Phyto/rhizoremediation studies using long-term PCB-contaminated soil

Purpose  

Polychlorinated biphenyls (PCBs) represent a large group of recalcitrant environmental pollutants, differing in the number of chlorine atoms bound to biphenyl ring. Due to their excellent technological properties, PCBs were used as heat-transfer media, for filling transformers and condensers, as paint additives, etc. With increasing knowledge of their toxicity, transfer to food chains and accumulation in living organisms, their production ended in most countries in the 1970s and in 1984 in the former Czechoslovakia. But even a quarter of century after the PCB production ceased, from contaminated areas, the volatile PCBs evaporate and contaminate much larger areas even at very distant parts of the world. For this reason, PCBs still represent a global problem. The main method of PCB removal from contaminated environment is at present the expensive incineration at high temperatures. With the aim of finding effective alternative approaches, we are studying biological methods for PCB removal from the environment. In this paper, we summarise 10 years of studies using long-term PCB-contaminated soil from a dumpsite in South Bohemia, targeted for the use of plants (phytoremediation) and their cooperation with microorganisms in the root zone (rhizoremediation).     

Twelve years of assessing the quality of preimplantation genetic testing for monogenic disorders

Objective

Genomics Quality Assessment has provided external quality assessments (EQAs) for preimplantation genetic testing (PGT) for 12 years for eight monogenic diseases to identify sub-optimal PGT strategies, testing and reporting of results, which can be shared with the genomics community to aid optimised standards of PGT services for couples.

Method

The EQAs were provided in two stages to mimic end-to-end protocols. Stage 1 involved DNA feasibility testing of a couple undergoing PGT and affected proband. Participants were required to report genotyping results and outline their embryo testing strategy. Lymphoblasts were distributed for mock embryo testing for stage 2. Submitted clinical reports and haplotyping results were assessed against peer-ratified criteria. Performance was monitored to identify poor performance.

Results

The most common testing methodology was short tandem repeat linkage analysis (59%); however, the adoption of single nucleotide polymorphism-based platforms was observed and a move from blastomere to trophectoderm testing. There was a variation in testing strategies, assigning marker informativity and understanding test limitations, some clinically unsafe. Critical errors were reported for genotyping and interpretation.

Conclusion

EQA provides an overview of the standard of preimplantation genetic testing-M clinical testing and identifies areas of improvement for accurate detection of high-risk embryos.     

Application of impregnated filters to determination of smoke and ammonia

Whatman No. 1 filters impregnated with a 3% solution of oxalic acid in ethanol which are used for elimination of ammonia from the air stream before entering the absorber for collecting SO₂, were tested for a possible application (a) in the spectrophotometric determination of ammonia with Nessler's reagent and (b) in the reflectometric determination of smoke. It was shown that impregnated filters were as suitable for the determination of ammonia as absorbing solution and as applicable for smoke measurement as untreated filters. Further, the advantage of using impregnated filters for sampling ammonia lies in avoiding the interference of organic vapours which may occur, if absorbing solution is used.     

Improved recycling with life cycle information tagged to the product

Rising demand for product means that the recycling of materials is now more important than ever, saving a lot of energy embedded in materials, thus reducing CO₂ emissions. Providing relevant information can raise the recycling efficiency, which is too low at present.A Recycling Information Matrix (RIM) concentrating on Waste Electrical and Electronic Equipment (WEEE) is suggested in order to facilitate and improve materials recycling. Each RIM focuses on a recycling target, and for each type of product a WEEE vector is constructed. The WEEE vector contains nine hexadecimal numbers where core-recycling info is stored.The WEEE vector can provide direct recycling information escorting the product. Another possibility is to individually identify every single product via RFID technology, giving the potential to look for relevant recycling information in databases. This offers the opportunity to add waste-handling information after the product has entered the market. This would be useful, for example, in tracking substances regarded as non-toxic at time of production which might later be proven to be the opposite.This paper is based on study visits at recycling facilities in Sweden and on many student EcoDesign projects including disassembly of consumer products. Research is done on a focused disassembly of dishwashers and on a polymer recycling experiment at a recycling plant for freezers and refrigerators. Possible escort memories are also studied, especially Radio Frequency Identification Devices (RFID).