Size-segregated trace elements in continental suburban aerosols: seasonal variation and estimation of local,regional, and remote emission sources

We have measured trace element contents in suburban aerosols from six size fractions in the range of PM_0.27–16 from a background station in Belgrade (Serbia). The distribution and concentration of elements were determined within each of the investigated Dp fractions with emphasis on the fine and coarse modes. Fine/coarse mode ratios of element can provide information regarding their anthropogenic or natural origin. Analysis of seasonal variations of element contents in fine and coarse mode show that Cd, Co, K, and V have higher concentrations in the fine mode during heating season, while Fe contents are lower. In the coarse mode, Cu and V have higher concentrations during the heating season, while Al, Fe, Mg, Mn, and Sb contents are lower. We also apply a distribution probability model (normal, log-normal, and three-parameter Weibull) as new approach to estimate the distances of emission sources that can contribute to pollutant contents in particulate matter of the investigated location.     

Characterization and source identification of polycyclic aromatic hydrocarbons (PAHs) in river bank soils

Elevated PAH concentrations were detected in bank soils along the Mosel and Saar Rivers in Germany. Information on the identification of PAH sources in this area however remains unclear. This study was able to characterize the PAH sources by application of several approaches, including consideration of the distribution patterns of 45 PAHs (including 16 EPA PAHs and some alkyl PAHs), specific PAH ratios, distribution patterns of n-alkanes and principal component analysis (PCA). In addition, the efficiency of the tested approaches was assessed. The results from the application of the various source identification methods showed that pyrogenic PAHs dominate soil samples collected upstream of the confluence of the Mosel and Saar Rivers, and petrogenic and pyrogenic PAHs dominate samples downstream of the confluence. Based on the analysis of reference materials and organic petrography, the petrogenic input was found to be dominated by coal particles. More detailed information on the petrogenic sources was provided by the n-alkane analyses. The current study concludes that to accurately determine the origin of PAHs, several identification methods must be applied.     

A rapid lateral flow immunoassay for the detection of fungal alpha-amylase at the workplace

Fungal alpha-amylase is a flour supplement which is added to improve the quality of bakery products. Various studies have shown that exposure to this enzyme is an important risk factor for the development of bakers' allergy and this allergy is reported to be one of the most frequent causes of occupational asthma. A rapid assay was developed to monitor exposure to occupational allergens directly at the workplace. The sensitivity of the developed assay is 0.32 ng amylase mL(-1) in a buffer system with the commercially available alpha-amylase preparation Fungamyl 1600S as the standard. Initial validation tests (n = 33) were performed with airborne and settled dust from an industrial bakery. The new lateral flow immunoassay detected amylase in 22 of the 26 samples regarded as positive in an enzyme immunoassay, and was negative for all seven enzyme immunoassay-negative samples, while the four lateral flow immunoassay-negative/enzyme immunoassay-positive samples all had levels below 2 ng mL(-1). The sensitivity of 2 ng mL(-1) of the amylase lateral flow immunoassay is sufficient for first screening purposes and, therefore, this simple and rapid assay may allow direct on-site demonstration of work-related hazards of bio-allergen exposure. This would be particularly useful in occupational hygiene practice, especially in traditional or small-scale bakeries which lack the technological skills for testing the exposure to respiratory allergens.     

Biodegradation of Thermoplastic Polyurethanes from Vegetable Oils

Thermoplastic urethanes based on polyricinoleic acid soft segments and MDI/BD hard segments with varied soft segment concentration were prepared. Soft segment concentration was varied from, 40 to 70 wt%. Biodegradation was studied by respirometry. Segmented polyurethanes with soft segments based on polyricinoleic acid degrade relatively slow losing about 11% carbon after 30 days, but faster than corresponding petrochemical polyesterurethanes. Since biodegradation proceeds mainly through the soft segments, higher soft segment content polymers displayed slightly higher biodegradation. Polyurethanes with dispersed hard domains in the soft phase displayed slightly faster biodegradation than those with co-continuous morphology. Polyester diol degrades slower than castor oil but significantly faster than the polyurethanes with built in soft segments from the same diol. Castor oil biodegrades slower than soybean oil.     

Detection of elements and radioactivity in pellets from long-eared owls (Asio otus) inhabiting the city of Belgrade (Serbia)

In this study, we analysed pellets from long-eared owls (Asio otus) collected from four localities in Belgrade (Serbia). The pellets contained the remains of prey, namely voles (Arvicola terrestris) and field mice (Apodemus agrarius). The concentrations of 14 elements (Ca, P, Mg, Na, K, Fe, Zn, Sr, Ba, Mn, Ti, Cu, Si, B) were evaluated in whole pellets and in samples containing only bone tissue, which were dissected from the whole pellet. The increased levels of certain elements, including Mn, Zn, Ba, Cu and radioactive ⁴⁰K, indicate contamination of the soil by various sources, such as industrial plants and agricultural practices. From the results presented in this article, we suggest that the analysis of owl pellets may indicate the quality of the local environment.     

REP-LECOTOX: an example of FP 6 INCO project to strengthen ecotoxicological research in WBC (Western Balkan countries)

Background

In order to map exceedances of critical atmospheric deposition loads for nitrogen (N) surface data on the atmospheric deposition of N compounds to terrestrial ecosystems are needed. Across Europe such information is provided by the international European Monitoring and Evaluation Programme (EMEP) in a resolution of 50 km by 50 km, relying on both emission data and measurement data on atmospheric depositions. The objective of the article at hand is on the improvement of the spatial resolution of the EMEP maps by combining them with data on the N concentration in mosses provided by the International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops (ICP Vegetation) of the United Nations Economic Commission for Europe (UNECE) Long-range Transboundary Air Pollution (LTRAP) Convention.

Methods

The map on atmospheric depositions of total N as modelled by EMEP was intersected with geostatistical surface estimations on the N concentration in mosses at a resolution of 5 km by 5 km. The medians of the N estimations in mosses were then calculated for each 50 km by 50 km grid cell. Both medians of moss estimations and corresponding modelled deposition values were ln-transformed and their relationship investigated and modelled by linear regression analysis. The regression equations were applied on the moss kriging estimates of the N concentration in mosses. The respective residuals were projected onto the centres of the EMEP grid cells and were mapped using variogram analysis and kriging procedures. Finally, the residual and the regression map were summed up to the map of total N deposition in terrestrial ecosystems throughout Europe.

Results and discussion

The regression analysis of the estimated N concentrations in mosses and the modelled EMEP depositions resulted in clear linear regression patterns with coefficients of determination of r ² = 0.62 and Pearson correlations of r _p = 0.79 and Spearman correlations of r _s = 0.70, respectively. Regarding the German territory a nationwide mean of 18.1 kg/ha/a (standard deviation: 3.49 kg/ha/a) could be derived from the resulting map on total N deposition in a resolution of 5 km by 5 km. Recent updates of the modelled atmospheric deposition of N provided a similar estimate for Germany.

Conclusions

The linking of modelled EMEP data on the atmospheric depositions of total N and the accumulation of N in mosses allows to map the deposition of total N in a high resolution of 5 km by 5 km using empirical moss data. The mapping relies on the strong statistical relationship between both processes that are physically and chemically related to each other. The mapping approach thereby relies on available data that are both based on European wide harmonized methodologies. From an ecotoxicological point of view the linking of data on N depositions and those on N bioaccumulation can be considered a substantial progress.     

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.     

Rapid one-step assays for on-site monitoring of mouse and rat urinary allergens

Allergy to rodent proteins is common among laboratory animal workers. Sensitive methods to measure exposure to these allergens have been developed. These assays are, however, expensive, time-consuming, and require a laboratory facility and methodological expertise. A simple method to screen for allergen spread, or to test whether hygiene standards are maintained, would be useful. Lateral flow immunoassays (LFIAs) are especially suited for field settings; the tests are simple and results are visible within minutes. LFIAs were developed for detection of the rodent urinary allergens Mus m 1 and Rat n 1. Pilot studies were performed in animal facilities in three countries using both extracts from airborne dust samples and samples collected by wiping surfaces. For comparison and determination of sensitivity, the concentrations of rodent urinary allergens in the samples were also measured using enzyme immunoassays (EIAs). The LFIAs for rat and mouse urinary allergens had a detection limit of 31 pg allergen per mL in a buffer system with purified allergen standards. Results of environmental dust extracts tested in LFIAs correlated well with levels obtained using EIAs. Spread of rodent allergens, or non-adherence to hygiene around laboratory animal facilities, may aggravate rodent allergy. Using a simple, sensitive one-step assay, allergens can be detected to prevent allergen exposure. The results reveal that the rapid assays are suited for on-site demonstration of exposure to rodent allergens, and thus, useful in occupational hygiene practice.