Lexikon

ecologists, naturalists, and other scientists collectively research and address issues pertaining to global declines in biodiversity. The conservation ethic advocates management of natural resources for the purpose of sustaining biodiversity in species, ecosystems, the evolutionary process, and human culture and society.

Conservation biology is reforming around strategic plans that include principles, guidelines, and tools for the purpose of protecting biodiversity. Conservation biology is crisis–oriented and multi–disciplinary, including ecology, social organization, education, and other disciplines outside of biology.

Preserving biodiversity is a global priority in strategic conservation plans that are designed to engage public policy and concerns affecting local, regional and global scales of communities, ecosystems, and cultures.

Action plans identify ways of sustaining human well-being, employing natural capital, market capital, and ecosystem services.

neurotoxicology is the study of the adverse effects of chemical, biological, and certain physical agents on the nervous system and/or behavior during development and in maturity. Many common substances are neurotoxic, including lead, mercury, some pesticides, and ethanol.

Neurotoxicity testing is used to identify potential neurotoxic substances. Neurotoxicity is a major toxicity endpoint that must be evaluated for many regulatory applications. Sometimes neurotoxicity testing is considered as a component of target organ toxicity; the central nervous system (CNS) being one of the major target organ systems. In utero exposure to chemicals and drugs can also exert an adverse effect on the development of the nervous system, which is called developmental neurotoxicity (DNT).

Like other target organ toxicities, neurotoxicity can result from different types of exposure to a substance; the major routes of exposure are oral, dermal, or inhalation. Neurotoxicity may be observed after a single (acute) dose or after repeated (chronic) dosing.

Source: http://alttox.org/ttrc/toxicity-tests/neurotoxicity/

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)

nitrobenzene is a water-insoluble pale yellow oil with an almond-like odor. It is produced on a large scale as a precursor to aniline. Although occasionally used as a flavoring or perfume additive, nitrobenzene is highly toxic in large quantities. In the laboratory, it is occasionally used as a solvent.

Nitrobenzene is highly toxic, mainly for blood cells and kidney, as well as for the brain. It is readily absorbed through the lung and

The summary of the UK Health Protection Agency says:

Fire hazard:

• Flammable
• Violently reacts with strong oxidants, acids and nitrogen oxides
• Emits toxic fumes of nitrogen oxides when heated to decomposition
• In the event of a fire involving nitrobenzene, use fine water and liquid tight chemical protective clothing with breathing apparatus

Health hazard:

• Toxic by inhalation, ingestion and skin absorption
• Possibly carcinogenic in humans
• May cause reproductive toxicity
• The onset of symptoms may be delayed 1-4 hours after exposure to nitrobenzene
• Inhalation can cause irritation of the respiratory tract, nausea, headache, dizziness, shortness of breath and in extreme cases could lead to coma and death
• Ingestion of nitrobenzene may cause gastrointestinal irritation with nausea, vomiting and diarrhoea, as well as symptoms similar to those for inhalation
• Inhalation and ingestion may also cause vertigo and bluish colouration of the skin due to a condition called methaemoglobinaemia, with drowsiness, high blood pressure, convulsions, anaemia, jaundice and kidney failure
• Skin contact with nitrobenzene may result in mild skin irritation and eye contact may lead to mild eye irritation

Environmental hazard::

• Dangerous for the environment
• Inform Environment Agency of substantial incidents

Prolonged exposure may cause serious damage to the central nervous system, impair vision, cause liver or kidney damage, anemia and lung irritation. Inhalation of fumes may induce headache, nausea, fatigue, dizziness, cyanosis, weakness in the arms and legs, and in rare cases may be fatal. The oil is readily absorbed through the skin and may increase heart rate, cause convulsions or rarely death. Ingestion may similarly cause headaches, dizziness, nausea, vomiting and gastrointestinal irritation, loss of limbs and also causes internal bleeding.

Nitrobenzene is considered a likely human carcinogen by the United States Environmental Protection Agency too.

Sources and further information:

http://whqlibdoc.who.int/ehc/WHO_EHC_230.pdf

http://www.hpa.org.uk/Topics/ChemicalsAndPoisons/CompendiumOfChemicalHazards/Nitrobenzene/

http://en.wikipedia.org/wiki/Nitrobenzene

nitrogen is a chemical element that has the symbol N, its atomic number is 7, its atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere.

Many industrially important compounds, such as ammonia, nitric acid, organic nitrates (propellants and explosives), and cyanides, contain nitrogen. The extremely strong bond in elemental nitrogen dominates nitrogen chemistry, causing difficulty for both organisms and industry in breaking the bond to convert the N₂ into useful compounds, but releasing large amounts of often useful energy, when these compounds burn, explode, or decay back into nitrogen gas.

Nitrogen is a biogenic element, it occurs in all living organisms. It is a constituent element of amino acids and thus of proteins, and of nucleic acids (DNA and RNA). It resides in the chemical structure of almost all neurotransmitters, and is a defining component of alkaloids, biological molecules produced by many organisms.

The global nitrogen cycle is linked to all environmental compartments: atmosphere, waters and soils. Elemental nitrogen in the atmosphere cannot be used directly by either plants or animals, specific soil bacteria are able to fix atmospheric nitrogen in the form of ammonium and used by themselves (Azotobacter) or supplied for symbiotic plants, e.g. by Rhyzobium. Plants are able to utilise nitrates (NO₃), the result of mineralisation of organic compounds by microorganisms. Many bacteria living in soils and waters biodegrade dead organic material, when organically bound nitrogen is converted into ammonia (ammonification). Nitro- and nitrosobacteria are able to oxidise ammonia into nitrite or nitrate (nitrification). Facultative anaerobic bacteria are able to reduce nitrate in the process of denitrification (basis of many water and soil biotechnologies), using nitrate for their alternative respiration (nitrate respiration), producing nitrogen gas or ammonia. Microorganisms play essential role in nitrogen-cycle.

During the hystory of Earth, N derived from evaporation of the Earth crust or from chemical reactions. N-reserve of Earth can be be found in the atmospheric air: cca. 4x10¹² tons N₂.

our sensibility for the odour of a substance is expressed as a threshold value. This is the concentration of a substance in 1 m³ air that can be detected by half of the people that are present. This is considered the unit of odour.
Examples:
- Chloroform is detected when 130 molecules are present in a million molecules of air.
- Chlorophenols can already be detected when 3 molecules are present in a hundred billion molecules of air.
Humans can differ up to a factor of a hundred thousand in their sensibility for a certain substance.

Source: http://www.lenntech.com/odour-information.htm

Personal Computer

Personal Digital Assistant

Hypertext Preprocessor

there are 16 elements that are essential nutrients for plant growth. Plants can only take those nutrients from soils if they are easily available or in specific chemical forms. Chemical, physical and biological processes contribute to the availability of these nutrients in soils. In this context, processes carried out by soil biota are important for the maintenance of crop production and good crop yields. They also contribute to plant nutrition in areas where chemical fertilizers cannot be applied. Below are some examples of how the soil biota can contribute to the formation of nutrient pools and the availability of nutrients.

Source: EUROPEAN ATLAS OF SOIL BIODIVERSITY, JRC, European Comission, 2010

the direct or indirect introduction, as a result of human activity, of substances or heat into the air, water or land which may be harmful to human health or the quality of aquatic ecosystems or terrestrial ecosystems directly depending on aquatic ecosystems, which result in damage to material property, or which impair or interfere with amenities and other legitimate uses of the environment.

CPU, Central Processing Unit in computers

Random Access Memory

Random Access Memory

repeatability is the degree to which repeated measurements under unchanged conditions show the same results.

the repeated dose toxicity comprises the general toxicological effects occurring as a result of repeated daily exposure to a substance for a part of the expected lifespan (sub-acute or sub-chronic exposure) or for the major part of the lifespan (chronic exposure).

These general toxicological effects include effects on body weight and/or body weight gain, absolute and/or relative organ and tissue weights, alterations in clinical chemistry, urinalysis and/or haematological parameters, functional disturbances in the nervous system as well as in organs and tissues in general, and pathological alterations in organs and tissues as examined macroscopically and microscopically. Besides this information on possible adverse general toxicological effects, repeated dose toxicity studies may also provide other information on e.g. reproductive toxicity or carcinogenicity or may identify specific manifestations of toxicity such as e.g., neurotoxicity, immunotoxicity, endocrine-mediated effects...

The objectives of assessing repeated dose toxicity are to evaluate:

• whether repeated exposure of humans to a substance has been associated with adverse toxicological effects; these human studies potentially may also identify populations that have higher susceptibility;
• whether repeated administration of a substance to experimental animals causes adverse toxicological effects; effects that are predictive of possible adverse human health effects;
• the target organs, the potential cumulative effects and the reversibility of the adverse toxicological effects;
• the dose-response relationship and the threshold for any of the adverse toxicological effects observed in the repeated dose toxicity studies;

Source: REACH