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Adrenal gland(s)

The suprarenal or adrenal glands, each perched over one of the kidneys, are double glands. The core, or medulla, manufactures adrenalin, noradrenalin and a small amount of dopamine. The outer layer of the gland is called the cortex. The adrenal cortex produces three groups of corticosteroids; mineralocorticoids (aldosterone) - control electrolyte and water balance, glucocorticoids (cortisol)- influence carbohydrate metabolism and sex steroid hormones (androgens, DHEA). (Source: EMCOM Endocrine disruptors Glossary  )


Agency for Toxic Substances and Disease Registry

The Agency for Toxic Substances and Disease Registry (ATSDR) is an agency of the U.S. Department of Health and Human Services (HHS). As mandated by the federal superfund law, the agency assesses health risks from hazardous waste sites on the EPA's National Priorities List. ATSDR determines if additional health studies are needed at these sites, provides health advisories and publishes toxicological profiles on chemicals found at hazardous waste sites.

ATSDR also maintains exposure registries of people exposed to certain substances. (Source: ATSDR website  )

Ah receptor

Aryl hydrocarbon receptor. A protein within the cell that binds to aryl hydrocarbons forming a complex that moves into the nucleus of the cell. In the nucleus, this complex controls the onset of a series of biotransformation processes for the excretion of hydrocarbon compounds. Ah-receptor binding, may, however also result in the synthesis of other proteins, some of which may interfere adversely with cellular growth and differentiation (specialization). (Source: GreenFacts)



A protein produced by the body's immune system that recognizes and helps fight infections and other foreign substances in the body. (Source: Gift of a Lifetime Glossary  )

Aroclor 1254

Aroclor 1254 is one of several commercial PCB mixtures that were marketed between the 1930s and 70s.

This light yellow viscous liquid is a particularly highly chlorinated PCB mixture which, by definition, contains 54% chlorine by weight. (Source: Environmental Health Perspectives Differential Effects of Two Lots of Aroclor 1254  )



Bioaccumulation is used to describe the increase in concentration of a substance in an organism over time.

Bioaccumulative substances tend to be fat soluble and not to be broken down by the organism. (Source: GreenFacts )


Biologic intake

The process by which a substance crosses the outer boundary of an organism without passing an absorption barrier, e.g. through ingestion or inhalation. (Source: US EPA glossary )



The term biomagnification refers to the progressive build up of persistent substances by successive trophic levels - meaning that it relates to the concentration ratio in a tissue of a predator organism as compared to that in its prey. (Source: GreenFacts)

Blood serum

Clear, watery fluid of the blood that separates when blood clots. (Source: GreenFacts)



The dense, living tissue that makes up the skeleton of humans and vertebrate animals.

Mature bones are made up of three types of tissue: compact tissue (the hard outer portion of most bones); cancellous tissue (spongy tissue inside the bones that contains bone marrow, which makes blood cells); and subchondral tissue (smooth bone tissue of the joints).

Cancellous tissue, also known as cancellous bone, spongy bone or trabecular bone, is characterized by its spongy, porous, honeycomb-like structure and is typically found at the ends of long bones. Compact tissue is also known as hard bone, compact bone or compact cortical bone. (Source: GreenFacts)



Any one of a group of diseases that occur when cells in the body become abnormal and have the potential to spread and establish growth in nearby tissues and other parts of the body (malignancy). (Source: GreenFacts )



A capacitor is an electrical device that can store electrical energy and release it when needed. (Source: GreenFacts)



A substance, factor or situation that causes or induces cancer. (Source: GreenFacts )


The basic subunit of any living organism; the simplest unit that can exist as an independent living system. There are many different types of cells in complex organisms such as humans, each with specific characteristics. (Source: GreenFacts)


Cell membrane

The cell membrane is a fine structure that envelops a cell, separating the content of the cell from its surroundings.

It regulates the substances that can enter and leave the cell.

The membrane consists of a double layer of lipids in which proteins are embedded. (Source: GreenFacts)


Chloracne is a rare acne-like skin condition caused by exposure to halogenated aromatic hydrocarbons (such as dioxins). (Source: GreenFacts)



Chlorine (Cl2) is produced in large amounts and widely used both industrially and domestically as a disinfectant and bleach. In particular, it is widely used in the disinfection of swimming pools and is the most commonly used disinfectant and oxidant for drinking-water treatment. In water, chlorine reacts to form hypochlorous acid and hypochlorites. (Source: WHO  Guidelines for drinking water quality )


Congener is a term in chemistry that refers to one of many variants or configurations of a common chemical structure. (Source: GreenFacts)



A substance that is either present in an environment where it does not belong or is present at levels that might cause harmful effects to humans or the environment. (Source: GreenFacts)

Controlled study

An experiment or clinical trial in which two groups are used for comparison purpose.



DDT is a colourless chemical pesticide that was widely used in the 1940s and 1950s to destroy disease-carrying, crop-eating insects. It was found to be toxic to animals and humans and banned by many countries since the 1970s because of its persistence in the environment and accumulation along the food chain. (Source: GreenFacts)

Digestive tract

The digestive tract is the system of organs which takes in food, digests it to extract energy and nutrients and expels remaining waste. It includes the mouth, salivary glands, esophagus, stomach, pancreas, liver, gallbladder, small intestine, large intestine, and rectum.

After food is chewed and swallowed, the digestive juices released by the pancreas and stomach break it down into substances that are readily absorbed through the small intestine. Material that is not taken up by the body collects in the large intestine, forming faecal matter that is then excreted through the anus. (Source: GreenFacts)



"Dioxins" refers to a group of chlorinated organic chemicals with similar chemical structures.

In all GreenFacts publications the term "dioxins" is used to cover both polychlorinated dibenzo-dioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs). Other sources may refer to these compounds as "dioxins and furans".

Some dioxins have harmful properties, depending on the number and position of chlorine atoms. One of the most toxic dioxin is known as TCDD (2,3,7,8 tetrachlorodibenzo-p-dioxin). Some PCBs which have similar properties are considered "dioxin-like". (Source: GreenFacts)



Chlorinated chemicals with comparable structural and biochemical properties to dioxins. There are 12 PCBs that are considered dioxin-like. (Source: GreenFacts)


Dopamine is a chemical substance produced in the body to transmit signals between nerve cells. It is found in parts of the brain responsible for the regulation of movement, balance and walking as well as those involved in memory and learning.


Dose-response relationship

The relationship between the amount of exposure [dose] to a substance and the resulting changes in body function or health (response). (Source: ATSDR Glossary of Terms  )


Electric transformer

An electrical device used to raise or lower the voltage of alternating current. For instance, power is transported over long distances in high voltage power lines and then transformers lower the voltage so that the power can be used by household appliances. (Source: GreenFacts)

Endocrine disruptor(s)

A natural or man-made chemical that can interfere with endocrine glands and their hormones or where the hormones act - the target tissues. (Source: GreenFacts)


Environmental Health Perspectives

"The mission of Environmental Health Perspectives (EHP), the journal of the National Institute of Environmental Health Sciences, is to serve as a forum for the discussion of the interrelationships between the environment and human health by publishing in a balanced and objective manner the best peer-reviewed research and most current and credible news of the field."


A protein that encourages a biochemical reaction, usually speeding it up. Organisms could not function if they had no enzymes. (Source: NHGRI NHGRI Talking Glossary of Genetic Terms  )


Primary female sex hormone produced mainly by the ovaries. Estrogens are also produced in smaller amounts in the testes of men.

In women, estrogens are primarily involved with the development of female sexual characteristics and the maintenance of the reproductive system and menstrual cycle.

Estrogens are also thought to be important in the development of nerve cells and in the maintenance of a healthy heart.


European Commission

"The European Commission (EC) embodies and upholds the general interest of the [European] Union and is the driving force in the Union's institutional system. Its four main roles are to propose legislation to Parliament and the Council, to administer and implement Community policies, to enforce Community law (jointly with the Court of Justice) and to negotiate international agreements, mainly those relating to trade and cooperation."

The Commission's staff is organised into 36 Directorates-General (DGs) and specialised services, such as the Environment DG and the Research DG. (Source: EC website  )


Contact of the cells of an organism with a substance, micro-organism or radiation. In the case of humans, this may involve contact with a substance or agent by swallowing, breathing, or through the skin or eyes. Exposure may be short-term [acute exposure], of intermediate duration, or long-term [chronic exposure].

Exposure can be divided into external and internal.

External exposure refers to the whole dose to which an organism is exposed.

Internal exposure refers only to that fraction of the initial chemical dose that is absorbed and distributed throughout the body via systemic circulation. (Source: GreenFacts)


EXtension TOXicology NETwork

"The EXTension TOXicology NETwork (EXTOXNET) is an effort of University of California, Davis, Oregon State University, Michigan State University, Cornell University, and the University of Idaho.

Some of the goals of EXTOXNET are to stimulate dialog on toxicology issues, develop and make available information relevant to extension toxicology, and facilitate the exchange of toxicology-related information in electronic form, accessible to all with access to the Internet.

The EXTOXNET InfoBase is accessible via the World Wide Web (WWW)." (Source: EXTOXNET website )


The physiological reproductive capacity of an organism or population, i.e. its potential ability to produce viable offspring.

Not to be confused with fertility.

Confusing language difference:

Please note that "fecundity" corresponds to "fertilité" in French and "fertilidad" in Spanish whereas the French word "fécondité" and the Spanish word "fecundidad" mean "fertility". (Source: GreenFacts)


The ability of people or animals to produce healthy offspring in abundance.

Unlike fecundity, which measures a potential ability, fertility measures the actual number of offspring of an individual, a couple, a group or a population. It is evaluated by the time to achieve pregnancy.

Please note that "fertility" corresponds to "fécondité" in French and "fecundidad" in Spanish whereas the French word "fertilité" and the Spanish word "fertilidad" mean "fecundity". (Source: GreenFacts)

Flame retardant

A flame retardant is a chemical substance that is added to materials during their manufacturing process in order to both reduce the likelihood of the finished product catching fire and slow down combustion. (Source: GreenFacts)



The embryo is referred to as a foetus after it has reached a certain stage of organ development (in humans this is eight weeks after conception). (Source: CSIRO Glossary of terms  )

Food web

The interconnected food chains (feeding relationships) in an ecosystem. Plants, herbivores, and carnivores all form parts of the food web. (Source: GreenFacts)



The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein. (Source: NHGRI Talking Glossary of Genetic Terms  )

Glucuronic acid

Glucuronic acid (C6H10O7), a derivative of glucose, is produced in the liver of humans and most animals. It is a highly soluble compound that can bind to substances such as hormones, drugs, and toxins to facilitate their transport around the body. In this way glucuronic acid is largely responsible for the elimination of poisonous substances such as PCBs. (Source: GreenFacts)


Glutathione is a molecule consisting of 3 amino acids that is produced in the liver. In addition to assuring the smooth functioning of metabolic processes, it has a protective role in the cells of humans and of most animal and plant. Glutathione is an important antioxidant, meaning that it can bind to toxic substances and lead to their excretion from the body through urine or bile. (Source: GreenFacts)


The location and environmental conditions in which a particular organism normally lives. (Source: MA  Glossary )

Half life

The term which is used for the time required for the amount of a particular substance to be reduced to one half of its value when the rate of decay is exponential.

Radioactive half-life refers to the decay of radioactive substances. Iodine-131, for instance, has a half-life of 8 days whereas that of Plutonium-239 is more than 23 000 years.

Biological half-life refers to decay by biological processes. Substances with a long biological half-life will tend to accumulate in the body and are, therefore, particularly to be avoided. Substances with a short biological half-life may accumulate if some becomes tightly bound, even if most is cleared from the body rapidly. There is also the possibility of cumulative effects of chemicals which have a short residence time in the body. (Source: GreenFacts)


Health canada

"Health Canada is the federal department responsible for helping the people of Canada maintain and improve their health ."

"In partnership with provincial and territorial governments, Health Canada provides national leadership to develop health policy, enforce health regulations, promote disease prevention and enhance healthy living for all Canadians."

See also the Health Canada Environment page:  (Source: Health Canada website )

Heat transfer fluid

Any gas or liquid specifically manufactured for the purpose of transmitting heat from one system to another.

A coolant for instance is a fluid that flows through a device in order to prevent its overheating, such as water cooling down a car engine.

In a solar collector, a heat transfer fluid heats up in the collector under the effect of the sun and then flows through a heat exchange to warm a separate tank of water providing hot water for domestic use or for heating a building. (Source: GreenFacts)

Heavy metals

Metallic elements with high atomic weights, e.g. mercury, chromium, cadmium, arsenic, and lead.

They can damage living things at low concentrations and tend to accumulate in the food chain. (Source: US EPA Drinking Water Glossary  )


Chemical messengers that help our body do different tasks. Hormones are produced by the endocrine glands and then sent all over the body to stimulate certain activities. For example, insulin is a well-known hormone that helps our body digest food. Hormones regulate our growth, digestion, reproduction and sexual function. (Source: EMCOM Endocrine disruptors glossary  )

Immune system

The immune system is a network of cells, tissues, and organs that work together to defend the body against attacks by “foreign” invaders. (Source: NIAID Immune System   )



A process or substance, such as a drug, a hormone or a virus, that reduces the functioning of the immune system, lowering the body’s ability to fight infection. (Source: GreenFacts)

In vitro

In an artificial environment outside a living organism or body. For example, some toxicity testing is done on cell cultures or slices of tissue grown in the laboratory, rather than on a living animal. (Source: ATSDR Glossary of Terms  )

In vivo

Within a living organism or body. For example, some toxicity testing is done on whole animals, such as rats or mice. (Source: ATSDR Glossary of Terms  )

International Programme on Chemical Safety

The International Programme on Chemical Safety (IPCS) was established in 1980 by the WHO, the UNEP and the ILO (International Labour Organisation) "for the early warning and prevention of harmful effects of chemicals to which humans were being increasingly exposed, and for the assessment of the potential risks to human health."

It has collaborated to and published many highly recognized scientific publications.

Most publications are availaible from the INCHEM website, "a means of rapid access to internationally peer reviewed information on chemicals commonly used throughout the world, which may also occur as contaminants in the environment and food." Publications include:

International Union of Pure and Applied Chemistry

"The International Union of Pure and Applied Chemistry (IUPAC) serves to advance the worldwide aspects of the chemical sciences and to contribute to the application of chemistry in the service of Mankind. As a scientific, international, non-governmental and objective body, IUPAC can address many global issues involving the chemical sciences."


Chemical compound that has the same molecular formula - the same number and kinds of atoms - as another compound, but a different structural arrangement of the atoms in space, and, therefore, different properties.

For example, graphite (pencil lead) and diamond are isomers of carbon. Both are composed of pure carbon, but have very different physical properties.

As the number of carbon atoms in a molecule increases, the number of possible combinations, or isomers, increases sharply. For example, octane, an 8-carbon-atom molecule, has 18 isomers; decane, a 10-carbon-atom molecule, has 75 isomers. (Source: GreenFacts)



In female mammals, lactation refers to the production of milk in the mammary glands for the offspring. In humans, it is referred to as breastfeeding. (Source: GreenFacts)


A site where household and industrial waste can be disposed of. It is generally spread in thin layers which are then covered with soil. (Source: GreenFacts)


Lowest Observed Adverse Effect Level

The lowest tested dose of a substance that has been reported to cause harmful (adverse) health effects on people or animals. (Source: ATSDR glossary  )



An oily or slippery substance used to reduce the friction and/or the wear between two surfaces in relative motion, for instance in engines or door hinges. (Source: GreenFacts)

Lymphatic system

The tissues and organs that produce, store, and carry white blood cells that fight infections and other diseases.

This system includes the bone marrow, spleen, thymus, lymph nodes [small glands found along the vessels of the lymphatic system that filter out bacteria and other toxins, as well as cancer cells], and lymphatic vessels (a network of thin tubes that carry lymph and white blood cells). Lymphatic vessels branch, like blood vessels, into all the tissues of the body. (Source: NCI Dictionary of Cancer Terms  )



Cancer that begins in cells of the immune system (the lymphatic system).

The most common type of lymphoma is called Hodgkin's lymphoma or Hodgkin's disease.

All other lymphomas are grouped together under the term non-Hodgkin's lymphoma. (Source: GreenFacts)

Mammary glands

The milk-producing glands of female mammals. These glands typically begin secreting milk when young are born.

Rudimentary mammary glands are generally also found in males, but they cease development well before puberty. (Source: GreenFacts)


Mass (weight) Units

The Metric System of Measurements uses the mass units: gram (g), kilogram (kg) and tonne (t).

1000 g = 1 kg
1000 kg = 1 tonne

Adding prefixes of the International System of Units (SI) allows to express weight as multiples or fractions of 1 gram:

1 gigatonne (Gt) =1 000 000 000 000 000 g
1 megatonne (Mt) =1 000 000 000 000 g
1 tonne (t) =1 000 000 g
1 kilogram (kg) =1 000 g
1 gram (g) =1 g
1 milligram (mg) =0.001 g
1 microgram (µg) =0.000 001 g
1 nanogram (ng) =0.000 000 001 g
1 picogram (pg) =0.000 000 000 001g

Imperial and US weight units can also be expressed as metric units:

Metric units
1 US ton (ton) =0.907 tonne
1 UK ton (ton) =1.016 tonne
1 lb (pound) =453.59 g
1 oz (ounce) =28.35g

Further information on the International System of Units (SI) is provided by the International Bureau of Weights and Measures (BIPM) 


The conversion or breakdown of a substance from one form to another by an enzyme. (Source: GreenFacts, based on ATSDR Glossary of Terms )



A substance that is the product of biological changes to a chemical. (Source: US EPA Glossary  )



Any living organism that is too small to be seen by the naked eye such as bacteria, viruses, protozoa, single-celled algae, and many types of fungi. (Source: GreenFacts)


A molecule is the smallest part of any chemical compound composed of two or more atoms and which has the qualities of that substance and can exist alone in a free state. As an example, a molecule of water (H2O) consists of two atoms of hydrogen and one of oxygen. (Source: GreenFacts, based on Helios Glossary   )

Neurological effects

Effects to nervous system especially regarding structure, functions, and abnormalities. (Source: GreenFacts)


Of, or relating to, nerves and the muscles they stimulate. (Source: Science@NASA NASA neurolab Glossary  )

No Observed Adverse Effect Level

The highest tested dose of a substance that has been reported to have no harmful (adverse) health effects on people or animals. (Source: ATSDR Glossary of Terms   )



The term organic has different meanings (depending on the context):

In chemistry, "organic" refers to a chemical compound based on a hydrocarbon, i.e. a chain or a ring of carbon atoms onto which hydrogen atoms are bonded.

In agriculture, "organic" refers to a production system that excludes or limits the use of chemicals



Ozone is a form of oxygen having the molecular form of O3. It is a bluish, unstable gas with a pungent odour, found in two parts of the atmosphere: the stratosphere and the troposphere.

The ozone layer: The stratosphere contains a layer in which the concentration of ozone is greatest, the so called ozone layer. The layer extends from about 12 to 40 km. It shields the Earth from ultraviolet radiation's harmful health effects on humans and the environment. This layer is being depleted by human emissions of chlorine- and bromine-containing compounds.

Ground-level ozone: At ground level (in the troposphere), ozone is considered an air pollutant that can seriously affect the human respiratory system. It is a chemical oxidant and a major component of photochemical smog. (Source: GreenFacts)


Parkinson's disease

A progressive neurodegenerative disease characterized by impaired control of movement attributable to the death of nerve cells in a specific area of the brain.

Parkinson patients lack the neurotransmitter dopamine and experience symptoms such as tremors, muscular rigidity, difficulty in initiating motor activity, and speech impediments. (Source: GreenFacts)

Particulate matter

Sum of all microscopic solid and liquid particles, of human and natural origin, that remain suspended in a medium such as air for some time. These particles vary greatly in size, composition, and origin, and may be harmful.

Particulate matter may be in the form of fly ash, soot, dust, fog, fumes etc. (Source: GreenFacts)



Polychlorinated biphenyls (PCBs) are a family of 209 congeners of structurally similar organic chemicals, ranging from oily liquids to waxy solids. There are 12 PCBs that are dioxin-like and can similarly be toxic and non-toxic. One dioxin-like PCB is 3,4,4',5-Tetrachlorobiphenyl.

PCBs are synthetic and produced either as a singular congener, as a homogeneous group or as a mixture. They are non-flammable, stable, have a high boiling point and exhibit electrical insulating properties. As such, PCBs have been used as coolants and lubricants in transformers and other electrical equipment, as hydraulic fluids, and as plasticizers, pigments, dyes and carbonless copy paper ink. They are also generated and released into the environment as waste byproducts of chemical manufacturing and incineration. (Source: GreenFacts)


Persistent organic pollutants

Persistent organic pollutants (POPs) are chemical substances that persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effects to human health and the environment. This group of priority pollutants consists of pesticides (such as DDT), industrial chemicals (such as polychlorinated biphenyls, PCBs) and unintentional by-products of industrial processes (such as dioxins and furans).

Persistent Organic Pollutants are transported across international boundaries far from their sources, even to regions where they have never been used or produced. (Source: European Commission Environment DG POPs  )


A toxic chemical product that kills harmful organisms (e.g., insecticides, fungicide, weedicides, rodenticides, acaricides). (Source: FAO Glossary of biotechnology & genetic engineering  )



pH is a measure of the concentration of protons (H+) in a solution and, therefore, its acidity or alkalinity. The concept was introduced by S.P.L. Sørensen in 1909. The p stands for the German "Potenz", meaning power or concentration, and the H for the hydrogen ion (H+). In layman's terms , the "pH" value is an approximate number between 0 and 14 that indicates whether a solution is acidic (pH < 7), basic (pH > 7) or neither (pH = 7) [neutral]. (Source: GreenFacts )


Phenyl ring

Functional chemical group with the formula C6H5 where the six carbon atoms are arranged in a ring.

The phenyl group is simply a benzene ring with one hydrogen atom removed and is always attached to something else. (Source: GreenFacts)



A plasticiser is a substance which when added to a material, usually a plastic, produces a product which is flexible, resilient and easier to handle. (Source: Plasticisers Information Centre Frequently Asked Questions )



A group or number of people living within a specified area or sharing similar characteristics (such as occupation or age). (Source: ATSDR Glossary of Terms  )



A molecule on the surface of a cell that serves as a recognition or binding site for antigens, antibodies or other cellular or immuniologic components. (Source: NIAID HIV vaccine Glossary   )


Any substance that is used to fill or close small gaps and cracks in another material. (Source: GreenFacts )

Skin cancer

A tumour that grows from skin cells and which can have different causes, including repeated severe sunburns or long-term exposure to the sun. (Source: GreenFacts, based on EcoHealth; Glossary   )



A substance is soluble if it dissolves in certain fluids. The fluid [gas or liquid] (present in excess) is called the solvent and the substance dissolved in it is called the solute which together form a solution. The process of dissolving is called solvation. A solution that can not hold any more solute is said to be saturated. (Source: GreenFacts )


Carbon dust that is emitted into air as a result of incomplete fuel combustion. (Source: GreenFacts)



A group of organisms that differ from all other groups of organisms and that are capable of breeding and producing fertile offspring. This is the smallest unit of classification for plants and animals. (Source: OceanLink Glossary of Common Terms and Definitions in Marine Biology  )



An organ that is part of the immune system. The spleen is a storage site for lymphocytes (white blood cells important in immunity and defense against infection), it filters the blood, stores blood cells, and destroys old blood cells.

It is located on the left side of the abdomen near the stomach.

Immune reactions can occur in the spleen. (Source: GreenFacts, based on St. Jude Children’s Research Hospital Medical terminology & drug database  )


Surface water

Water on the surface of the Earth, such as in lakes, rivers, streams, ponds, and springs. (Source: ATSDR Glossary of Terms   )


The likelihood of producing a significantly larger-than-average response to a specified exposure to a substance.


Thyroid gland

The thyroid gland consists of two bodies like small walnuts; they are connected by an isthmus beside the larynx (voice box). The thyroid gland produces thyroid hormones T3 and T4 which regulate the metabolism of all cells in the body. Disorders of the thyroid gland are characterized by the inability to produce or release sufficient thyroid hormones (hypothyroidism) or the overactivity of the thyroid gland (hyperthyroidism). (Source: EMCOM Endocrine Disruptors Glossary  )



A group of cells joined to perform a set of functions. (Source: GreenFacts)

Tolerable Daily Intake

A TDI is an estimate of the amount of a substance in air, food or drinking water that can be taken in daily over a lifetime without appreciable health risk. TDIs are calculated on the basis of laboratory toxicity data to which uncertainty factors are applied.

TDIs are used for substances that do not have a reason to be found in food (as opposed to substances that do, such as additives, pesticide residues or veterinary drugs in foods- see ADI). (Source: GreenFacts)



Able to poison or harm an organism. Toxic substances can cause adverse health effects. (Source: GreenFacts)


An abnormal mass of tissue resulting from uncontrolled and excessive cell division.

Tumours can be either benign (localised, without the invasion of other tissues) or malignant (showing progressive invasion of other tissues). (Source: GreenFacts)

Uncertainty factor

A number (equal or greater than 1) used to divide NOAEL or LOAEL values derived from measurements in animals or small groups of humans, in order to estimate a NOAEL or LOAEL value for the whole human population; also called margin-of-safety. (Source: IPCS )


United Nations Environment Programme

"The United Nations Environment Programme (UNEP), established in 1972, works to encourage sustainable development through sound environmental practices everywhere. Its activities cover (...) the promotion of environmental science and information, to an early warning and emergency response capacity to deal with environmental disasters and emergencies."

See also UNEP.Net , which "delivers authoritative environmental information from a broad range of information and data providers (...)". (Source: UNEP website )

US Environment Protection Agency

The Environment Protection Agency's of the USA was founded in 1970. It's "mission is to protect human health and to safeguard the natural environment — air, water, and land — upon which life depends."

The EPA enforces federal environmental protection laws. It registers and regulates pesticides, enforces laws covering outdoor air and drinking water quality and regulates the disposal of hazardous and solid wastes.

It has now grown into a big and powerful administration: "18,000 people in Headquarters program offices, 10 regional offices, and 17 labs across the country, EPA employs a highly educated, technically trained staff, more than half of whom are engineers, scientists, and environmental protection specialists. A large number of employees are legal, public affairs, financial, and computer specialists."

U.S. EPA's scientific publications are widely recognized as reference materials. (Source: US EPA website  )

World Health Organization

"The World Health Organization  (WHO) is the directing and coordinating authority on international health within the United Nations’ system. WHO experts produce health guidelines and standards, and help countries to address public health issues. WHO also supports and promotes health research. Through WHO, governments can jointly tackle global health problems and improve people’s well-being.

193 countries and two associate members are WHO’s membership. They meet every year at the World Health Assembly in Geneva to set policy for the Organization, approve the Organization’s budget, and every five years, to appoint the Director-General. Their work is supported by the 34-member Executive Board, which is elected by the Health Assembly. Six regional committees focus on health matters of a regional nature."

WHO's scientific publications are widely recognized as a reference source.

The WHO has a number of regional offices which address the specific issues of those regions.

WHO World Regional Offices
  WHO African Region  (46 countries)
  WHO European Region  (53 countries)
  WHO Eastern Mediterranean Region  (21 countries)
  WHO Region of the Americas  (35 countries)
  WHO South-East Asia Region  (11 countries)
  WHO Western Pacific Region  (27 countries)

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