index: Pollution, the dirty face of development
                     Glossary

 

(Pollution, the dirty face of development)

 

[A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ]

(Note - Greek letters are written out by name - alpha, beta etc.)

(For a much more complete glossary of environmental terms, see [here])

 

 

- A -

algal bloom
A sudden spurt of algal growth due to high concentrations of plant nutrients (eutrophication), which can affect water quality adversely. Blooms can result in oxygen depletion and biological impacts such as fish kills.

[close the glossary]

anoxia
The condition of a lack of oxygen dissolved in the waters of a lake, swamp, river or sea. It generally concerns water on the bed. The values that indicate this condition are between  0-1,0 mg/l. Anoxia causes suffering and death in the organisms which live in the water on the bed.

[close the glossary]

- B -

bioaccumulation
The accumulation of a chemical in tissues of an organism to levels greater than in the surrounding medium. Accumulation may take place by breathing, swallowing or dermal contact.

[close the glossary]

biogeochemical cycle
The transformation and transport of substances within and among the atmosphere, biosphere, hydrosphere, and lithosphere via biological, geological, and chemical processes that are often cyclic in nature. The biosphere is a closed ecological system with finite resources and is maintained in equilibrium by grand-scale recycling. Under natural conditions organic and certain inorganic materials in the biosphere are continually recycled by processes including photosynthesis and respiration, nitrogen fixation and denitrification (see nitrogen cycle), evaporation and precipitation, and diffusion by wind and water action. But the introduction of massive quantities of waste matter at any point in the biosystem may "overload" it, disrupting the natural recycling mechanisms.

[close the glossary]

biomagnification
This is a general term applied to the sequence of processes in an ecosystem by which higher concentrations are attained in organisms of higher trophic level in the food chain. The process by which xenobiotics increase in body concentration in organisms through a series of prey-predator relationships from primary producers to ultimate predators, often human beings. Biomagnification along a food chain will result in the highest concentrations of a substance being found at the top of the food chain.

[close the glossary]

- C -

chlorofluorocarbons (CFCs)
A hydrocarbon in which all the hydrogen atoms have been replaced by chlorine and fluorine. Fluorocarbons are used as a feedstock, as a refrigerant in refrigerators and air conditioners, as a solvent and as a blowing agent of plastic foam, as propellant for households (aerosol sprays) and in some asthma inhalers. Because CFCs are not destroyed in the lower atmosphere (troposphere) they drift into the upper atmosphere (stratosphere). Here CFCs undergo photodissociation promoted by UV light, and chlorine atoms are formed which are responsible of destructive effects on the ozone layer (ozone depletion). Their use has been generally prohibited by the Montreal Protocol (1987), and hydrochlorofluorocarbons are now used as CFC substitutes.

[close the glossary]

composting
Is the controlled biological decomposition of organic material in the presence of air to form a humus-like material. Compost is the relatively stable humus material that is produced from a composting process in which bacteria in soil mixed with garbage and degradable trash break down the mixture into organic fertilizer.

[close the glossary]

- D -

- E -

ecosystem
Is a naturally occurring assemblage of organisms (plant, animal and other living organisms—also referred to as a biotic community or biocoenosis) living together with their environment (or biotope), functioning as a unit of sorts. The term ecosystem first appeared in a 1935 publication by the British ecologist Arthur Tansley, and includes the physical and biological components of an environment considered in relation to each other as a unit. An ecosystem is a dynamic and complex whole, interacting as an ecological unit, a structured functional unit in equilibrium, characterized by energy and matter flows between the different elements that compose it.

[close the glossary]

Environmental Chemistry
Is the study of the sources, reactions, transport, effects, and fates of chemical species in water, soil, air, and living environments (biogeochemical cycles, etc) and of the effects of anthropic activity and technology on them (pollutant emission, etc.).

[close the glossary]

externalities
An externality occurs in economics when a decision (for example, to pollute the atmosphere) causes costs or benefits to individuals or groups other than the person making the decision. Pollution by a firm in the course of its production which causes nuisance or harm to others, is an example of a negative externality, external cost, or external diseconomy.

[close the glossary]

- F -

food chain
A graphical representation of the sequence of organisms, each of which uses the next, lower member of the sequence, as a food source. The chain starts with plants or other autotrophs (an organism that satisfies its need for organic food molecules by using the energy of the sun, or of the oxidation of inorganic substances, to convert inorganic molecules into organic molecules. Green plants are autotrophs), which are eaten by herbivores. The herbivores are eaten by carnivores. These are eaten by other carnivores. When any organism dies, it is eaten by tiny microbes (detrivores) and the exchange of energy continues.

[close the glossary]

food web
The complex and interconnected web of feeding relationships by which energy and nutrients are transferred from one species to another in an ecosystem.

[close the glossary]

- G -

Green Chemistry (Sustainable Chemistry)
Green Chemistry means chemistry for the environment, a fundamental new philosophy of thinking that can help chemists in research and production to develop more eco-friendly and efficient products and processes. Green chemistry is the attempt to prevent pollution, to reduce or eliminate the use and generation of hazardous substances and to design chemical products and processes to reduce the harm they cause to  ecosystems. Thus, environmental chemistry is necessary for green chemistry to be possible, since how different chemicals behave in the environment to be able to make things better, must be known. Thanks to the 1990 US Pollution Prevention Act, and the 1995 Presidential Green Chemistry Challenge Grants, there are now many examples of innovative and economically competitive Green Chemistry technologies in the chemical industry.

[close the glossary]

- H -

hazardous substances
Any material that poses a threat to human health and/or the environment. Typical hazardous substances are toxic, corrosive, ignitable, explosive, or chemically reactive. Hazard refers to a condition or physical situation (for instance the exposure to a hazardous substance) with a potential for an undesirable consequence, such as harm to life or environment. Risk, on the other hand, is a measure of the probability that damage to life, health, or the environment will occur as a result of a given hazard. Risk is the product of the hazard multiplied by dose. Dose is the actual quantity of a hazardous substance to which an organism has been exposed.

[close the glossary]

- I -

- J -

- K -

- L -

landfill
Sanitary landfills are disposal sites for non-hazardous solid wastes spread in layers, compacted to the smallest practical volume, and covered by material applied at the end of each operating day. Secure chemical landfills are disposal sites for hazardous waste, selected and designed to minimize the chance of release of hazardous substances into the environment.

[close the glossary]

- M -

methylmercury
A neurotoxin deriving from the microbiological methylation of mercuric ions, it may be found in high concentrations in the biota of aquatic ecosystems. Here methylmercury undergoes biomagnification along the food chain. Seafood consumption is the main way methylmercury is taken up by humans.

[close the glossary]

- N -

nitrogen oxides
NOx is the generic term for nitrogen oxides, a group of highly reactive gases, all of which contain nitrogen and oxygen in varying amounts. The most important are nitrogen monoxide NO (colourless and odourless), nitrogen dioxide NO2 (reddish-brown, pungent odour) with minor amounts of NO3 and N2O4. It forms by direct combination of oxygen and nitrogen under electric discharge (lightening) or when fuel is burned at high temperatures, as in a combustion process. The primary sources of NOx are motor vehicles, electric utilities, and other industrial, commercial, and residential sources that burn fuels.

[close the glossary]

- O -

ozone
Ozone in the upper atmosphere (stratosphere) is able to absorb the major part of the sun's ultraviolet radiation and therefore prevent this dangerous radiation from reaching the surface. Without a protective ozone layer in the atmosphere, animals and plants could not exist. A drastic depletion of the ozone layer over the Antarctic, the "ozone hole", was noticed in the 70s, and depletion was found to be caused chiefly by ozone reacting chemically with chlorine released from chlorofluorocarbons (CFCs). The effects on the ozone layer, if human use of CFC gases was to continue at an unaltered rate, were reckoned and, in 1998, the Montreal Protocol banned the production of CFCs.

[close the glossary]

- P -

particulate matter, (fine particles, aerosol)
Particles coming from natural (volcanic eruptions, forest fires) or anthropic sources (combustion-based processes), such as carbon and ash, which gradually fall from the smoke plume downwind from the source. Aerosol can be sampled on the basis of the average aerodynamic diameter (dM): we often refer to PM10 (dM < 10 x 10-6 m) e PM2.5 (dM < 2.5 x 10-6 m). Epidemiological studies unambiguously pointed out the role of PM2.5 annual mean concentrations in enhancing inflammatory and allergic responses in the respiratory system.

[close the glossary]

photochemical smog
Under adverse weather conditions and/or in the presence of air pollution conditions, volatile organic compounds (VOCs) and nitrogen oxides interact under the action of sunlight to produce a plethora of secondary pollutants, part of which (for instance ozone) are toxic to vegetal and animal life. Smog forms a brownish-yellow haze primarily over urban areas, and is most prevalent in the summer months, when there is the most sunlight and temperatures are the highest.

[close the glossary]

pollutant
Contaminant that adversely alters the physical, chemical, or biological properties of the environment. The term includes nutrients, pathogens, toxic metals, carcinogens, etc. Pollutants are classified as either Primary or Secondary. For example, a primary air pollutant is one that is added directly to the air from a given source. An example of a primary air pollutant would be carbon monoxide because it is added to the air as a by-product of combustion. A secondary air pollutant is formed in the atmosphere through chemical reactions. An example of a secondary air pollutant would be the formation of ozone in photochemical smog.

[close the glossary]

pollution
Contamination of the environment as a result of human activities. The term pollution refers primarily to the fouling of air, water, and land by wastes (air pollution, water pollution, solid waste).

[close the glossary]

- Q -

- R -

radon
A colourless, naturally occurring, radioactive, inert gas formed by radioactive decay of radium atoms in soil, rocks and uranium ores. Being a gas, it can enter buildings through openings or cracks in the foundation. The radon gas itself decays into radioactive solids, called radon daughters. The radon radioactive daughters (polonium, lead, bismuth) attach to dust particles in the air, and can be inhaled. The inhalation of radon daughters has been linked to lung cancer.

[close the glossary]

reclamation of contaminated sites
Contaminated land is defined as land "where there is a serious threat or risk to health, flora and/or fauna", and is generally reserved for areas where the pollutant or harmful substance is man-made or is put there by humans. Besides posing a potential hazard to human health, and threatening the environment (natural and built), it is a risk to investment and regeneration and limits land development - particularly in urban areas. There are more than 10,000 identified contaminated sites in Italy.

[close the glossary]

- S -

sustainability, sustainable development
Meeting the needs of the present generation without compromising the ability of future generations to meet their own needs or the health of the planet. Essentially it is about living, working and ordering society in ways which are environmentally "sustainable", encouraging reduction of pollution, re-use of resources, promoting biodiversity etc. The term originally applied to the exploitation of natural resources, where the focus was long-term. Today, it applies to many disciplines, including economic development, environment, food production, energy and lifestyle.

[close the glossary]

- T -

thalidomide
An emblematic example of a chemical applied to health. Its use in treating sickness during pregnancy in the 1960s resulted in birth defects. The birth defects were caused because thalidomide changes the growth and development of new blood vessels (angiogenesis) in the developing babies. Forty years later, researchers are hoping to use thalidomide to stop cancers from developing new blood vessels. This should reduce the cancer's supply of oxygen and nutrients, which, it is hoped, will cause the tumour to shrink, or at least to stop growing. It is most commonly used to treat a type of cancer known as myeloma.

[close the glossary]

thermal inversion
In meteorology, an atmospheric condition in which the air temperature rises with increasing altitude, holding surface air down and preventing dispersion of pollutants.

[close the glossary]

- U -

- V -

validation
The process by which the integrity, correctness and fulfilment to precisely defined criteria (for example addressed by statistics) of series of analytical data are established. In environmental modelling (for example climate modelling), the most obvious way to validate a climate model is to use it to analyze past events, and then see whether its simulated prediction 'came true,' or how close it was to being correct.

[close the glossary]

volatile organic compounds (VOCs)
This class of chemicals includes a plethora of organic molecules, aliphatic and aromatic hydrocarbons, halogen-containing compounds, etc. They are released into the atmosphere by natural processes (terpenes from vegetation) or anthropic activities (accidental spillouts from chemical plants, or during transport, storage or use of low-boiling organic products). They are co-responsible for the formation of  photochemical smog.

[close the glossary]

- W -

- X -

- Y -

- Z -