Biomonitoring with epiphytic lichens as a complementary method for the study of mercury contamination near a cement plant.

The study was focused on understanding the mercury contamination caused by a cement plant. Active and passive biomonitoring with epiphytic lichens was combined with other instrumental measurements of mercury emissions, mercury concentrations in raw materials, elemental mercury concentrations in air, quantities of dust deposits, temperatures, precipitation and other measurements from the cement plant's regular monitoring programme. Active biomonitoring with transplanted lichens Pseudevernia furfuracea (L.) Zopf was performed at seven of the most representative sites around the cement plant and one distant reference site for periods of 3, 6 and 12 months. In situ lichens of different species were collected at the beginning of the monitoring period at the same sites. Mercury speciation of the plant exhaust gas showed that the main form of emitted mercury is reactive gaseous mercury Hg²âº, which is specific for cement plants. Elemental mercury in air was measured in different meteorological conditions using a portable mercury detector. Concentrations in air were relatively low (on average below 10 ng m⁻³). In situ lichens showed Hg concentrations comparable to lichens taken from the background area for transplantation, indicating that the local pollution is not severe. Transplanted lichens showed an increase of mercury, especially at one site near the cement plant. A correlation between precipitation and Hg uptake was not found probably due to a rather uniform rainfall in individual periods. Dust deposits did not influence Hg uptake significantly. Lichens vitality was affected over longer biomonitoring periods, probably due to some elements in dust particles, their alkalinity and the influence of other emissions. Mercury uptake measured in vital transplanted lichens was in a good correlation with the working hours (i.e. emitted Hg quantity) of the kiln. The study showed that selected lichens could be used to detect low to moderate Hg emissions from a cement plant and that the biomonitoring procedure could be further standardized and used as part of an environmental monitoring programme.

Arsenic accumulation and thiol status in lichens exposed to As(V) in controlled conditions.

Thalli of epiphytic lichen Hypogymnia physodes (L.) Nyl. and terricolous Cladonia furcata (Huds.) Schrad., collected from an area with background arsenic concentrations, were exposed to 0, 0.1, 1 and 10 microg mL(-1) arsenate (As(V)) solutions for 24 h. After exposure they were kept in the metabolically active state for 0, 24 and 48 h in a growth chamber. In the freeze dried samples glutathione (GSH), glutathione disulphide (GSSG), cysteine (Cys) and cystine were analysed and induction of phytochelatin (PC) synthesis measured by reversed-phase high-performance liquid chromatography in combination with fluorescence detection or UV spectrometry. Total arsenic content in thalli was measured by instrumental neutron activation analysis (INAA). In H. physodes, which contained higher amounts of arsenic compared to C. furcata, total glutathione content significantly decreased in samples exposed to 10 microg mL(-1) As(V), whereas in C. furcata a significant increase was observed. In both species PC synthesis was induced in thalli exposed to 10 microg mL(-1).

Results of the first national human biomonitoring in Slovenia: Trace elements in men and lactating women, predictors of exposure and reference values.

The first national human biomonitoring in Slovenia surveyed cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), manganese (Mn), selenium (Se), copper (Cu) and zinc (Zn) in a childbearing population (18-49 years) selected from lactating primiparous women and men (N = 1084). The overall aim was to estimate trace elements' levels and geographical variations in order to identify sources of possible exposures and set the national reference values. The study population was selected evenly from 12 study areas across Slovenia, including rural, urban and known or potentially contaminated environments. Within 6-8 weeks after delivery, venous blood, spot urine, scalp hair and breast milk samples were collected to determine the selected elements. The data analysis included descriptive statistics and multiple linear regression using elemental concentrations in biological matrices, questionnaire data and environmental datasets. Essential elements showed no significant deficiencies or excessive levels in the study population and were largely determined by sex and/or the participating women's physiological status (postpartum, lactation), as well as by certain dietary sources. Toxic elements' levels were mainly below the levels considered to present increased health risk. Lifestyle and nutritional habits appeared as significant determinants of exposure to Cd (smoking and game meat consumption), Hg (seafood and amalgam fillings), As (seafood) and Pb (alcohol consumption, smoking, game meat consumption and type of water supply). A distinctive geographical pattern was confirmed, due to past mining activities combined with naturally elevated background levels in the cases of Pb (Mezica Valley), Hg (Idrija and Posocje) and As exposure (Zasavje). Increased seafood consumption in the coastal study area contributed to higher Hg and As (arsenobetaine) levels. Extensive sample size database accompanied with life-style and environmental data improved the prediction of exposure patterns, set the reference values for the childbearing population living in Slovenia, and provided a strong basis for evaluating spatial and temporal trends in exposure. To our best knowledge, this is the first study to establish reference values for lactating primiparous women.

Uptake and biotransformation of arsenate in the lichen Hypogymnia physodes (L.) Nyl.

The uptake and metabolism of arsenate, As(V), as a function of time and concentration were examined in the lichen Hypogymnia physodes (L.) Nyl. Lichen thalli were exposed to As(V) in the form of a solution. Exponential uptake of As(V) from 4 microg mL(-1) As(V) solution was accompanied by constant arsenite, As(III), excretion back into the solution. Arsenate taken up into the lichens from 0, 0.1, 1, 10 microg mL(-1) As(V) solutions was partially transformed into As(III), dimethylarsinic acid (DMA) and (mono)methylarsonic acid (MA). 48 h after exposure, the main arsenic compound in the lichens was DMA in 0.1, As(III) in 1 and As(V) in 10 microg mL(-1) treatment. The proportion of methylated arsenic compounds decreased with increasing arsenate concentration in the exposure solution. These results suggest that at least two types of As(V) detoxification exist in lichens; arsenite excretion and methylation.

Metal accumulation in mosses across national boundaries: uncovering and ranking causes of spatial variation.

This study aimed at cross-border mapping metal loads in mosses in eight European countries in 1990, 1995, and 2000 and at investigating confounding factors. Geostatistics was used for mapping, indicating high local variances but clear spatial autocorrelations. Inference statistics identified differences of metal concentrations in mosses on both sides of the national borders. However, geostatistical analyses did not ascertain discontinuities of metal concentrations in mosses at national borders due to sample analysis in different laboratories applying a range of analytical techniques. Applying Classification and Regression Trees (CART) to the German moss data as an example, the local variation in metal concentrations in mosses were proved to depend mostly on different moss species, potential local emission sources, canopy drip and precipitation.

Estimation of uncertainty arising from different soil sampling devices: the use of variogram parameters.

In the frame of the international SOILSAMP project, funded and coordinated by the National Environmental Protection Agency of Italy (APAT), uncertainties due to field soil sampling were assessed. Three different sampling devices were applied in an agricultural area using the same sampling protocol. Cr, Sc and Zn mass fractions in the collected soil samples were measured by k(0)-instrumental neutron activation analysis (k(0)-INAA). For each element-device combination the experimental variograms were calculated using geostatistical tools. The variogram parameters were used to estimate the standard uncertainty arising from sampling. The sampling component represents the dominant contribution of the measurement uncertainty with a sampling uncertainty to measurement uncertainty ratio ranging between 0.6 and 0.9. The approach based on the use of variogram parameters leads to uncertainty values of the sampling component in agreement with those estimated by replicate sampling approach.

A soil sampling reference site: the challenge in defining reference material for sampling.

In the frame of the international SOILSAMP project, funded and coordinated by the Italian Environmental Protection Agency, an agricultural area was established as a reference site suitable for performing soil sampling inter-comparison exercises. The reference site was characterized for trace element content in soil, in terms of the spatial and temporal variability of their mass fraction. Considering that the behaviour of long-lived radionuclides in soil can be expected to be similar to that of some stable trace elements and that the distribution of these trace elements in soil can simulate the distribution of radionuclides, the reference site characterised in term of trace elements, can be also used to compare the soil sampling strategies developed for radionuclide investigations.

The effect of short-range spatial variability on soil sampling uncertainty.

This paper aims to quantify the soil sampling uncertainty arising from the short-range spatial variability of elemental concentrations in the topsoils of agricultural, semi-natural, and contaminated environments. For the agricultural site, the relative standard sampling uncertainty ranges between 1% and 5.5%. For the semi-natural area, the sampling uncertainties are 2-4 times larger than in the agricultural area. The contaminated site exhibited significant short-range spatial variability in elemental composition, which resulted in sampling uncertainties of 20-30%.

Modelling spatial patterns of correlations between concentrations of heavy metals in mosses and atmospheric deposition in 2010 across Europe.

BACKGROUND: This paper aims to investigate the correlations between the concentrations of nine heavy metals in moss and atmospheric deposition within ecological land classes covering Europe. Additionally, it is examined to what extent the statistical relations are affected by the land use around the moss sampling sites. Based on moss data collected in 2010/2011 throughout Europe and data on total atmospheric deposition modelled by two chemical transport models (EMEP MSC-E, LOTOS-EUROS), correlation coefficients between concentrations of heavy metals in moss and in modelled atmospheric deposition were specified for spatial subsamples defined by ecological land classes of Europe (ELCE) as a spatial reference system. Linear discriminant analysis (LDA) and logistic regression (LR) were then used to separate moss sampling sites regarding their contribution to the strength of correlation considering the areal percentage of urban, agricultural and forestry land use around the sampling location. After verification LDA models by LR, LDA models were used to transform spatial information on the land use to maps of potential correlation levels, applicable for future network planning in the European Moss Survey. RESULTS: Correlations between concentrations of heavy metals in moss and in modelled atmospheric deposition were found to be specific for elements and ELCE units. Land use around the sampling sites mainly influences the correlation level. Small radiuses around the sampling sites examined (5 km) are more relevant for Cd, Cu, Ni, and Zn, while the areal percentage of urban and agricultural land use within large radiuses (75-100 km) is more relevant for As, Cr, Hg, Pb, and V. Most valid LDA models pattern with error rates of < 40% were found for As, Cr, Cu, Hg, Pb, and V. Land use-dependent predictions of spatial patterns split up Europe into investigation areas revealing potentially high (= above-average) or low (= below-average) correlation coefficients. CONCLUSIONS: LDA is an eligible method identifying and ranking boundary conditions of correlations between atmospheric deposition and respective concentrations of heavy metals in moss and related mapping considering the influence of the land use around moss sampling sites.

Accumulation of 210Po in coastal waters (Gulf of Trieste, northern Adriatic Sea).

The total activity of 210Po was determined by alpha-spectrometry in various samples (matrices) collected in the Gulf of Trieste (northern Adriatic Sea) where fresh water inflows, especially from the Isonzo River in the northern part, affect water quality. Observed 210Po levels were: 1) 0.56-3.75 mBq/L in the dissolved phase (<0.45 µm) in the seawater column and local rivers, 2) 0.35-3.11 mBq/L (400-2300 Bq/kg, dry weight, dw) in suspended particulate matter (SPM, 0.45-20 µm) in the seawater column and local rivers, 3) 40 (Isonzo River) -158 Bq/kg (in a surface sediment cores collected in a NS transect in the gulf and sectioned to the depth of 20 cm) and 4) 239 (autumn) - 415 to 1800 (spring) Bq/kg (dw) in meso(zoo)plankton (>200 µm). In seawater and tributaries, up to 80% (mean 49%) of total 210Po was found in particulate form. In sediments, slightly higher levels were encountered in the Isonzo prodelta and in the central (depocenter) part of the gulf. KD (L/kg) calculated between seawater and SPM, and seawater and sediment amounted to about 5 × 106 and 6 × 104, respectively. Lower autumn 210Po levels can be a consequence of biological dilution by higher mesozooplankton biomass in the autumn compared to spring. Plankton fractionation revealed in general the highest levels in the >200 µm mesoplankton fraction (239-1800 Bq/kg) followed by 50-200 µm (388-996 Bq/kg) and 20-50 µm (318-810 Bq/kg) microplankton fractions. Obtained data show higher 210Po levels in all matrices analyzed in the Gulf of Trieste compared to other Adriatic (central Adriatic) and western Mediterranean areas. The 210Po/210Pb ratios in water, plankton and sediments were mostly below or around 1, while this ratio was much higher at higher trophic levels (up to about 50), reflecting a preferential bioaccumulation of 210Po over 210Pb. 210Po accumulation between seawater and SPM and seawater and mesozooplankton amounted to 3.7 × 104 and 1.1 × 104, respectively, similar to other Adriatic areas. Comparison of the relative importance of pelagic and benthic bioaccumulation pathways, excluding the filter feeder bivalves, suggests greater accumulation in pelagic-feeding species.

Radon in soil gas in Kosovo.

An assessment of the radiological situation due to exposure to radon and gamma emitting radionuclides was conducted in southern Kosovo. This study deals with sources of radon in soil gas. A long-term study of radon concentrations in the soil gas was carried out using the SSNTDs (CR-39) at 21 different locations in the Sharr-Korabi zone. The detectors were exposed for an extended period of time, including at least three seasonal periods in a year and the sampling locations were chosen with respect to lithology. In order to determine the concentration of the natural radioactive elements 238U and 226Ra, as a precursor of 222Rn, soil samples were collected from each measuring point from a depth of 0.8 m, and measured by gamma spectrometry. The levels (Bq kg-1) of naturally occurring radionuclides and levels (kBq m-3) of radon in soil gas obtained at a depth 0.8 m of soil were: 21-53 for 226Ra, 22-160 for 238U and 0.295-32 for 222Rn. With respect to lithology, the highest value for 238U and 226Ra were found in limestone and the highest value for 222Rn was found in metamorphic rocks. In addition, the results showed seasonal variations of the measured soil gas radon concentrations with maximum concentration in the spring months.

Radioactivity of cigarettes and the importance of (210)Po and thorium isotopes for radiation dose assessment due to smoking.

Tobacco and tobacco smoke are very complex mixtures. In addition to various chemical and organic compounds they also contain natural radioactive elements (radionuclides). In this work, the natural radionuclide activity concentrations ((234)U, (238)U, (228)Th, (230)Th, (232)Th, (226)Ra, (210)Pb and (210)Po) of nine different cigarette samples available on the Slovenian market are reported. In addition to (210)Po, the transfer of thorium isotopes from a cigarette to a smoker's body and lungs have been determined for the first time. Cigarette smoke and exhaled air from smokers' lungs were collected from volunteer smokers (C-4 brand) to determinate what quantity of (210)Po and thorium isotopes is transferred from the tobacco to the smoker's lungs. Cigarette ash and smoked filters were also collected and analysed. Among the determined isotopes, (210)Pb and (210)Po showed the highest activity concentrations. During the smoking of one cigarette approximately 22% of (210)Po (and presumably its predecessor (210)Pb), 0.6% of (228)Th, 24% of (230)Th, and 31% of (232)Th are transferred from the cigarette and retained in the smoker's body. The estimated annual effective dose for smokers is 61 µSv/year from (210)Po; 9 µSv/year from (210)Pb; 6 µSv/year from (228)Th; 47 µSv/year from (230)Th, and 37 µSv/year from (232)Th. These results show the importance of thorium isotopes in contributing to the annual effective dose for smoking.

Spatially valid data of atmospheric deposition of heavy metals and nitrogen derived by moss surveys for pollution risk assessments of ecosystems.

For analysing element input into ecosystems and associated risks due to atmospheric deposition, element concentrations in moss provide complementary and time-integrated data at high spatial resolution every 5 years since 1990. The paper reviews (1) minimum sample sizes needed for reliable, statistical estimation of mean values at four different spatial scales (European and national level as well as landscape-specific level covering Europe and single countries); (2) trends of heavy metal (HM) and nitrogen (N) concentrations in moss in Europe (1990-2010); (3) correlations between concentrations of HM in moss and soil specimens collected across Norway (1990-2010); and (4) canopy drip-induced site-specific variation of N concentration in moss sampled in seven European countries (1990-2013). While the minimum sample sizes on the European and national level were achieved without exception, for some ecological land classes and elements, the coverage with sampling sites should be improved. The decline in emission and subsequent atmospheric deposition of HM across Europe has resulted in decreasing HM concentrations in moss between 1990 and 2010. In contrast, hardly any changes were observed for N in moss between 2005, when N was included into the survey for the first time, and 2010. In Norway, both, the moss and the soil survey data sets, were correlated, indicating a decrease of HM concentrations in moss and soil. At the site level, the average N deposition inside of forests was almost three times higher than the average N deposition outside of forests.

Potential environmental factors that influence the nitrogen concentration and δ(15)N values in the moss Hypnum cupressiforme collected inside and outside canopy drip lines.

Samples of the moss Hypnum cupressiforme were collected at 103 locations in forests of Slovenia. At each location, samples were taken at two types of sites: under tree canopies and in adjacent forest openings. The results show that the moss collected in the forest openings reflects the surrounding land-use characteristics and, consequently, the main N emission sources. For moss sampled under canopies, the characteristics of the forest at the moss-sampling locations are more important than the main emission sources outside the forest. A regression model was used to provide the nitrogen (N) concentration in moss from the forest openings in relation to the N concentration in moss under canopies and other environmental variables. The spatial distribution of the locations of the N concentrations and δ(15)N values in moss collected in the forest openings and under the canopies in relation to main N deposition sources is discussed.

Influence of canopy drip on the indicative N, S and δ(15)N content in moss Hypnum cupressiforme.

Samples of Hypnum cupressiforme were collected at two types of site in forest areas: within the forest stand and within forest openings, and analyzed for N and S concentrations and δ(15)N. Mosses sampled within forest openings reflect the atmospheric N deposition; however, no influence of throughfall N deposition on the N in the moss that was sampled within the forest stand was found, nor was any influence of S deposition on the S in the moss found. For the N and S concentrations in the mosses sampled within forest openings, the within-site variability was comparable to the between-site variability, and for the δ(15)N, the within-site variability was lower than the between-site. The results showed that a short distance (<1 m) between the sampling location and the nearest tree canopy increases the N in the moss, and significantly higher values are found in mosses sampled in areas within the forest stand.

Extraction of arsenic compounds from lichens.

Different extraction procedures were applied to improve the extraction efficiency of arsenic compounds from lichens. Two lichen species were chosen from an arsenic-contaminated environment: epiphytic Hypogymnia physodes (L.) Nyl. and terricolous Cladonia rei Schaer. Samples were extracted with water at temperatures of 20, 60 and 90 degrees C, using mixtures of methanol/water (9:1, 1:1 and 1:9), Tris buffer and acetone and the extracts speciated. Water and Tris buffer showed the best extraction efficiency of all extractants used; however, the extraction efficiency was still less than 23%. Since a major fraction of arsenic appeared to be associated with trapped soil particles, a sequential extraction procedure originally designed for soils (extraction steps: (1) 0.05 mol l(-1) (NH(4))(2)SO(4); (2) 0.05 mol l(-1) (NH)(4)H(2)PO(4); (3) 0.2 mol l(-1) NH(4)-oxalate buffer, pH 3.25; (4) mixture of 0.2 mol l(-1) NH(4)-oxalate buffer and 0.1 mol l(-1) ascorbic acid, pH 3.25; (5) 0.5 mol l(-1) KOH) was applied and found to remove 45% of the total arsenic from H. physodes and 83% from C. rei. The lipid-soluble fraction of arsenic was estimated by k(0)-INAA analysis of diethylether extracts and was found to be negligible. An HPLC-UV-HGAFS system was used to determine the arsenic compounds extracted. In both lichen species, arsenous acid, arsenic acid, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, trimethylarsine oxide and glycerol-ribose were detected. In addition, phosphate-ribose was found in H. physodes.