Legal situation and current practice of waste incineration bottom ash utilisation in Europe

Almost 500 municipal solid waste incineration plants in the EU, Norway, and Switzerland generate about 17.6 Mt/a of incinerator bottom ash (IBA). IBA contains minerals and metals. Metals are mostly separated and sold to the scrap market and minerals are either disposed of in landfills or utilised in the construction sector. Since there is no uniform regulation for IBA utilisation at EU level, countries developed own rules with varying requirements for utilisation. As a result from a cooperation network between European experts an up-to-date overview of documents regulating IBA utilisation is presented. Furthermore, this work highlights the different requirements that have to be considered. Overall, 51 different parameters for the total content and 36 different parameters for the emission by leaching are defined. An analysis of the defined parameter reveals that leaching parameters are significantly more to be considered compared to total content parameters. In order to assess the leaching behaviour nine different leaching tests, including batch tests, up-flow percolation tests and one diffusion test (monolithic materials) are in place. A further discussion of leaching parameters showed that certain countries took over limit values initially defined for landfills for inert waste and adopted them for IBA utilisation. The overall utilisation rate of IBA in construction works is approximately 54 wt.%. It is revealed that the rate of utilisation does not necessarily depend on how well regulated IBA utilisation is, but rather seems to be a result of political commitment for IBA recycling and economically interesting circumstances

Bestrophin1: A Gene that Causes Many Diseases

Bestrophinopathies are a group of clinically distinct inherited retinal dystrophies that lead to the gradual loss of vision in and around the macular area. There are no treatments for patients suffering from bestrophinopathies, and no measures can be taken to prevent visual deterioration in those who have inherited disease-causing mutations. Bestrophinopathies are caused by mutations in the Bestrophin1 gene (BEST1), a protein found exclusively in the retinal pigment epithelial (RPE) cells of the eye. Mutations in BEST1 affect the function of the RPE leading to the death of overlying retinal cells and subsequent vision loss. The pathogenic mechanisms arising from BEST1 mutations are still not fully understood, and it is not clear how mutations in BEST1 lead to diseases with distinct clinical features. This chapter discusses BEST1, the use of model systems to investigate the effects of mutations and the potential to investigate individual bestrophinopathies using induced pluripotent stem cells

Efflux Protein Expression in Human Stem Cell-Derived Retinal Pigment Epithelial Cells

Retinal pigment epithelial (RPE) cells in the back of the eye nourish photoreceptor cells and form a selective barrier that influences drug transport from the blood to the photoreceptor cells. At the molecular level, ATP-dependent efflux transporters have a major role in drug delivery in human RPE. In this study, we assessed the relative expression of several ATP-dependent efflux transporter genes (MRP1, -2, -3, -4, -5, -6, p-gp, and BCRP), the protein expression and localization of MRP1, MRP4, and MRP5, and the functionality of MRP1 efflux pumps at different maturation stages of undifferentiated human embryonic stem cells (hESC) and RPE derived from the hESC (hESC-RPE). Our findings revealed that the gene expression of ATP-dependent efflux transporters MRP1, -3, -4, -5, and p-gp fluctuated during hESC-RPE maturation from undifferentiated hESC to fusiform, epithelioid, and finally to cobblestone hESC-RPE. Epithelioid hESC-RPE had the highest expression of MRP1, -3, -4, and P-gp, whereas the most mature cobblestone hESC-RPE had the highest expression of MRP5 and MRP6. These findings indicate that a similar efflux protein profile is shared between hESC-RPE and the human RPE cell line, ARPE-19, and suggest that hESC-RPE cells are suitable in vitro RPE models for drug transport studies. Embryonic stem cell model might provide a novel tool to study retinal cell differentiation, mechanisms of RPE -derived diseases, drug testing and targeted drug therapy

Promises of stem cell therapy for retinal degenerative diseases

With the development of stem cell technology, stem cell-based therapy for retinal degeneration has been proposed to restore the visual function. Many animal studies and some clinical trials have shown encouraging results of stem cell-based therapy in retinal degenerative diseases. While stem cell-based therapy is a promising strategy to replace damaged retinal cells and ultimately cure retinal degeneration, there are several important challenges which need to be overcome before stem cell technology can be applied widely in clinical settings. In this review, different types of donor cell origins used in retinal treatments, potential target cell types for therapy, methods of stem cell delivery to the eye, assessments of potential risks in stem cell therapy, as well as future developments of retinal stem cells therapy, will be discussed

RPE and Stem Cell Therapy

acceptedVersionPeer reviewe

Leaching and ecotoxicity tests as methods for classification and assessment of environmental hazaed of solid wastes

Doctoral thesis, Tampere University of Technology, Publication 540The importance of developing methods for the hazard assessment of solid wastes is steadily increasing worldwide. The main objective of this thesis was to develop a new approach to waste hazard classification that combines leaching and ecotoxicity tests, since the determination of total concentrations of substances in complex mixtures of unknown composition, which is a characteristic of many wastes, does not provide an accurate estimation of the overall environmental impact of solid wastes. Chemical classification was carried out by comparing total concentrations of key hazardous substances in the wastes studied with the limit values set for hazardous wastes, and comparing the leached amounts of the substances with the limit values proposed by the EU. Four wastes studied from the metal and forest industries contained predominantly inorganic compounds and ten from the furniture and resin industries mainly aromatic or aliphatic organic compounds. Six soil samples contaminated by petroleum products were studied in order to evaluate their environmental hazard after remediation. Various types of leaching tests were used to study the leaching profiles of key hazardous substances in four predominantly inorganic wastes. Onestage or multistage batch leaching tests were also used to study the leaching of volatile organic compounds from the organic wastes and that of petroleum products from the soil samples. The ecotoxicity of substances leached out from the wastes was studied from the eluates of batch leaching tests with different combinations of aquatic ecotoxicity tests: microbial tests, water flea and algal tests, electron transport assay (RET) and plant tests. In addition, the ecotoxicity of oilcontaminated soils was studied directly from solid materials with plant seed germination tests and enchytraeid worm survival and reproduction tests and the ecotoxicity of the organic wastes was investigated with a lettuce seed germination test before and after the leaching experiments. The results of the present study proved that the environmental hazard of solid wastes and soil samples was underestimated when only the total concentrations of known key hazardous substances were analyzed. It was also found that the release of these substances should be determined in order to predict the longterm environmental impacts of solid wastes. It was also important to perform an availability test on the inorganic wastes in order to ascertain their resistance to acid attack. The batch leaching tests performed on the organic wastes and contaminated soil samples studied showed that these methods should be used to screen the waterleachable fraction of the key organic compounds. The differences between the chemical and ecotoxicological classification emphasized the need for ecotoxicity tests to complement chemical analyses in the hazard classification of wastes. For example, fly ash was classified as nonhazardous by chemical analyses but ecotoxicity assays proved that the batch leaching test eluates of this waste had high or very high aquatic toxicity (10100). The organic wastes contained large amounts of compounds not identifiable with available chemical analyses. A more costeffective and relevant estimation of the overall environmental hazard of complex mixtures of unknown substances in solid wastes and their eluates could be made with a combined solidphase and liquidphase approach using ecotoxicity assays and TOC analyses. Based on the present study, the European batch leaching test method (EN124572) was proposed for the combined chemical and ecotoxicological classification of substances leached out from inorganic and organic wastes and soils. Only then can ecotoxicity test results be compared with chemical analyses to improve hazard classification when selecting the best waste management alternative. The battery of toxicity tests should consist of costeffective methods that are simple to perform, in which the volume required for analyses is minimized. According to this study, the luminescent bacteria test, MetPLATE and ToxiChromo tests, RET assay and onion root elongation test were the best choice. Wheat or lettuce seed germination tests are proposed for the determination of the ecotoxicity of solid wastes. The proposed terrestrial toxicity method for oilcontaminated soils was the Enchytraeid worm (E. albidus) survival test. This study demonstrated that environmental hazard assessment of solid wastes based only on the chemical analyses of known key hazardous substances and available regulatory values was inadequate. The results showed that the criteria for both waste classification and management could be improved by setting criteria and limit values for ecotoxicity test results. A new screening approach and criteria for the evaluation of the environmental toxicity of wastes are presented. This approach would aid environmental authorities in making decisions on waste hazard classification and help waste producers to improve their processes and minimize the environmental impacts of wastes

Composting and utilization of forest industry wastewater sludges

vokRitva Mäkelä-Kurtt

Composting of forest industry wastewater sludges for agricultural use

vo