Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in e-waste plastic in Nigeria.

Plastics from cathode ray tube (CRT) casings were sampled in Nigeria and analysed for their polybrominated dibenzo-p-dioxin and dibenzofuran (PBDD/F) content. PBDD/Fs, consisting mainly of PBDFs, were detected in BFR containing plastic with a median (mean) concentration of 18,000 ng/g (41,000 ng/g). The PBDD/Fs levels were highest in samples containing PBDEs, but the levels of PBDFs were two orders of magnitude higher than the levels reported in the technical PBDE mixtures and where frequently exceeding 1000 µg/g of PBDE content. These higher levels are likely to arise from additional transformation of PBDEs during production, use, recycling, or storage, but the processes responsible were not identified in this study. PBDD/Fs in CRT casings containing1,2-bistribromophenoxyethane (TBPE) were dominated by tetrabrominated dibenzo-p-dioxin (TBDDs) with concentrations around 10 µg/g of the TBPE content. The PBDD/Fs in CRT casings containing tetrabromobisphenol A (TBBPA) were found at concentrations around 0.1 µg/g of TBBPA levels. Casings treated with TBPE or TBBPA often contained PBDEs (and PBDF) as impurities-probably originating from recycled e-waste plastics. It was estimated that the 237,000 t of CRT casings stockpiled in Nigeria contain between 2 and 8 t of PBDD/Fs. The total PBDD/F contamination in polymers arising from total historic PBDE production/use is estimated in the order of 1000 t. TEQ values of CRT samples frequently exceeded the Basel Convention's provisional low POPs content of 15 ng TEQ/g. Due to the significant risks to health associated with PBDD/Fs, more detailed studies on the exposure routes from PBDD/Fs in stockpiles are needed.

Behavior and fate of anthropogenic substances at a Swedish sewage treatment plant.

The behavior and fate of anthropogenic substances during sewage treatment were investigated at a sewage treatment plant (STP) in Sweden which uses mechanical, chemical, and biological methods for sewage treatment and anaerobic digestion of sludge. Influent and effluent water, and sludge from two specific treatment sites were sampled. Mass balances were calculated from measured concentrations of various substances and estimates of the mass flows (water, solids) throughout the process. The results show that the metals (As, Cd, Cr, Hg, Pb) and the majority of PCBs, PCDD/Fs, and PBDEs enter and leave the STP bound to particles. Triclosan and di-(2-ethylhexyl)phthalate adsorb to sludge to a high degree, while the metals (Co, Cu, Ni, Zn) and organophosphate esters seem to pass through the STP unaffected by the process. Generally, the STP was better in removing lipophilic than water soluble compounds. Most of the substances end up in anaerobically digested sludge in almost the same concentrations as in primary sludge. A fugacity based STP model was evaluated for its ability to predict the behavior and fate of the substances and was found feasible for lipophilic compounds. It did however produce poor predictions for water soluble compounds such as organophosphate esters (overestimated) and antibacterial agents (underestimated).

Phenotypic biomonitoring using multivariate flow cytometric analysis of multi-stained microorganisms.

A new method for monitoring phenotypic profiles of pure cultures and complex microbial communities was evaluated. The approach was to stain microorganisms with a battery of fluorescent dyes prior to flow cytometry analysis (FCM) and to analyse the data using multivariate methods, including principal component analysis and partial least squares. The FCM method was quantitatively evaluated using different mixtures of pure cultures as well as microbial communities. The results showed that the method could quantitatively and reproducibly resolve both populations and communities of microorganisms with 5% abundance in a diverse microbial background. The feasibility of monitoring complex microbial communities over time during the biodegradation of naphthalene using the FCM method was demonstrated. The biodegradation of naphthalene occurred to differing extents in microcosms representing three different types of aromatic-contaminated groundwater and a sample of bio-basin water. The FCM method distinguished each of these four microbial communities. The phenotypic profiles were compared with genotypic profiles generated by random-amplified polymorphic DNA analysis. The genotypic profiles of the microbial communities described only the microbial composition, and not their functional change, whereas the phenotypic profiles seemed to contain information on both the composition and the functional change of the microorganisms. Furthermore, event analysis of the FCM data showed that microbial communities with initially differing compositions could converge towards a similar composition if they had a capacity for high levels of degradation, whereas microbial communities with similar initial compositions could diverge if they differed in biodegrading ability.

Pressurised liquid extraction of polycyclic aromatic hydrocarbons from contaminated soils.

The reliability and efficiency of the pressurised liquid extraction technique (PLE) for extracting polycyclic aromatic hydrocarbons (PAHs) from contaminated soil has been investigated. Experimental design was used to study the influence of seven extraction variables (sample load, solvents used, solvent ratios, pressure, temperature, extraction time, and rinse volume). The results show that large sample loads in combination with small solvent volumes may result in low extraction efficiency. They also indicate that the recovery of low-molecular-mass PAHs is reduced by low extraction temperatures. The exact settings of the other variables are, however, less significant for the extraction efficiency. Repeated extractions at optimised settings of the tested variables show that PLE is an exhaustive extraction technique that generally results in high yields. In addition, extraction of a certified reference material (CRM 103-100) revealed that the method is both accurate and precise. Another finding was that adding the internal standard on top of the soil in the extraction cell causes considerable over-estimation of the concentrations when large samples are extracted with small solvent volumes. This is because the PLE-cell resembles a chromatographic column, so compounds added to the top of the soil layer have a longer distance to travel through the soil compared to the average distance of the native compounds, which are distributed evenly throughout the column. We therefore recommend that the internal standard should be added to the extract immediately after the extraction or, alternatively, carefully mixed with the sample prior to extraction.

Finasteride following balloon dilatation of the prostate. A double-blind, placebo-controlled, multicenter study.

BACKGROUND AND AIMS: To evaluate the efficacy, safety and tolerability of finasteride administered for 24 months following successful balloon dilatation in patients with benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: 75 patients with moderate to severe symptoms of benign prostatic hyperplasia were first treated with balloon dilatation. After a 4-week placebo runin period, 64 patients with successful dilatation and over 50 % reduction in symptoms were randomized to receive either finasteride (33 pts.) at 5 mg/day or placebo (31 pts.) for 24 months. Altogether 12 patients dropped out at some stage, and the final analysis hence included 27 patients in the finasteride group and 25 patients in the placebo group. RESULTS: The symptom scores increased by an average of 3.2 points in the finasteride group and 4.4 points in the placebo group during two years. The mean maximum flow in the finasteride group remained constant: 13.7 ml/s at baseline and 13.9 ml/s at 24 months. In the placebo group the mean maximum flow decreased from 13.3 ml/sec to 11.2 ml/s. During the two-year study period, neither of the groups displayed any changes in residual urine. The above mentioned changes were not statistically significant, however. Prostate volume and serum PSA were significantly lower in the finasteride group (p < 0.001). The groups did not differ with regard to side-effects. CONCLUSIONS: On the basis of the findings, BPH patients with moderate to severe symptoms can be treated with balloon dilatation. The effect of balloon dilatation is quick, and it alleviates the patients' symptoms immediately. Finasteride treatment maintains the positive effect of balloon dilatation. This combination of treatment is tolerated well and side-effects are rare. The favourable effect of balloon dilatation was maintained for at least two years. Finasteride treatment diminished significantly both prostate volume and serum prostate-specific antigen after balloon dilatation compared to placebo treatment.