BFR-governmental testing programme

As a consequence of results from recent studies, indicating increasing concentrations of polybrominated diphenyl ethers (PBDEs) in a wide range of environmental samples, governments have begun to consider the need to restrict the production and use of this compound group. Within the EU, it has been decided to cease production and use of the pentamix PBDE formulation, and the industry has already moved to alternative compounds. In Asia, the Japanese industries restrict voluntarily the production and use of polybrominated biphenyls (PBBs), hexabromodiphenyl ether and tetrabromodiphenyl ether. In North America, no such decisions have been taken as yet, and production of the pentamix continues. Ecolabelling and ecological product declarations are also being used in order to accelerate the phase-out process of brominated flame retardant (BFR). They restrict to different degrees the use of BFR in plastic, textiles, flexible floorings and insulating materials. Many governments have also initiated studies intended to provide more information on the octamix and decamix PBDE formulations, and the replacement compounds hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA), regarding their significance as environmental contaminants and to inform the need for further regulatory action. These studies are summarised below.     

Piggery waste treatment by anaerobic digestion and nutrient removal by ionic exchange

Piggery wastes must be treated before their disposal. The high solids content and high chemical oxygen demand of piggery wastes indicated that anaerobic biological treatment could be successfully applied as primary treatment. For that reason, a comparison between upflow anaerobic sludge bed reactor (UASB) and anaerobic fixed bed reactor (AFBR) at a similar organic volumetric loading rate of 5 kg DQO/m³ day was carried out. 60% of the piggery waste COD was removed with the AFBR compared to 40% with the UASB, thus showing a better performance of the AFBR. After 1-h sedimentation secondary process, both anaerobic effluents were treated by ionic exchange with natural zeolite due to their high values of ammoniacal nitrogen (NH⁺₄ plus free NH₃). The high removal of nutrients reported (90%) shows zeolite to be a good choice as tertiary treatment.     

Adjustment formulae for maternal serum alpha-fetoprotein,human chorionic gonadotropin,and unconjugated oestriol to maternal weight and smoking

Serum levels of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and un-conjugated oestriol (uE3) were measured in serum samples of 4131 non-smoking and 1018 smoking women during the second trimester of pregnancy. The levels of all three analytes decreased with increasing body weight. The AFP median was significantly increased in smokers in a dose-response association; hCG decreased by 21 per cent and uE3 decreased by 3 per cent in smokers in a non-dose-related fashion. Regression functions for adjustment of serum levels for weight and smoking should be considered in risk estimation for Down syndrome in order to give a woman's individual risk more precisely.     

Determination of 226Ra at ultratrace level in mineral water samples by sector field inductively coupled plasma mass spectrometry

An analytical procedure has been proposed for the determination of (226)Ra at the low femtogram per ml concentration level in mineral water samples using double focusing sector field ICP-MS (ICP-SFMS). For the pre-concentration and separation of radium from the matrix elements in water a tandem of a laboratory-prepared filter, based on MnO(2), and Eichrom "Sr-specific" resin was used. The recovery of the method was determined to be 70.5%. The limit of detection for (226)Ra determination was 0.02 fg ml(-1), including a pre-concentration factor of 10. In addition, uranium concentration and uranium isotope ratios were measured by ICP-SFMS. In several mineral water samples with a relatively high uranium content, (226)Ra concentrations were found between 0.7-15 fg ml(-1). The effective dose of the contribution was calculated using the radionuclide concentration and dose conversion factors from the World Health Organization, WHO (1993). Assuming a mineral water consumption of 2 l d(-1), a slightly higher calculated dose than the suggested limit for drinking water (0.1 mSv y(-1)) was found in some samples.     

Regulation for environmental protection: The Nanticoke industrial complex,Ontario, Canada

This assessment of the environmental protection regulatory system for the $2.2 billion iron and steel plant, oil refinery, and thermal generating station composing the core of the greenfield Nanticoke industrial complex is based upon: the use of governmental and industrial research in project management; technology and institutional arrangements for environmental protection; evidence of environmental changes to date; analysis of government and industrial approval files; and interviews with government, industry, and interest group representatives. Planning, regulation, and management have been reasonably efficient and effective to the beginning of the operational stage for all three major industries as of spring 1980. Of major future concern, however, is management of the cumulative and synergistic impacts of the industries and associated development on air quality as well as the lands, waters, and sensitive ecosystems of the nearby Lake Erie coast. Continuous monitoring, more comprehensive research, and better overall coordination of government, industrial, and public interests are required if Nanticoke benefits are to be achieved without undue cost to pre-project resource users within and outside the Haldimand-Norfolk region.     

Oxidative degradation of 2,4-xylidine by photosensitization with 2,4,6-triphenylpyrylium: homogeneous and heterogeneous catalysis

The possibility of using zeolites containing the 2,4,6-triphenylpyrylium cation as photocatalysts for the degradation of pollutants has been tested on aqueous xylidine (2,4-dimethylaniline) solutions as models for contaminated wastewaters. The influence of the photocatalyst and substrate concentrations on xylidine oxidation has been investigated in homogeneous solution, by performing a series of experiments chosen according to the experimental design methodology (Doehlert uniform array). The empirical models and the corresponding response surfaces obtained from data analysis have been used for simulating and predicting degradation efficiency. The results have shown that conversion increases with increasing amounts of photocatalyst and decreasing concentration of the model pollutant. The fluorescence of 2,4,6-triphenylpyrylium was quenched by xylidine with a rate constant k(q) of 3.1x10(9)M(-1)s(-1). This result suggests a direct electron transfer between the excited pyrylium salt and xylidine. Because of the limited stability of the photocatalyst in homogeneous media, a pyrylium containing Y-zeolite has been tested for the photocatalytic oxidation of xylidine under heterogeneous conditions. The results suggest that the supported catalyst has a much improved stability and that xylidine oxidation rates remain nearly constant during the whole reaction time. An additional advantage of the pyrylium containing zeolite photocatalyst is that it can be recycled and used for further experiments.     

Fine roots in stands of Fagus sylvatica and Picea abies along a gradient of soil acidification

Root length of naturally grown young beech trees (Fagus sylvatica L.) was investigated in 26 forest plots of differing base saturation and nitrogen deposition. The relative length of finest roots (<0.25 mm) was found to decrease in soils with low base saturation. A similar reduction of finest roots in plots with high nitrogen deposition was masked by the effect of base saturation. The formation of adventitious roots was enhanced in acidic soils. The analysis of 128 soil profiles for fine roots of all species present in stands of either Fagus sylvatica L., Picea abies [Karst.] L. or both showed a decreased rooting depth in soils with < or =20% base saturation and in hydromorphic soils. For base rich, well drained soils an average rooting depth of 108 cm was found. This decreased by 28 cm on acidic, well drained soils. The results suggest an effect of the current soil acidification in Switzerland and possibly also of nitrogen deposition on the fine root systems of forest trees.     

Characterisation of trace elements and methylmercury in an estuarine sediment reference material, IAEA-405

An estuarine sediment sample, IAEA-405, was recently characterised for trace elements and methylmercury (MeHg) for ultimate use as a marine reference material. The reference values were calculated using data sets from 120 laboratories that participated in a world-wide intercomparison exercise. The data evaluation is highlighted, and includes comparisons of different analytical methods, as well as the distribution of data. Overall laboratory performance for this exercise was encouraging: 86 laboratories (72%) reported data with <25% outliers. There was sufficient acceptable data to establish recommended values for 17 elements and information values for a further 15 elements. In addition, a recommended value was established for methylmercury. The estuarine sediment sample, IAEA-405, can be used as a reference material for quality control in the determination of trace elements and methylmercury in moderately polluted sediments.     

Quantification of bacterial lipopolysaccharides (endotoxin) by GC-MS determination of 3-hydroxy fatty acids

A GC-MS method for the quantification of bacterial lipopolysaccharides (LPS, endotoxin) is presented. After hydrolytic cleavage of 3-hydroxy fatty acids (3-OH FAs) from the lipid A region of LPS, derivatisation of both the hydroxyl and the carboxyl group was performed in one step with a mixture of methyl-bis(trifluoracetamide)(MBTFA) and N-methyl-N-(tert-butyldimethylsilyl)trifluoracetamide (MTBSTFA). Using GC-MS in the EI mode with selected ion monitoring (SIM) for analysis, baseline separation of 3-OH FAs (and of possibly interfering 2-OH FAs) was achieved. The sensitivity of the method (LOD 7-50 pg/injection for the different 3-OH FAs investigated) allows for the efficient quantification of LPS in occupational and environmental samples. Degradation of 3-OH FAs as well as of their derivatives during sample preparation and GC-MS separation as a possible source of errors in analytical methods based on 3-OH FA determination is reported for the first time. Thermal elimination of water from the underivatised 3-OH FAs and of trifluoroacetic acid from the derivatives was identified as the cause of degradation. The resulting alpha,beta-unsaturated compounds showing the same mass spectra as the 3-OH FA derivatives were detected as more or less prominent satellite peaks. By using alkaline instead of acidic hydrolysis and cool on-column instead of split/splitless injection, elimination was reduced to an acceptable level.