Lexikon

a quantitaive value characterising risk. The risk of chemical substances is characterised by the Risk Quotient RQ the ratio of their Predicted Environmnetal Concentration PEC and their Predicted No Effect Concentration PNEC.

The level of harm according to the risk value is the following:

acetylcholinesterase is an enzyme present in nerve tissue, muscles and red blood cells that catalyzes the hydrolysis of acetylcholine (a neurotransmitter)to choline and acetic acid, allowing neural transmission across synapses to occur.

The inhibition of acethylcholinesterase by an acetylcholinesterase inhibitor substance results in an increase in the level and life-time of acethylcholin in the neuromuscular junction resulting in prolonged muscle contraction.

The compound or group of compounds of acetylcholinesterase inhibitor (e.g., organophosphorus compounds) block the action of the enzyme acetylcholinesterase.

In luck of cholinestherase the repeated and unchecked firing of electrical signals can cause uncontrolled, rapid twitching of some muscles, paralyzed breathing, convulsions, and in extreme cases, death. Workers, farmers, gardeners using this kind of pesticides should use protective wear and tools not to be in contacts with the pesticide through skin or eye or swallowing.

Based on this activity acetylcholinesterase inhibitors are used as pesticides. Any pesticide that can bind, or inhibit, cholinesterase, making it unable to breakdown acetylcholine, is called a "cholinesterase inhibitor," or "anticholinesterase agent." The two main classes of cholinesterase inhibiting pesticides are the organophosphates (OPs) and the carbamates (CMs). Some newer chemicals, such as the chlorinated derivatives of nicotine can also affect the cholinesterase enzyme.

Organophosphate insecticides include some of the most toxic pesticides. They can enter the human body through skin absorption, inhalation and ingestion. They can affect cholinesterase activity in both red blood cells and in blood plasma, and can act directly, or in combination with other enzymes, on cholinesterase in the body. The following list includes some of the most commonly used OPs:

• acephate (Orthene)
• Aspon
• azinphos-methyl (Guthion)
• carbofuran (Furadan, F formulation)
• carbophenothion (Trithion)
• chlorfenvinphos (Birlane)
• chlorpyrifos (Dursban, Lorsban)
• coumaphos (Co-Ral)
• crotoxyphos (Ciodrin, Ciovap)
• crufomate (Ruelene)
• demeton (Systox)
• diazinon (Spectracide)
• dichlorvos (DDVP, Vapona)
• dicrotophos (Bidrin)
• dimethoate (Cygon, De-Fend)
• dioxathion (Delnav)
• disulfoton (Di-Syston)
• EPN
• ethion
• ethoprop (Mocap)
• famphur
• fenamiphos (Nemacur)
• fenitrothion (Sumithion)fensulfothion (Dasanit)
• fenthion (Baytex, Tiguvon)
• fonofos (Dyfonate)
• isofenfos (Oftanol, Amaze)
• malathion (Cythion)
• methamidophos (Monitor)
• methidathion (Supracide)
• methyl parathio
• mevinphos (Phosdrin)
• monocrotophos
• naled (Dibrom)
• oxydemeton-methyl(Meta systox-R)
• parathion (Niran, Phoskil)
• phorate (Thimet)
• phosalone (Zolonc)
• phosmet (Irnidan, Prolate)
• phosphamidon (Dimecron)
• temephos (Abate)
• TEPP
• terbufos (Counter)
• tetrachlorvinphos (Rabon, Ravap)
• trichlorfon (Dylox, Neguvon)

Carbamates, like organophosphates, vary widely in toxicity and work by inhibiting plasma cholinesterase. Some examples of carbamates are listed below:

• aldicarb (Temik)
• bendiocarb (Ficam)
• bufencarb
• carbaryl (Sevin)
• carbofuran(Furadan)
• formetanate (Carzol)
• methiocarb (Mesurol)
• methomyl (Lannate, Nudrin)
• oxamyl (Vydate)
• pinmicarb (Pirimor)
• propoxur (Baygon)

Sources:

http://extoxnet.orst.edu/tibs/cholines.htm

http://www.fluoridealert.org/westendorf.pdf

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

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

acute oral toxicity refers to those adverse effects occurring following oral administration of a single dose of a substance, or multiple doses given within 24 hours.

acute systemic toxicity testing is the estimation of the human hazard potential of a substance by determining its systemic toxicity in a test system (currently animals) following an acute exposure. Its assessment has traditionally been based on the median lethal dose (LD50) value - an estimate of the dose of a test substance that kills 50% of the test animals. For a substance to have systemic toxic effects it must be absorbed by the body and distributed by the circulation to sites in the body where it exerts toxic effects. The liver may transform a circulating drug or chemical to another form (biotransformation), and this new metabolite may be the one causing the observed toxicity.

Acute systemic toxicity is assessed following oral, dermal, and/or inhalation exposure(s) - depending upon the anticipated routes of human exposure to the substance. The Globally Harmonized System (GHS), which is scheduled for implementation in 2008, defines acute toxicity as "those adverse effects occurring following oral or dermal administration of a single dose of a substance, or multiple doses given within 24 hours, or an inhalation exposure of 4 hours"

Sources:
UNECE, 2004, p. 109.
http://www.alttox.org/ttrc/toxicity-tests/acute/

short term toxicity. The adverse effects of chemical substances which result either from a single exposure or from multiple exposures in a short space of time.
In animal testings "acute" is the toxicity, when the adverse effects occurs within 14 days of the administration of the substance. In ecotoxicity testings acute toxicity is defined as a period of time shorter, than the generation time of the testorganism. The endpoints used for the quantitative characterisation of acute toxicity are: EC₅₀, LC₅₀ or ED₅₀ and LD₅₀ values.

Acute toxicity is distinguished from chronic toxicity, which describes the adverse health effects from repeated exposures, often at lower levels, to a substance over a longer time period months or years.

acute toxicity concerns the adverse effects, which may result from a single exposure or multiple exposures within 24 hours to a substance in toxicity tests. Exposure relates to the oral, dermal or inhalation routes. Assessment of the acute toxic potential of a chemical is necessary to determine the adverse health effects that might occur following accidental or deliberate short-term exposure: the types of toxic effects, their time of onset, duration and severity, the dose-response relationships, and the sex differences in response. The investigated damages can be clinical signs of toxicity, abnormal body weight changes, and/or pathological changes in organs and tissues, which in some cases may result in death.

Source: REACH

within the context of REACH, an additive is a compond that has been intentionally added during the manufacturing process to stabilise the substance. Under other legislation additive can have other functions, e.g. pH-regulator or colouring agent.In REACH the term "additive" can also have other meanings outside the context of substance identification, for instance in relation to food or feed additives See REACH, article 2.

the integrated effect of more toxic substances, mixtures of chemical substances, xenobiotica or drogs, which can be quantified as the sum of the effects of the components, contrary to not additive effects, such as antagonism or sinergism.

an amendment-enhanced bioremediation technology for the treatment of POPs involves the creation of sequential anoxic and oxic conditions. The treatment process involves the following:

1. Addition of solid phase DARAMEND® organic soil amendment of specific particle size distribution and nutrient profile, zero valent iron, and water to produce anoxic conditions.

2. Periodic tilling of the soil to promote oxic conditions.

3. Repetition of the anoxic-oxic cycle until the desired cleanup goals are achieved.

The addition of DARAMEND® organic amendment, zero valent iron, and water stimulates the biological depletion of oxygen, generating strong reducing anoxic conditions within the soil matrix. The diffusion of replacement oxygen into the soil matrix is prevented by near saturation of the soil pores with water. The depletion of oxygen creates a low redox potential, which promotes dechlorination of organochlorine compounds. A cover may be used to control the moisture content, increase the temperature of the soil matrix and eliminate runon/run off.

The soil matrix consisting of contaminated soil and the amendments is left undisturbed for the duration of the anoxic phase of treatment cycle typically 1-2 weeks. In the oxic phase of each cycle, periodic tilling of the soil increases diffusion of oxygen to microsites and distribution of irrigation water in the soil. The dechlorination products formed during the anoxic degradation process are subsequently removed trough aerobic oxic biodegradation processes, initiated by the passive air drying and tilling of the soil to promote aerobic conditions.

Addition of DARAMEND® and the anoxic-oxic cycle continues until the desired cleanup goals are achieved. The frequency of irrigation is determined by weekly monitoring of soil moisture conditions. Soil moisture is maintained within a specific range below its water holding capacity. Maintenance of soil moisture content within a specified range facilitates rapid growth of an active microbial population and prevents the generation of leachate. The amount of DARAMEND® added in the second and subsequent treatment cycles is generally less than the amount added during the first cycle.

The additive enhanced bioremediation was successfully applied for toxaphene and DDT contaminated soil and sediment.

within the context of REACH, an additive is a compound that has been intentionally added during the manufacturing process to stabilise the substance. Under other legislation additive can have other functions, e.g. pH-regulator or colouring agent.
In REACH the term "additive" can also have other meanings outside the context of substance identification, for instance in relation to food or feed additives. (See REACH, article 2)
(Source: REACH Glossary)

ADSL= Asymmetric DSL

level of pollution, and lengths of exposure, above which adverse human health and welfare effects may occur. A prescribed level of atmospheric pollution allowed for a certain compound during a specific time in a specific geographical area. Standards are set by regulating bodies, or agencies.

algorithm is an established and well-defined step-by-step method used to achieve a desired mathematical result.

aquifer is a subsurface layer or layers of rock or other geological strata of sufficient porosity and permeability to allow either a significant flow of groundwater or the abstraction of significant quantities of groundwater

Sources of the definition: Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water, http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2000:327:0001:0072:EN:PDF

the simplest part of mathematics. Arithmetic means addition, subtraction, multiplication, and division (called operations). They are the foundation for all higher mathematics.

American Standard Code for Information Interchange

Atterberg limits are a basic measure of the nature of a fine-grained soil. Depending on the water content of the soil, it may appear in four states: solid, semi-solid, plastic and liquid. In each state the consistency and behavior of a soil is different and thus so are its engineering properties. Thus, the boundary between each state can be defined based on a change in the soil's behavior. The Atterberg limits can be used to distinguish between silt and clay, and it can distinguish between different types of silts and clays.

The shrinkage limit (SL) is the water content where further loss of moisture will not result in any more volume reduction^. The test to determine the shrinkage limit is ASTM International D4943. The shrinkage limit is much less commonly used than the liquid limit and the plastic limit.

The plastic limit (PL) is the water content where soil starts to exhibit plastic behavior. A thread of soil is at its plastic limit when it is rolled to a diameter of 3 mm or begins to crumble. To improve consistency, a 3 mm diameter rod is often used to gauge the thickness of the thread when conducting the test. (AKA Soil Snake Test)

The liquid limit (LL) is the water content where a soil changes from plastic to liquid behavior. The original liquid limit test of Atterberg's involved mixing a pat of clay in a little round-bottomed porcelain bowl of 10-12cm diameter. A groove was cut through the pat of clay with a spatula, and the bowl was then struck many times against the palm of one hand.

Derived indexes:

The plasticity index (PI) is a measure of the plasticity of a soil. The plasticity index is the size of the range of water contents where the soil exhibits plastic properties. The PI is the difference between the liquid limit and the plastic limit (PI = LL-PL). Soils with a high PI tend to be clay, those with a lower PI tend to be silt, and those with a PI of 0 tend to have little or no silt or clay.

The liquidity index (LI) is used for scaling the natural water content of a soil sample to the limits. It can be calculated as a ratio of difference between natural water content, plastic limit, and plasticity index: LI=(W-PL)/(LL-PL) where W is the natural water content.

The activity (A) of a soil is the PI divided by the percent of clay-sized particles(less than 0.075mm size) present. Different types of clays have different specific surface areas which controls how much wetting is required to move a soil from one phase to another such as across the liquid limit or the plastic limit. From the activity one can predict the dominant clay type present in a soil sample. High activity signifies large volume change when wetted and large shrinkage when dried. Soil with high activity are very reactive chemically.

Normally, activity of clay is between 0.75 and 1.25 and in this range, clay is called normal. It is assumed that the plasticity index is approximately equal to the clay fraction (A = 1). When A is less than 0.75, it is considered inactive. When it is greater than 1.25, it is considered active.

Source: Wikipedia, http://en.wikipedia.org/wiki/Atterberg_limits

community of sediment dwelling organisms, named also benthos.

also called biological diversity; the relative number of species, diverse in form and function, at the genetic, organism, community, and ecosystem level. Loss of biodiversity − one of the global environmnatel problems − reduces an ecosystem's ability to recover from natural or man-induced disruption.

Source: https://www.cia.gov/library/publications/the-world-factbook

a bit is a specific amount of information found in computers. It is abreviation of Binary Unit.

Bytes, kilobytes, megabytes and gigabytes are all increasing levels of bits. A bit is the smallest piece of computer memory. It is either 1 or 0, meaning on or off. It is exactly one-eighth.

bulk density is a property of powders, granules and other "divided" solids, especially used in reference to mineral components (soil, gravel), chemical substances, (pharmaceutical) ingredients, foodstuff or any other masses of corpuscular or particulate matter. It is defined as the mass of many particles of the material divided by the total volume they occupy. The total volume includes particle volume, inter-particle void volume and internal pore volume.

Bulk density is not an intrinsic property of a material; it can change depending on how the material is handled. For example, a powder poured in to a cylinder will have a particular bulk density; if the cylinder is disturbed, the powder particles will move and usually settle closer together, resulting in a higher bulk density. For this reason, the bulk density of powders is usually reported both as "freely settled" (or "poured" density) and "tapped" density (where the tapped density refers to the bulk density of the powder after a specified compaction process, usually involving vibration of the container.)

Sorce: http://en.wikipedia.org/wiki/Bulk_density

a bushel is a British and U.S. customary unit of dry volume, equivalent in each of these systems to 4 pecks or 8 gallons. It is used for volumes of dry (not liquid) materials, most often in agriculture. The name derives from the 14th century buschel or busschel, a box. Its conversion to other units of volume:

carcinogenic effect has a substance or a mixture of substances which induces cancer or increases its incidence and/or malignancy or shorten the time to tumour occurrence. Causing cancer may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Carcinogenic chemicals have conventionally been divided into two categories according to the presumed mode of action. Non-genotoxic modes of action include epigenetic changes, i.e., effects that do not involve alterations in DNA but that may influence gene expression, altered cell-cell communication, or other factors involved in the carcinogenic process.

Cancer is a disorder of the cells, characterized by the lack of programmed cell death. Carcinogens induces the uncontrolled, malignant division pf cells, ultimately leading to the formation of tumors. Usually DNA damage leads to programmed cell death, but if the programmed cell death pathway is damaged, then the cell cannot prevent itself from becoming a cancer cell. The objective of investigating the carcinogenicity of chemicals is to identify potential human carcinogens, their modes of action, and their potency. Once a chemical has been identified as a carcinogen, there is a need to elucidate the underlying mode of action, i.e. whether the chemical is directly genotoxic or not. For genotoxic carcinogens it is assumed that, unless exception, there is no discernible threshold and that any level of exposure carries a risk. For non-genotoxic carcinogens, no-effect-thresholds are assumed to exist and to be discernable. Human studies are generally not available for making a distinction between the above mentioned modes of action; and a conclusion on this, in fact, depends on the outcome of mutagenicity testing and other mechanistic studies. In addition to this, animal studies may also inform on the underlying mode of carcinogenic action.

The cancer hazard and mode of action may also be highly dependent on exposure conditions such as the route of exposure. Therefore, all relevant effect data and information on human exposure conditions are evaluated.

Celeron is a brand name given by Intel Corp. to a number of different x86 computer microprocessor models targeted at budget personal computers.

Read more:

Wikipedia: http://en.wikipedia.org/wiki/Celeron

CPU: http://www.cpu-world.com/CPUs/Celeron_D/

Intel: http://ark.intel.com/products/family/5263

in Annexes VII and VIII to Directive 79/831/EEC, methods for the determination of the ecotoxicity of chemical substances are enlisted. The methods are based on those recognized and recommended by competent international bodies (in particular OECD).

General introduction
1 acute toxicity for fish
2 acute toxicity for Daphnia
3 algal inhibition test
4 biodegradation: determination of the "ready" biodegradability
  4-a dissolved organic carbon (doc) die-away test
  4-b modified oecd screening test
  4-c carbon dioxide evolution test
  4-d manometric respirometry test
  4-e closed bottle test
  4-f miti test
5 degradation : biochemical oxygen demand
6 degradation: chemical oxygen demand
7 degradation: abiotic degradation: hydrolysis as a function of ph
8 toxicity for earthworms : artificial soil test
9 biodegradation: Zahn−Wellens test
10 biodegradation: activated sludge simulation test
11 biodegradation: activated sludge respiration inhibition test
12 biodegradation: modified scas test
13 bioconcentration: flow-through fish test
14 fish juvenile growth test
15 fish, short-term toxicity test on embryo and sac-fry stages
16 honeybees, acute oral toxicity test
17 honeybees, acute contact toxicity test
18 adsorption/desorption using a batch equilibrium method
19 estimation of the adsorption coefficient (koc) on soil and on sewage sludge using high performance liquid chromatography (hplc)
20 Daphnia magna reproduction test
21 soil microorganisms: nitrogen transformation test
22 soil microorganisms: carbon transformation test
23 aerobic and anaerobic transformation in soil
24 aerobic and anaerobic transformation in aquatic sediment systems

in Annexes VII and VIII to Directive 79/831/EEC, methods for the determination of the toxicity of chemical substances are enlisted. The methods are based on those recognized and recommended by competent international bodies (in particular OECD).

1 general introduction
1bis acute oral toxicity - fixed dose procedure
1tris acute oral toxicity - acute toxic class method
2 acute toxicity (inhalation)
3 acute toxicity (dermal)
4 acute toxicity: dermal irritation/corrosion
5 acute toxicity: eye irritation/corrosion
6 skin sensitisation
7 repeated dose (28 days) toxicity (oral)
8 repeated dose (28 days) toxicity (inhalation)
9 repeated dose (28 days) toxicity (dermal)
10 mutagenicity − in vitro mammalian chromosome aberration test)
11 mutagenicity − in vivo mammalian bone-marrow chromosome aberration test
12 mutagenicity mammalian erythrocyte micronucleus test
13/14 mutagenicity − reverse mutation test using bacteria
15 gene mutation − Saccharomyces cerevisae
16 mitotic recombination − Saccharomyces cerevisae
17 mutagenicity − in vitro mammalian cell gene mutation test
18 dna damage and repair − unscheduled dna synthesis − mammalian cells in vitro
19 sister chromatid exchange assay in vitro
20 sex-linked recessive lethal test in Drosophila melanogaster
21 in vitro mammalian cell transformation test
22 rodent dominant lethal test
23 mammalian spermatogonial chromosome aberration test
24 mouse spot test
25 mouse heritable translocation
26 sub-chronic oral toxicity test. Repeated dose 90-day toxicity study in rodents
27 sub-chronic oral toxicity test: repeated dose 90-day toxicity study in non-rodents
28 sub-chronic dermal toxicity test: 90-day repeated dermal dose study using rodent species
29 sub-chronic inhalation toxicity test: 90-day repeated inhalation dose study using rodent species
30 chronic toxicity test
31 teratogenicity test rodent and non-rodent
32 carcinogenicity test
33 combined chronic toxicity/carcinogenicity test
34 one-generation reproduction toxicity test
35 two generation reproduction toxicity test
36 toxicokinetics
37 delayed neurotoxicity of organophosphorus substances following acute exposure
38 delayed neurotoxicity of organophosphorus substances 28 day repeated dose study
39 unscheduled dna synthesis (uds) test with mammalian liver cells in vivo
40 skin corrosion (in vitro)
41 phototoxicity − in vitro 3t3 nru phototoxicity test
42 skin sensitisation: local lymph node assay
43 neurotoxicity study in rodents