynamics in boreal ecosystems. The potential effects of these changes on soil ion fluxes were studied in a mature balsam fir stand (Abies balsamea [L.] Mill) in Quebec, Canada that was subjected to 3 years of experimentally increased soil temperature (+4 °C) and increased inorganic N concentration in artificial precipitation (three times the current N concentrations using NH₄NO₃). Soil element fluxes (NO₃, NH₄, PO₄, K, Ca, Mg, SO₄, Al, and Fe) in the organic and upper mineral horizons were monitored using buried ion-exchange membranes (PRS? probes). While N additions did not affect soil element fluxes, 3 years of soil warming increased the cumulative fluxes of K, Mg, and SO₄ in the forest floor by 43, 44, and 79 %, respectively, and Mg, SO₄, and Al in the mineral horizon by 29, 66, and 23 %, respectively. We attribute these changes to increased rates of soil organic matter decomposition. Significant interactions of the heating treatment with time were observed for most elements although no clear seasonal patterns emerged. The increase in soil K and Mg in heated plots resulted in a significant but small K increase in balsam fir foliage while no change was observed for Mg. A 6–15 % decrease in foliar Ca content with soil warming could be related to the increase in soil-available Al in heated plots, as Al can interfere with the root uptake of Ca.     

Availability of geogenic heavy metals in soils of Thiva town (central Greece)

Potentially toxic metals in the urban chemical environment impose risks to both ecosystem and human health. Here, we evaluate the labile pools and availabilities of non-anthropogenic Ni, Cr, Co and Mn in soil samples from Thiva town (central Greece) and investigate their associations with common soil properties and geochemical data obtained by the aqua regia and single selective dissolutions. Experimental work included the initial application of the sequential extraction protocol proposed by the European Community Bureau of Reference and chemical extractions with ethylenediamine tetraacetic acid solution and a modified physiologically based extraction test with the aim to obtain the operationally defined fractions of plant availability and human bioaccessibility, respectively. The leachate results demonstrated that despite the significant contribution of residual metal species especially for Ni and Cr, the studied serpentine soils provide chemically labile pools for all the considered elements. Nickel was found to be the most available metal with the order being Ni?>?Cr?～?Co?～?Mn for plant uptake and Ni?>?Cr?>?Co?～?Mn for human bioaccessibility. The aqua regia extractable concentrations are not predictors of elemental availabilities except for Ni bioaccessible data interpreting however only a moderate percentage of the total variance. The incorporation of basic soil properties (mostly total organic carbon), geochemical data for the major elements Ca, Mg and Fe and ammonium oxalate extractable Cr significantly improved the estimations for individual elements entailing the strong influence of the chemistry and mineralogy of soil materials to the release of focus metals from the soil matrix. This study provides for the first time bioaccessible data for serpentine-derived soils that are more realistic for evaluating potential adverse effects on the human health.     

Introduction of the Factor of Partitioning in the Lithogenic Enrichment Factors of Trace Element Bioaccumulation in Plant Tissues

Bioindicators are widely used in the study of trace elements inputs into the environment and great efforts have been conducted to separate atmospheric from soil borne inputs on biomass accumulation. Many monitoring studies of trace element pollution take into account the dust particles located in the plant surface plus the contents of the plant tissues. However, it is usually only the trace element content in the plant tissues that is relevant on plant health. Enrichment factor equations take into account the trace element enrichment of biomasses with respect soil or bedrocks by comparing the ratios of the trace element in question to a lithogenic element, usually Al. However, the enrichment equations currently in use are inadequate because they do not take into account the fact that Al (or whichever reference element) and the element in question may have different solubility-absorption-retention levels depending on the rock and soil types involved. This constrain will become critical when results from different sites are compared and so in this article we propose that the solubility factors of each element are taken into account in order to overcome this constrain. We analysed Sb, Co, Ni, Cr, Pb, Cd, Mn, V, Zn, Cu, As, Hg, and Al concentration in different zones of Catalonia (NE Spain) using the evergreen oak Quercus ilex and the moss Hypnum cupressiforme as target species. We compared the results obtained in rural and non industrial areas with those from the Barcelona Metropolitan Area. We observed differences in Al concentrations of soils and bedrocks at each different site, together with the differences in solubility between Al and the element in question, and a weak correlation between total soil content and water extract content through different sites for most trace elements. All these findings show the unsuitability of the current enrichment factors for calculating lithospheric and atmospheric contributions to trace element concentrations in biomass tissues. The trace element enrichment factors were calculated by subtracting the part predicted by substrate composition (deduced from water extracts from soils and bedrock) from total concentrations. Results showed that for most of the trace elements analysed, trace elements enrichment factors were higher inside the Barcelona Metropolitan Area than outside, a finding that indicates that greater atmospheric inputs occur in urban areas. The results show that the most useful and correct way of establishing a reference for lithospheric and atmospheric inputs into the plant tissues is, first, to analyse samples of the same plant species collected from a number of sites possessing similar environmental conditions (climate, vegetation type, soil type) and, second, to use this new enrichment factor obtained by subtracting from the total concentration in plant tissue the predicted contribution of soil or bedrock extracts instead of that of total soil or bedrock concentrations.     

Biogenic and toxic elements in feathers, eggs, and excreta of Gentoo penguin (Pygoscelis papua ellsworthii) in the Antarctic

Feathers, eggs, and excreta of Gentoo penguin (Pygoscelis papua ellsworthii), adults, from Livingston Island (South Shetlands), chosen as bioindicators, were used to test the quality of the Antarctic environment. Sex was not examined. The bioaccumulations of toxic trace elements (Cd, Pb, Al, and As), essential trace elements (Fe, Cu, Zn, Mn, Cr, V, Ni, and Sr), and major essential elements (Na, K, Mg, Ca, P, and S) were established. For the first time data about the element contents in Gentoo eggs is provided. Two hypotheses were tested: (1) there are differences in the metal levels among eggs and feathers; and (2) the element concentrations are highest in the excreta. The hypotheses were confirmed at 0.01-0.05 confidence levels. The concentrations of almost all trace elements were significantly higher in the feathers compared to those in the eggs. The following values of the concentrations ratio Fe/Zn were obtained: in the embryo, Fe/Zn = 1.5, and in the feathers, Fe/Zn = 0.5. The concentration of Pb in the embryo and excreta was below 0.4 μg/g, and Cd and As in eggs were below 0.05 and 0.3 μg/g, respectively. This indicates that there is no toxic risk for penguin offspring. Arsenic could be considered as a potential pollutant for Antarctic soil due to its relative high concentration in excreta, 5.13 μg/g. The present data (year 2007) were compared to the data for years 2002 and 2003. No trend of toxic element contamination was established. The concentrations of Pb, Cd, and As in representatives from the top of the food chain in the Antarctic (the present study) and Arctic (literature data) were compared. The data supports the hypothesis that there is an abnormality in cadmium levels in polar marine areas. Regarding Pb, the South Shetlands displayed 3-fold lower level compared to the Aleutians.     

A historical study of mineral elements in forest plants from South Norway

Herbarium plants were used as a material to study possible long-term changes in mineral elements of forest plants. Plants from South Norway collected in the period 1870 to 1930 were compared to plants collected in 1982. Relative to mineral contents in plants from 1870 to 1930, the 1982 material showed elevated levels of Zn, Cd, Rb, K, Mn and Ti and decreased levels of Sr, B, Ca and Mo in some of the plant species analysed. Most of these differences may be explained by changes in the environmental conditions, due to differences in chemical composition of precipitation, accelerated soil acidification and subsequent increasing mineral weathering. Consequently analysis of herbarium plants seems to provide valuable information about preindustrial levels of mineral elements and seems to detect changes in mineral elements brought about by recent anthropogenic activity.