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The process of taking in. For a person or an animal, absorption is the process of a substance getting into the body through the eyes, skin, stomach, intestines, or lungs. (Source: ATSDR Glossary of Terms  )


Acid rain

Falling rain (or snow) which has become acidic (pH less than 5.6) as a result of its combination with gaseous pollutants, such as sulphur dioxide (SO2) and nitrogen oxides (NOx).

Acid rain may cause acidification of surface waters, soils and ecosystems. (Source: GreenFacts)



To take up and hold (a gas, liquid, or dissolved substance) in a thin layer of molecules on the surface of a solid substance. (Source: US EPA Acid Rain Glossary  )


Adverse health effect

A change in body function or cell structure that might lead to disease or health problems. (Source: ATSDR Glossary of Terms  )

Alien species

An alien species is a species introduced outside its normal distribution.

Invasive alien species are alien species whose establishment and spread modify ecosystems, habitats, or species. (Source: MA  Glossary )



Breeding and rearing of fish, shellfish, or plants in ponds, enclosures, or other forms of confinement in fresh or marine waters for the direct harvest of the product. (Source: MA   Glossary )


The mass of air surrounding the Earth.

The atmosphere consists of nitrogen (78%), oxygen (21%), and traces of other gases such as argon, helium, carbon dioxide, and ozone.

The atmosphere plays an important role in the protection of life on Earth; it absorbs ultraviolet solar radiation and reduces temperature extremes between day and night. (Source: GreenFacts)



Bacteria are a major group of micro-organisms that live in soil, water, plants, organic matter, or the bodies of animals or people. They are microscopic and mostly unicellular, with a relatively simple cell structure.

Some bacteria cause diseases such as tetanus, typhoid fever, pneumonia, syphilis, cholera, and tuberculosis.

Bacteria play a role in the decomposition of organic matter and other chemical processes. (Source: GreenFacts)



Bottom dwelling; living on or under the sediments or other substrate [in an aquatic system].



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 )



Biodiversity is a contraction of biological diversity. Biodiversity reflects the number, variety and variability of living organisms.

It includes diversity within species (genetic diversity), between species (species diversity), and between ecosystems (ecosystem diversity). (Source: GreenFacts)



Biofilms are communal structures of micro-organisms that adhere to living or inert surfaces and are encased in a protective coating secreted by them.

Bacteria living as a biofilm are able to resist to biocides and to antibiotics more effectively than those living as free organisms and they withstand considerably higher doses of antimicrobial products. (Source: GreenFacts)


Any technological application that uses biological systems, living organisms, or derivatives thereof to make or modify products or processes for specific use. (Source: MA  Glossary )


Capacity building

A process of strengthening or developing human resources, institutions, organizations, or networks.

Also referred to as capacity development or capacity enhancement. (Source: MA,  Glossary )


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)

Circulatory system

The system that contains the heart and the blood vessels and moves blood throughout the body. This system helps tissues get enough oxygen and nutrients, and it helps them get rid of waste products. The lymph system, which connects with the blood system, is often considered part of the circulatory system. (Source: NCI Dictionary of cancer terms  )


Climate change

The long-term fluctuations in temperature, precipitation, wind, and all other aspects of the Earth's climate.

It is also defined by the United Nations Convention on Climate Change as “change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods” (Source: CoRIS glossary  )


A material made up of two or more elements combined in a fixed ratio. (Source: CoRIS glossary  )


Cost-benefit analysis

A type of economic evaluation in which both the costs and consequences of different interventions are expressed in monetary units. (Source: CiREM Definitions  )



The conversion of forested land to non-forested land as a direct result of human activities. (Source: Forest Carbon Accounting Definitions  )



A delta is a low, watery land formed at the mouth of a river.

It is formed from the silt, sand and small rocks that flow downstream in the river and are deposited in the delta.

A delta is often (but not always) shaped like a triangle. (Source: NY Geography Glossary  )



To desorb is to remove a gas, liquid, or dissolved substance from a surface on which it is adsorbed. (Source: GreenFacts)


Ecosystem services

The benefits people obtain from ecosystems.

These include provisioning services such as food and water; regulating services such as flood and disease control; cultural services such as spiritual, recreational, and cultural benefits; and supporting services such as nutrient cycling that maintain the conditions for life on Earth. (Source: MA  Summary )



The complex system of plant, animal, fungal, and microorganism communities and their associated non-living environment interacting as an ecological unit.

Ecosystems have no fixed boundaries; instead their parameters are set to the scientific, management, or policy question being examined. Depending upon the purpose of analysis, a single lake, a watershed, or an entire region could be considered an ecosystem. (Source: US EPA Glossary of Climate Change Terms   )

Elemental mercury

Hg. Mercury in its elemental (pure) form, that is, as a metal; hence the synonym metallic mercury. A shiny, silver-gray metal that is a liquid at room temperature. (Source: GreenFacts)



The increase in additions of nutrients [especially nitrogen and phosphorus] to freshwater or marine systems, which leads to increases in plant growth and often to undesirable changes in ecosystem structure and function. (Source: MA  Glossary )



Feedstock refers to the raw material that is required for some industrial process. (Source: GreenFacts )


Food web

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



Water that is not salty, for instance water found in lakes, streams, and rivers, but not the ocean. Also used to refer to things living in or related to freshwater (e.g., "freshwater fish"). (Source: GreenFacts)



Any of a group of plant-like microorganisms that include molds, mildews, mushrooms and yeast.

Fungi lack chlorophyll and use living or dead organisms as food by breaking them down and then absorbing the substances into their cells. Many fungi reproduce by disseminating spores which are transported by air and await proper conditions of moisture and temperature to germinate, grow and reproduce. (Source: GreenFacts )

Global scale

The geographical realm encompassing all of Earth. (Source: MA  Glossary )

Greenhouse gas

Greenhouse gases are those gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of infrared radiation emitted by the Earth’s surface, the atmosphere and clouds.

This property causes the greenhouse effect.

Water vapour (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4), and ozone (O3) are the primary greenhouse gases in the Earth’s atmosphere. Moreover there are a number of entirely human-made greenhouse gases in the atmosphere, such as the halocarbons and other chlorine and bromine containing substances, dealt with under the Montreal Protocol. Beside CO2, N2O and CH4, the Kyoto Protocol deals with the greenhouse gases sulphur hexafluoride (SF6), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs). (Source: IPCC Glossary  )

Human health

A state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.

The health of a whole community or population is reflected in measurements of disease incidence and prevalence, age-specific death rates, and life expectancy. (Source: MA Glossary  )

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  )


Inflammation is the reaction of living tissues to infection, irritation or other injury. (Source: GreenFacts)



The act of swallowing something through eating, drinking, or mouthing objects. A hazardous substance can enter the body this way. (Source: ATSDR Glossary of Terms  )


Any animal lacking an internal skeleton such as a backbone or spinal column. Examples of invertebrates include worms, insects, oysters, and crabs.

The group includes all animals except fish, reptiles, amphibians, birds and mammals. (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)



An essential structural component of living cells, lipids are a class of oily organic compounds which are insoluble in water but soluble in fats and oils. The lipid class of molecules mainly consists of fats, oils and waxes. (Source: GreenFacts)



Mathematical representation or simulation of an actual situation. (Source: GreenFacts)


Mollusks are a large group of soft-bodied invertebrates that are widespread in salt water, freshwater, and terrestrial habitats. Examples of mollusks include snails, clams, squids, octopus, and cuttlefish.

Most mollusks have a muscular foot and a hard, calcareous outer shell protecting their soft body, but some, as in the squid and octopus, lack this type of shell. (Source: GreenFacts)



Death. Usually the cause (a specific disease, a condition, or an injury) is stated. (Source: ATSDR Glossary of Terms   )

Natural organic matter

Organic matter originating from plants and animals present in natural (untreated or raw) waters, for example, in lakes, rivers and reservoirs. (Source: GreenFacts)



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)



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  )


Polycyclic aromatic hydrocarbons

A group of over 100 different organic compounds composed of several benzene rings. Some of them are persistent and carcinogenic.

PAHs are commonly formed during the incomplete burning of coal, oil and gas, garbage, or other organic substances like tobacco or charbroiled meat.

Generally, tobacco smoke is by far the most important source of exposure for humans. (Source: GreenFacts)



A polymer is a high-molecular-weight organic compound, natural or man-made, consisting of many repeating simpler chemical units or molecules called monomers.

Examples of natural polymers are proteins (polymer of amino acids) and cellulose (polymer of sugar molecules).

An example of synthetic polymer is PVC (a polymer of vinyl chloride). (Source: GreenFacts)



Energy moving in the form of particles or waves. Familiar radiations are heat, light, radio waves, and microwaves. Ionizing radiation is a very high-energy form of electromagnetic radiation. (Source: US Center for Disease Control and Prevention Glossary of Radiological Terms   )



The probability that something will cause injury or harm. (Source: ATSDR Glossary of Terms  )


A measure of the salt concentration of water. (Source: CoRIS Glossary  )


A portion or piece of a whole. A selected subset of a population or subset of whatever is being studied. For example, in a study of people the sample is a number of people chosen from a larger population [see population]. An environmental sample (for example, a small amount of soil or water) might be collected to measure contamination in the environment at a specific location. (Source: ATSDR Glossary of Terms   )

Scientific Consensus

The Scientific Consensus represents the position generally agreed upon at a given time by most scientists specialized in a given field. (Source: GreenFacts)



Sewage refers to waste-water from homes and industry which is collected and carried away in sewers (pipes or tunnels). When raw waste-water is cleaned in treatment plants the waste product is sewage sludge, which can be used as a fertiliser under certain conditions or deposited in landfills. (Source: GreenFacts )


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 )


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  )



Individuals or groups that are affected by a decision and have an interest in its outcome. (Source: TDM Encyclopedia Glossary   )

Surface water

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


A surfactant is a substance that reduces the surface tension of a liquid in which it is dissolved.

When dissolved in water a surfactant gives a product the ability to remove dirt from surfaces such as the human skin, textiles, and other solids. (Source: GreenFacts)


When the combined effect of several forces operating is greater than the sum of the separate effects of the forces. (Source: Millennium Ecosystem Assessment  Glossary )

The Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection

The Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) is an advisory body, established in 1969, that advises the United Nations (UN) system on the scientific aspects of marine environmental protection.

At present GESAMP is jointly sponsored by nine UN organizations with responsibilities relating to the marine environment, and they utilize GESAMP as a mechanism for coordination and collaboration among them. GESAMP functions are to conduct and support marine environmental assessments, to undertake in-depth studies, analyses, and reviews of specific topics, and to identify emerging issues regarding the state of the marine environment. GESAMP itself today consists of 16 experts, drawn from a wide range of relevant disciplines, who act in an independent and individual capacity. Studies and assessments are usually carried out by dedicated working groups, most of whose members are not sitting members of GESAMP but part of the broader GESAMP network.


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

Trophic level

A trophic level of an organism is its position in a food chain.

Levels are numbered according to how far particular organisms are along the chain from the primary producers [plants] at level 1, to herbivores (level 2), to predators (level 3), to carnivores or top carnivores (level 4 or 5).

Fish at higher trophic levels are typically of higher economic value. (Source: Millennium Ecosystem Assessment Figure 1.3. Decline in Trophic Level of Fisheries Catch Since 1950 )



The lowest part of the atmosphere from the surface to about 10 km in altitude in mid-latitudes (ranging from 9 km in high latitudes to 16 km in the tropics on average) where clouds and "weather" phenomena occur. In the troposphere temperatures generally decrease with height. (Source: GreenFacts)


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 )

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