Lexikon
nitroaromatics are carcinogenic and mutagenic aromatic substances, that are typical contaminants of contaminated military sites, e.g. 2,4,6-Trinitrotoluene (TNT), 2,4-Dinitrotoluene (DNT), 1,3,5-trinitro-1,3,5-triazine (also known as RDX), cyclotetramethylene tetranitramine (also known as HMX), some pesticides (atrazine), and a number of anilines. (Source: EUGRIS)
mature erythrocyte that lacks ribosomes and can be distinguished from immature, polychromatic erythrocytes by stains selective for ribosomes.
a change in the number of chromosomes from the normal number characteristic of the animals utilized. Used for identifying potential genotoxic substances.
occupational toxicology – sometimes also called industrial toxicology is dealing with (potential) toxic effects at workplaces on workers. Aim of occupational risk management to protect workers from physical agents and chemical substances and makes their work-environment safe. It means that it is closely related to environmental toxicology, but “environment” is restricted to the workplace: the air inside the industrial plant, the risk of dermal or eye contact of chemical substances being at work, as well as development of occupational diseases in association with the chemical substances used or produced in the technologies.
organic weed management promotes weed suppression, rather than weed elimination, by enhancing crop competition and phytotoxic effects on weeds. Organic farmers integrate cultural, biological, mechanical, physical and chemical tactics to manage weeds without synthetic herbicides.
Organic crop rotations frequently include weed-suppressive cover crops and crops with dissimilar life cycles to discourage weeds associated with a particular crop. Organic farmers strive to increase organic soil matter content, which can support microorganisms that destroy common weed seeds.
Other cultural practices used to enhance crop competitiveness and reduce weed pressure include selection of competitive crop varieties, high-density planting, tight row spacing, and late planting into warm soil to encourage rapid crop germination.
Mechanical and physical weed control practices used on organic farms can be broadly grouped as
- Tillage - turning the soil between crops to incorporate crop residues and soil amendments; remove existing weed growth and prepare a seedbed for planting;
- Cultivation - disturbing the soil after seeding;
- Mowing and cutting - removing top growth of weeds;
- Flame weeding and thermal weeding - using heat to kill weeds; and
- Mulching - blocking weed emergence with organic materials, plastic films, or landscape fabric.
Some naturally-sourced chemicals are allowed for herbicidal use. These include certain formulations of acetic acid (concentrated vinegar), corn gluten meal, and essential oils. A few selective bioherbicides based on fungal pathogens have also been developed. At this time, however, organic herbicides and bioherbicides play a minor role in the organic weed control toolbox.
Weeds can be controlled by grazing. For example, geese have been used successfully to weed a range of organic crops including cotton, strawberries, tobacco, and corn, reviving the practice of keeping cotton patch geese, common in the southern U.S. before the 1950s. Similarly, some rice farmers introduce ducks and fish to wet paddy fields to eat both weeds and insects.
the Pan-European Ecological Network (PEEN) is one of the implementation tools of the Pan-European Biological and Landscape Diversity Strategy (PEBLDS). PEEN aims to link the different European and national protected areas and ecological networks with goal of ensuring the favourable conservation status of Europe’s key ecosystems, habitats, species and landscapes.
Ecological network is a system of the most valuable sites, important for protection of threatened species, habitat types, ecological systems or landscapes. Ecological network sites must be relatively close to each other and connected with corridors, which allow them to communicate and exchange species.
Ecological networks contain four main elements:
1. Core areas: These are areas where the primary function is biodiversity conservation. They are usually legally protected under national or European legislation (e.g. Natura 2000 sites). These areas should provide a substantial representation of key natural or semi-natural ecosystems and contain viable populations of important or threatened species. Land use within these areas is managed to give priority to biodiversity conservation.
2. Corridors: These are areas of suitable habitat that provide functional linkages link between core areas. For example, they may stimulate or allow species migration between areas. Corridors can be continuous strips of land or ‘stepping stones’ that are patches of suitable habitat. Using corridors to improve ecological coherence is one of the most important tools in combating the fragmentation that is threatening so many of Europe’s habitats. Generally speaking corridors can be associated with higher levels of land use, as long as their function is maintained.
3. Buffer zones: Protected areas should not be considered as islands that are safe from negative external effects. The resource use that occurs outside them can have serious impacts on species and habitats within, for example air/water pollution from industrial activities around a protected area can have serious effects on species inside it. Buffer zones allow a smoother transition between core areas and surrounding land use. The size and utilisation of buffer zones depends heavily on the particular needs of the specific ecosystem and its local population.
4. Sustainable use areas: These are remaining areas that can come under more intensive land use. But they should still take full account of the successful provision of ecosystem goods and services.
Connecting organisations
- ECNC-http://www.ecnc.org
- IUCN Programme Office for Central Europe-http://www.iucn-ce.org
- Database of Central and Eastern European Ecological Networks
- Plantlife International - http://www.plantlife.org.uk/international/plantlife-ipas.html
- Council of Europe
- IUCN WCPA - http://www.iucn.org/themes/wcpa/
- IUCN CEM - http://www.iucn.org/themes/cem/
Source: http://www.countdown2010.net/archive/paneuropean.html
Annex XIII of REACH defines criteria for the identification of substances that are Persistent, Bio-accumulative and Toxic (PBTs) and Annex I lays down general provisions for PBT assessment. PBTs are substances of very high concern (SVHC) and may be included in Annex XIV and by that be made subject to authorisation (Source: REACH)
pharmacokinetics or toxicokinetics is "defined as the study of the rates of absorption, distribution, metabolism, and excretion of toxic substances or substances under toxicological study" (OECD). Pharmacokinetics/toxicokinetics testing involves describing "the bioavailability of a substance and its kinetic and metabolic fate within the body". Pharmacokinetics is also the term used to describe the assessment of absorption, distribution and metabolism in the context of drug preclinical testing.
Metabolism has been "defined as all aspects of the fate of a substance in an organism ..." by OECD; however, metabolism generally refers to the biotransformation of a substance (via an enzymatic or nonenzymatic process) within the body to other molecular species (usually called the metabolites). For ingested substances, metabolism primarily takes place in the liver, although many organs and tissues have metabolic capability. Two types of enzymes are involved in metabolism: phase 1 (cytochrome P450 enzyme family) and phase 2 enzymes.
An understanding of the metabolism of a substance in the body is critical to understanding its toxicity. For example, biotransformation sometimes results in a molecular species being generated that is more toxic than the original substance. The lack of metabolism of a substance can result in its bioaccumulation in the body. Understanding a substance's metabolism can also facilitate identification of possible target organs and the route of clearance.
Pharmacokinetic/toxicokinetic data may be used to:
- assist in the interpretation of other toxicological data,
- select doses for other toxicological studies, and/or
- extrapolate data from animals to the human (OECD).
Source: http://alttox.org/ttrc/toxicity-tests/pharmacokinetics-metabolism/
physical weathering is caused by the effects of changing temperature on rocks, causing the rock to break apart. The process is sometimes assisted by water.
There are two main types of physical weathering:
- Freeze-thaw occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart.
- Exfoliation occurs when minerals in the rocks are continuously heated and cooled in hot climates.
- On the effect of cristal-formation of salts or oxide formation of iron or other metals. Increased volume of these chemical componunds break the rock.
- Plnat root growth is able to break the rock too.
Physical weathering happens especially in places places where there is little soil and few plants grow, such as in mountain regions and hot deserts. Either through repeated melting and freezing of water (mountains and tundra) or through expansion and contraction of the surface layer of rocks that are baked by the sun (hot deserts).
hysico-chemical testing methods for chemical substances: COUNCIL REGULATION (EC) No 440/2008 of 30 May 2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).
(1) Pursuant to Regulation (EC) No 1907/2006, test methods are to be adopted at Community level for the purposes of tests on substances where such tests are required to generate information on intrinsic properties of substances.
(2) Council Directive 67/548/EEC of 27 June 1967 on the approximation of the laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances laid down, in Annex V, methods for the determination of the physico-chemical properties, toxicity and ecotoxicity of substances and preparations. Annex V to Directive 67/548/EEC has been deleted by Directive 2006/121/EC of the European Parliament and of the Council with effect from 1 June 2008.
(3) The test methods contained in Annex V to Directive 67/ 548/EEC should be incorporated into this Regulation.
(4) This Regulation does not exclude the use of other test methods, provided that their use is in accordance with Article 13(3) of Regulation 1907/2006.
(5) The principles of replacement, reduction and refinement of the use of animals in procedures should be fully taken into account in the design of the test methods, in particular when appropriate validated methods become available to replace, reduce or refine animal testing.
(6) The provisions of this Regulation are in accordance with the opinion of the Committee established under Article 133 of Regulation (EC) No 1907/2006
Article 1: The test methods to be applied for the purposes of Regulation 1907/2006/EC are set out in the Annex to this Regulation.
Article 2: The Commission shall review, where appropriate, the test methods contained in this Regulation with a view to replacing, reducing or refining testing on vertebrate animals.
Article 3: All references to Annex V to Directive 67/548/EEC shall be construed as references to this Regulation.
Article 4: This Regulation shall enter into force on the day following its publication in the Official Journal of the European Union.
It shall apply from 1 June 2008.
LIST OF METHODS FOR THE DETERMINATION OF PHYSICO-CHEMICAL PROPERTIES OF CHEMICAL SUBSTANCES
A.1. Melting/freezing temperature
A.2. Boiling temperature
A.3. Relative density
A.4. Vapour pressure
A.5. Surface tension
A.6. Water solubility
A.8. Partition coefficient
A.9. Flash-point
A.10. Flammability (solids)
A.11. Flammability (gases)
A.12. Flammability (contact with water)
A.13. Pyrophoric properties of solids and liquids
A.14. Explosive properties
A.15. Auto-ignition temperature (liquids and gases)
A.16. Relative self-ignition temperature for solids
A.17. Oxidising properties (solids)
A.18. Number – average molecular weight and molecular weight distribution of Polymers
A.19. Low molecular weight content of polymers
A.20. Solution/extraction behaviour of polymers in water
A.21. Oxidising properties (liquids)
PIC = Prior Informed Consent
The Rotterdam Convention on Prior Informed Consent (PIC) is a global treaty that came into force in February 2004, with the intention to protect developing countries from the import of dangerous chemicals. The PIC Convention is implemented in the EU by means of regulation concerning the export and import of dangerous chemicals. Under the proposed recast of this PIC Regulation, the companies will continue to notify to their national authorities their intention to export banned or severely restricted chemicals. ECHA will take over the task to communicate with the destination country and to keep a register of the notifications.
Source: News from ECHA, No 5, Oct 2011, http://echa.europa.eu/doc/press/newsletter/echa_newsletter_2011_5.pdf
plutonic rocks (also called intrusive igneous rocks) resulted from magmas solidified below ground. When magmas crystallize deep underground they look different from volcanic rocks because they cool more slowly and, therefore, have larger crystals. Igneous rocks cooled beneath the Earth's surface are called intrusive rocks. The intrusive equivalents of basalt, andesite, and rhyolite are gabbro, diorite, and granite, respectively. In Hungary the Velencei mountain is composed of intrusive igneous rocks such as, granodiorite and diorite and the granite block in Mórágy was formed in similar conditions.
The underground crystallization stages of the magma are the following:
A. Preliminary crystallization stage (approx. 1100–1000 °C)
During the preliminary crsystallization stage ultrabasic and basic rocks are formed. The temperature decrease results separation of the silicate and sulphide melts. The preliminary crystallization gives economically important ore deposits: chromite, magnetite, ilmenite, platina, diamond and apatite.
B. Main crystallization stage (approx. 1000–700 °C)
In the main crystallization stage the magma solidification occurs. The olivine, pyroxene, amphiboles and the feldspars crystallize in parallel and finally the quartz.
C. Post magmatic stage (from approx. 700 °C)
The volatile containing residual magma is crystallised in this phase. The post magmatic stage includes three phases:
Pegmatite phase (approx. 700–550 °C): The mineral composition of the pegmatites crystallized in this phase is identical with that of the main crystallization phase however the pegmatites contain much larger crystals. The pegmatites in general occur in veins and are rich in rare elements such as stanium, uranium, thorium, boron, lithium, berillium, zirconium, titanium, tanthal.
Pneumatolitic phases (approx. 550–375 °C): The halogene rich solutions are chemically very active and thus are able to considerably modify the solidified rocks. This phase results various minerals such as quartz, fluorite, wolframite, turmaline.
Hydrothermal phase (from approx. 375 °C): The water diluted, solutions of the residual magma penetrated the cracks, voids of the rocks forming hydrothermal veins. During the hydrothermal phase mainly the following metals are concentrated: gold, silver, copper, lead, zinc, mercury and the iron, cobalt and nickel remained still in the residual solution.
polychlorinated dibenzofurans (PCDFs) are a group of halogenated organic componunds with a furane skeleton and chlor substituents different in numer. PCDFs occur as by-products in the manufacture of chlorinated organic substances, in the incineration of chlorine-containing substances such as PVC, in the bleaching of paper, and also from natural sources such as volcanoes and forest fires. Somilar to polychlorinated dibenzodioxins (PCDDs), they have been shown to bioaccumulate in humans and and animals, are known toxic, mutagenic, carcinogenic and reprotoxic.
a polychromatic erythrocyte is an immature erythrocyte in an interstitial phase, that still contains ribosomes, so it can be distinguished from mature erythrocytes by applying selective staining.
predictable death is a term used in toxicity tests when the presence of clinical signs indicative of death at a known time in the future before the planned end of the experiment, for example: inability to reach water or food.
concentration of the substance below which adverse effects in the environmental sphere of concern are not expected to occur. PNEC is relevant for an ecosystem, e.g. aquatic or terrestrial. PNEC is generally calculated from the ecotoxicity test results of testorganisms of three different trophic levels by factorial extrapolation, using safety factors or by statistical extrapolation.
Applying factorial extrapolation the following assessment factors are applied according to uniform protocols:
f=1000: at least one short-term EC50 from each of three trophic levels,
f = 100: long-term NOEC from one trophic level besides 2 acute,
f = 50: long-term NOEC from species representing two trophic levels besides one acute,
f = 10: long-term NOEC from at least three trophic levels,
f = 1: PNEC can be directly measured in microcosms, mesocosms or ecosystem-field-testing.
Another method to determine a PNEC value is the use of statistical extrapolation methods using the variation in species sensitivity. If a large data set with NOECs from long-term experiments for different taxonomic groups is available, these values can be used to draw a distribution. This distribution that describes the variability of hazard of a substance to organisms is called a Species Sensitivity Distribution (SSD). This distribution can be presented as a frequency distribution (cumulative normal distribution curves or other similar distribution curves) of NOEC values for species. From this curve we can read Xm, the mean toxicity expressed as the mean NOEC value of a substance. The Sm represents the toxicity range or variation in sensitivity of a substance.
The main assumption on the use of SSDs in risk assessment is that the distribution based on a selection of species (tested in laboratory experiments) are representative for all species (in the field).
Statistical extrapolation methods may be used to derive a PNEC from a SSD by taking a prescribed percentile of this distribution. For pragmatic reasons it has been decided that the concentration corresponding with the point in the SSD profile below which 5% of the species occur, should be derived as an intermediate value in the determination of a PNEC. This 5% point in the SSD is also identified as a hazardous concentration (HC) at which a certain percentage (in this case 5%) of all species is assumed to be affected.
transgenic animals may be developed for a wide range of purposes. Some of the areas in which transgenic animals are important are: medical research, livestock improvement, pharming and xenotransplantation.
Pharming means the production of biologically active human proteins, diagnostics, monoclonal antobodies, and nutraceuticals.
proteomics is the study of protein molecules in the cell to find association with the composition and cellular response to toxic chemical substances. It is an innovative tool in pharmacology, toxicology and environmental toxicology.
Proteins are the primary structural and functional molecules in the cell, and are made up of a linear arrangement of amino acids. The linear polypeptide chains are folded into secondary and tertiary structures to form the functional protein. Unlike the static nature of the cell's genes, proteins are constantly changing to meet the needs of the cell.
Characterizing the identity, function, regulation, and interaction of all of the cellular proteins of an organism, the proteome, will be a major achievement. Studies of changes in the proteome of cells and tissues exposed to toxic materials, compared to normal cells, is being used to develop an understanding of the mechanisms of toxicity. As proteomics tools become more powerful and widely used, protein and proteome changes in response to exposures to toxic substances (fingerprints or response profiles) will be developed into databases that can be used to classify exposure responses at various levels of organization of the organism, thus providing a predictive in silico toxicology tool.