Understanding the fate and transport of petroleum hydrocarbons from coal tar within gasholders

Coal tars have been identified as posing a threat to human health due to their toxic, mutagenic and carcinogenic characteristics. Workers involved in former gasholders decommissioning are potentially exposed to relevant concentrations of volatile and semi-volatile hydrocarbons upon opening up derelict tanks and during tar excavation/removal. While information on contaminated sites air-quality and its implications on medium-long term exposure is available, acute exposure issues associated with the execution of critical tasks are less understood. Calculations indicated that the concentration of a given contaminant in the gasholder vapour phase only depends on the coal tar composition, being only barely affected by the presence of water in the gasholder and the tar volume/void space ratio. Fugacity modelling suggested that risk-critical compounds such as benzene, naphthalene and other monocyclic and polycyclic aromatic hydrocarbons may gather in the gasholder air phase at significant concentrations. Gasholder emissions were measured on-site and compared with the workplace exposure limits (WELs) currently in use in UK. While levels for most of the toxic compounds were far lower than WELs, benzene air-concentrations where found to be above the accepted threshold. In addition due to the long exposure periods involved in gasholder decommissioning and the significant contribution given by naphthalene to the total coal tar vapour concentration, the adoption of a WEL for naphthalene may need to be considered to support operators in preventing human health risk at the workplace. The Level I fugacity approach used in this study demonstrated its suitability for applications to sealed environments such as gasholders and its further refining could provide a useful tool for land remediation risk assessors.     

Improved performance of a biomaterial-based cation exchanger for the adsorption of uranium(VI) from water and nuclear industry wastewater

The amine-modified polyhydroxyethylmethacrylate (poly(HEMA))-grafted biomaterial (tamarind fruit shell, TFS) carrying carboxyl functional groups at the chain end (PGTFS-COOH) was prepared and used as an adsorbent for the removal of uranium(VI) from water and nuclear industry wastewater. FTIR spectral analysis revealed that U(VI) ions and PGTFS-COOH formed a chelate complex. The adsorption process was relatively fast, requiring only 120 min to attain equilibrium. The adsorption kinetic data were best described by the pseudo-second-order equation. The equilibrium adsorption data were correlated with the Sips isotherm model. The maximum U(VI) ions uptake with PGTFS-COOH was estimated to be 100.79 mg/g. The complete removal of 10 mg/L U(VI) from simulated nuclear industry wastewater was achieved by 3.5 g/L PGTFS-COOH. The reusability of the adsorbent was demonstrated over 4 cycles using NaCl (1.0 M) + HCl (0.5 M) solution mixture to de-extract the U(VI). The results show that the PGTFS-COOH tested is very promising for the recovery of U(VI) from water and wastewater.     

Mass balance approach to estimating radionuclide loads and concentrations in edible fish tissues using stable analogues

Humans can consume a number of types of biota tissues, which have varying propensities to accumulate radionuclides. As a result, depending upon the biota species, the radionuclide and the tissue under consideration, it may be necessary to estimate the percent radionuclide load in specific edible tissues, and in cases where whole organisms are consumed, to estimate the radionuclide load in the whole body of an organism, based on data that have been collected for individual tissues. To accomplish this, data were compiled that can be used to estimate the partitioning patterns and percent loads of various groups of elements in edible tissues of freshwater fishes. General trends in partitioning, such as those provided in this paper, can be used to predict radionuclide transfer to humans and the corresponding potential radiological dose to humans via dietary pathways, in this case following the consumption of fish.     

A review and test of predictive models for the bioaccumulation of radiostrontium in fish

Empirical relations between the ⁹⁰Sr concentration factor (CF) and the calcium concentration in freshwater aquatic systems have previously been determined in studies based on data obtained prior to the Chernobyl accident. The purpose of the present research is to review and compare these models, and to test them against a database of post-Chernobyl measurements from rivers and lakes in Ukraine, Russia, Belarus and Finland. It was found that two independently developed models, based on pre-Chernobyl empirical data, are in close agreement with each other, and with empirical data. Testing of both models against new data obtained after the Chernobyl accident confirms the models’ predictive ability. An investigation of the influence of fish size on ⁹⁰Sr accumulation showed no significant relationship, though the data set was somewhat limited.     

Common buzzards (Buteo buteo) bio-indicators of heavy metals pollution in Sicily (Italy)

The aim of this study was to evaluate the accumulation of toxic (As, Cd and Pb) and essential (Cu, Mn and Zn) metals in samples (feathers, liver, kidney, lung, intestine and muscle) of common buzzards (Buteo buteo) from Sicily, used as bio-indicators for monitoring environmental metals pollution. All samples of buzzards were collected at the “Recovery Center of Wild Fauna” of Palermo, through the Zooprophilactic Institute. The quantitative determinations of metals were carried out using an atomic absorbtion spectrophotometer (AAS). The results obtained showed the presence of metals in all samples analyzed. For toxic metals the highest levels of Pb and As were found in liver and those of Cd in kidney; for essential metals Zn levels were higher than Cu and Mn in all tissues analyzed. Significant differences are observed in metal levels between female and male and juvenile and adult bird samples.Highest metal levels found in liver, kidney and muscle can be considered indicative of chronic exposure to metals while the presence of metals in feathers can be consequential to storing and elimination processes. The results obtained suggest that common buzzards (Buteo buteo) may be very useful as bio-indicators for monitoring environmental pollution.     

Effect of americium-241 on luminous bacteria. Role of peroxides

The effect of americium-241 (²⁴¹Am), an alpha-emitting radionuclide of high specific activity, on luminous bacteria Photobacterium phosphoreum was studied. Traces of ²⁴¹Am in nutrient media (0.16-6.67 kBq/L) suppressed the growth of bacteria, but enhanced luminescence intensity and quantum yield at room temperature. Lower temperature (4 °C) increased the time of bacterial luminescence and revealed a stage of bioluminescence inhibition after 150 h of bioluminescence registration start. The role of conditions of exposure the bacterial cells to the ²⁴¹Am is discussed. The effect of ²⁴¹Am on luminous bacteria was attributed to peroxide compounds generated in water solutions as secondary products of radioactive decay. Increase of peroxide concentration in ²⁴¹Am solutions was demonstrated; and the similarity of ²⁴¹Am and hydrogen peroxide effects on bacterial luminescence was revealed. The study provides a scientific basis for elaboration of bioluminescence-based assay to monitor radiotoxicity of alpha-emitting radionuclides in aquatic solutions.     

High concentrations of polybrominated diphenylethers (PBDEs) in breast adipose tissue of California women

We measured major PBDEs and PCBs in breast adipose tissues of California women participating in a breast cancer study in the late 1990s. Samples were analyzed using gas chromatography with electron impact ionization and tandem mass spectrometry detection. The congener profile observed was: BDE47>BDE99>BDE153>BDE100>BDE154 and PCB153>PCB180>PCB138>PCB118. Whereas high correlations were observed within each chemical class, very weak correlations appeared between classes, pointing to different exposure pathways. Weak negative associations were observed for PBDE congeners and age. Our PBDE data are among the highest reported, exceeding data from the National Health and Nutrition Examination Survey and consistent with the high use of PBDEs in California. These data may be helpful in establishing a baseline for PBDE body burdens to gauge changes over time as a result of restrictions in the use of PBDE formulations.     

Estrogenic and androgenic activities in total plasma measured with reporter-gene bioassays: relevant exposure measures for endocrine disruptors in epidemiologic studies?

Measurements of estrogenic and androgenic activities in total plasma with Chemically Activated LUciferase gene eXpression (CALUX?) bioassays could provide biologically relevant measures for exposure to endocrine disruptors in epidemiologic studies. The objective of this study was to explore the effects of a variety of sources of potential endocrine disruptors on estrogenic and androgenic activities in total plasma measured by CALUX?. Plasma samples and interview data on sources of potential endocrine disruptors were collected from 108 men with different exposures profiles. CALUX? measurements (BioDetection Services) involved human U2-OS cell lines controlled by the estrogen receptor alpha and the androgen receptor. Mean differences (beta) in 17β-estradiol equivalents (EEQs) and dihydrotestosterone equivalents (AEQs) between exposure groups were estimated using general linear models. Mean plasma AEQs and EEQs were 9.1×10(-1)ng/ml and 12.0pg/ml, respectively. Elevated AEQs were found in smokers (beta 1.9 (95%CI 0.1-3.6)×10(-1)ng/ml) and heavy drinkers (1.4 (0.2-3.1)×10(-1)ng/ml), and in men occupationally exposed to disinfectants (1.6 (0.3-3.5)×10(-1)ng/ml) or welding/soldering fumes (1.4 (-0.2-2.9)×10(-1)ng/ml). Occupational exposure to pesticides, disinfectants, and exhaust fumes seemed to be associated with increased plasma EEQs: 1.5 (-0.2-3.2)pg/ml, 2.1 (0.2-3.9)pg/ml, and 2.9 (0.6-5.2)pg/ml, respectively. Moderate to high plasma dioxin levels, measured in a subgroup by the dioxin-responsive CALUX?, were accompanied by a 20% increase in AEQs. This is the first study in which CALUX? was used to assess hormone activities in total plasma. Although the results are not yet readily interpretable, they indicate that these measurements can be valuable for epidemiologic studies on endocrine disruptors and give direction for further research.     

Effect of water pH and total dissolved solids on the species diversity of pelagic zooplankton in lakes: A statistical analysis

Statistical analysis of the combined influence of lake surface area (S), water pH, and total dissolved solids (TDS) on the formation of zooplankton communities in lakes has been made on the basis of available data on the number of species (N _sp ) of pelagic zooplankton in 256 lakes of the temperate zone of Europe, Asia, and North America. Graphic analysis and analysis of variance have shown that extremely high or extremely low values of pH and TDS inhibit lake zooplankton. If the value of one of these factors is extremely high, any increase in the other factor is favorable for the inhibited zooplankton, and this second factor determines the value of N _sp .     

Variation in certain characters and properties of scotch pine needles in geographic cultures

Morphophysiological and anatomical characters of needles that are used for characterizing infraspecific taxa have been studied in Scotch pine geographic cultures established in the forest-steppe zone of Siberia. Variation in these characters has been revealed, which reflects the polymorphic structure of the species and the effect of natural selection on the composition of populations in new natural-cimatic conditions.