Determination of brominated flame retardants,with emphasis on polybrominated diphenyl ethers (PBDEs) in environmental and human samples--a review

Analytical methods for the determination of brominated flame retardants (BFRs), with a special emphasis on polybrominated diphenyl ethers (PBDEs) are reviewed. A number of procedures, which can be applied to the analysis of PBDEs and polybrominated biphenyls (PBBs), and in some cases for hexabromocyclododecane (HBCD), in environmental and human samples are described. Because several BFRs, such as tetrabromobisphenol-A (TBBP-A), BDE 209 and, to some extent, HBCD, may require a different approach, specific advice on their analysis is given separately when needed. Sample pretreatment, extraction, cleanup and fractionation, injection techniques, chromatographic separation, detection methods, quality control and method validation are discussed. For each topic, an overview is given of the current status of the field and recommendations for an appropriate analytical approach are presented.     

Gigantism in honeybees: Apis cerana queens reared in mixed-species colonies

The development of animals depends on both genetic and environmental effects to a varying extent. Their relative influences can be evaluated in the social insects by raising the intracolonial diversity to an extreme in nests consisting of workers from more than one species. In this study, we studied the effects of mixed honeybee colonies of Apis mellifera and Apis cerana on the rearing of grafted queen larvae of A. cerana. A. mellifera sealed worker brood was introduced into A. cerana colonies and on emergence, the adults were accepted. Then, A. cerana larvae were grafted for queen rearing into two of these mixed-species colonies. Similarly, A. cerana larvae and A. mellifera larvae were also grafted conspecifically as controls. The success rate of A. cerana queen rearing in the test colonies was 64.5%, surpassing all previous attempts at interspecific queen rearing. After emergence, all virgin queens obtained from the three groups (N=90) were measured morphometrically. The A. cerana queens from the mixed-species colonies differed significantly in size and pigmentation from the A. cerana control queens and closely approximated the A. mellifera queens. It is inferred that these changes in the A. cerana queens reared in the mixed-species colonies can be attributed to feeding by heterospecific nurse bees and/or chemical differences in royal jelly. Our data show a strong impact of environment on the development of queens. The results further suggest that in honeybees the cues for brood recognition can be learned by heterospecific workers after eclosion, thereby providing a novel analogy to slave making in ants.     

Levels and distribution of polybrominated diphenyl ethers in various tissues of birds of prey

In the present study, concentrations and tissue distribution of polybrominated diphenyl ethers (PBDEs; IUPAC # 28, 47, 99, 100, 153, 154, 183, and 209) were examined in brain, adipose tissue, liver, muscle, and serum of birds of prey. Median SigmaPBDE levels (BDE 28-183) in the tissues of sparrowhawks ranged from 360 to 1900 ng/g lipid weight (lw), which was in general one order of magnitude higher than in the tissues of common buzzards (26-130 ng/g lw). There were no differences in PBDE congener patterns between the various tissues within individuals of a certain species. Inter-species differences in PBDE patterns and in particular the percentage of BDE 99, 100 and 153 were, however, pronounced between sparrowhawk and common buzzard. BDE 209 was detected in nearly all serum and in some liver samples, but not in any other tissues. This observation suggests that exposure to BDE 209 is low or that this congener is poorly accumulated. Passive (lipid content related) diffusion could not completely describe the PBDE tissue distribution, e.g. the lowest PBDE-load was measured in brain, a fairly lipid rich tissue.     

Determination of naturally occurring MTBE biodegradation by analysing metabolites and biodegradation by-products

Methyl tert-butyl ether (MTBE) is one of the main additives in gasoline. Its degradation is known to be difficult in natural environments. In this study, significant MTBE degradation is demonstrated at a contaminated site in Leuna (eastern Germany). Since the extent of the plume appeared to be constant over the last 5 years, an extended study was performed to elucidate the degradation processes. Special attention was paid to the production, accumulation and degradation of metabolites and by-products. Groundwater samples from 105 monitoring wells were used to measure 20 different substances. During the degradation process, several intermediates such as tert-butyl alcohol (TBA), tert-butyl formate, formate and lactate were produced. However, the potentially carcinogenic by-product methacrylate was not detected in several hundred samples. At the Leuna site, MTBE degradation occurred under microaerobic conditions. In contrast to hydrocarbons and BTEX, there was no evidence for anaerobic MTBE degradation. Among the degradation products, TBA was found to be a useful intermediate to identify MTBE degradation, at least under microaerobic conditions. TBA accumulation was strongly correlated to MTBE degradation according to the kinetic properties of both degradation processes. Since maximum degradation rates (v(max)) and k(m) values were higher for MTBE (v(max)=2.3 mg/l/d and k(m)=3.2 mg/l) than for TBA (v(max)=1.35 mg/l/d and k(m)=0.05 mg/l), TBA significantly accumulated as an intermediate by-product. The field results were supported by bench scale model aquifer experiments.     

Phytoremediation organischer Schadstoffe

Ohne Zusammenfassung     

Das Biologische System der Elemente

Ohne Zusammenfassung DOI:http://dx.doi.org/10.1065/uwsf2000.02.001     

Precipitation scavenging coefficient: influence of measured aerosol and raindrop size distributions

Precipitation scavenging coefficients, widely used in pollution studies, are derived from microphysical parameterisations of aerosol particles and raindrop populations and parameterisations of their interactions. The present study investigates the effects of measured aerosol and raindrop size distributions in a microphysical polydisperse framework. The interactions between aerosol and raindrops parameterised as collision efficiency are explicitly included to account for Brownian diffusion, inertial impaction and interception. Estimated values of the polydisperse scavenging coefficients exhibit variations of orders of magnitude depending on the aerosol type and almost no variation with the raindrop size distributions. For practical use, linear relationships between the scavenging coefficients and rain intensity for different aerosol types are derived.     

Urine concentrations of selected trace metals in a cohort of Irish adults

Environmental Science and Pollution Research - Human biomonitoring studies are of increasing importance in regulatory toxicology; however, there is a paucity of human biomonitoring data for the...     

Cobalt extraction from spent lithium-ion battery cathode material using a sulfuric acid solution containing SO2

Journal of Material Cycles and Waste Management - To increase the degree of cobalt (Co) extraction, the process of the cathode material leaching was performed in a sulfuric acid (H2SO4) solution...