Pollution key terms

Acoustic fatigue

Stress cracking of a material caused by repetitive vibrations induced by sound.

Acute

Exposure to a substance or symptoms that appear rapidly.

Aerodynamics

The study of airflow over surfaces to allow the design of surfaces that reduce wind resistance, turbulence, friction and noise generation.

Baffle mounds

Embankments that absorb and deflect noise, especially around mines, airports and major roads.

Bag filter

A method reducing atmospheric pollution caused by smoke and particulate matter.

Becquerel (Bq)

The Becquerel is the unit of activity of a radioactive source. 1 Bq = I nuclear decay per second. It is usually related to a standard mass of material.

Bioaccumulation

The increase in concentration of a substance in living tissue as it is absorbed and stored faster than it is broken down and excreted.

Biodegradable

A material that can be broken down by living organisms, usually bacteria.

Biomagnification

The progressive bioaccumulation of a material along a food chain e.g. organochlorine insecticides, PCBs, heavy metals.

Bioremediation

Cleaning up a contaminated site using living organisms such as bacteria that chemically degrade the pollutants or plants that absorb the pollutants.

Biotic index

A measure of pollution based on the presence, abundance and state of health of selected living organisms eg lichens for acid rain, aquatic invertebrates for water pollution.

Bund wall

A wall that surrounds a tank which would contain the contents if the tank leaked or burst.

Carcinogen

A substance or energy form that can cause cancer.

Catalytic converter

A device that reduces emissions of pollutant gases from petrol and diesel engines. Catalysts such as platinum, palladium and rhodium catalyse reactions with oxides of nitrogen, carbon monoxide and unburnt hydrocarbons.

Chronic

Exposure to a substance or symptoms that appear over long periods of time.

Clean Air Act (1956)

UK legislation to control smoke pollution by the establishment of Smoke Zones by making Control Orders in large urban areas.

Constant descent angle

A method of approaching an airport where the aircraft descends at a constant angle, usually 3°.

Contamination

Pollution caused by the pollutant staying in contact or mixing with materials such as soil, atmosphere, water or living organisms.

Critical group monitoring

A method of monitoring pollutants, particularly radioactive discharges. If the members of the public that are most at risk are safe, then so is everyone else.

Critical pathway analysis (CPA)

The prediction of the routes that an effluent will take in the environment, to assess pollution risk.

Cyclone separator

Equipment used to remove suspended particles from gaseous effluents.

dB scale

A logarithmic scale used to measure sound levels.

Degradability

A measure of the ease with which a material breaks down.

Desulphurisation

The removal of sulphur or compounds containing sulphur such as sulphur dioxide.

Dry flue

gas desulphurisation (dry FGD)

Electrostatic precipitator

Equipment used to remove suspended particles from gaseous effluents by attracting them to electrically charged wires or plates.

Eutrophication

The process by which nutrient levels in a water body increase to excessive levels such that the growth and subsequent die

Exposure

In ionising radiation control, this refers to an object or person receiving radiation, but not necessarily coming in contact with the source.

Flue gas desulphurisation (FGD)

Processes that remove oxides of sulphur from gaseous effluents.

Gonadic

Relating to ovaries and testes.

Grays

A unit of energy absorbed from ionising radiation.

Half life

The time taken for half of a material to be lost or broken down.

Incineration

The breakdown of a waste by burning it.

Liposolubility

A measure of how easily a substance dissolves in fats and oils.

Neonicotinoids

A widely used group of insecticides. They have been linked with the deaths of bees, especially when they act synergistically with some fungicides.

Neurotoxin

A poison that affects the nervous system.

Organochlorines

Hydrocarbon

Organophosphate pesticide

Insecticide group eg parathion, malathion. They are not persistent but have high mammalian toxicity.

Persistence

A measure of the rate at which a material breaks down and therefore the length of time it remains.

Risk : benefit analysis

A method to inform decision making by comparing the risks of carrying out an activity with the benefits of doing so.

Sievert

A unit of absorption of ionising radiation absorption that takes into account the amount of energy absorbed and the Relative Biological Effectiveness of the type of radiation.

Smart motorways

A method of relieving traffic congestion which allows driving on the hard shoulder and reduces the speed limit during periods of heavy traffic flows.

Smog

Atmospheric pollution event involving smoke and fog (see also photochemical smog).

Somatic

An issue related to general body cells, but not the gonads (ovaries and testes).

Synergism

The process where the presence of two materials produces a greater effect than the sum of their individual effects.

Temperature inversion

A situation in the troposphere where the temperature is lower than normal so that relatively warm air lies above cold air.

Teratogen

A substance that interferes with gene function in a growing embryo so that a non

Toxicity

A measure of how poisonous a substance is, usually caused by its ability to cause enzyme inhibition.

Urea spray

A method of reducing NOx emissions eg from coal

Wet FGD

A method of removing sulfur oxides from effluent gases by dissolving them in a solution such as a spray of sodium sulphite solution.

Active traffic management (ATM)

A method of controlling road lane usage and speed limits to smooth traffic flow and reduce congestion.

As low as reasonably achievable (ALARA)

An approach to control of pollution, especially ionising radiation, where levels are kept as low as is practically achievable, taking into account economic and technological factors.

Best available technology not entailing excessive cost (BATNEEC)

An approach to pollution control where control technology is used that achieves the lowest emission levels, without costing so much that further marginal gains would risk their financial viability.

Blue baby syndrome/Methaemoglobinaemia

A health problem with several possible causes, where the haemoglobin in a baby’s blood does not carry enough oxygen. Nitrates in drinking water can be converted to nitrites which reduce the ability of haemoglobin to carry oxygen.

Cooling towers

A method of reducing the temperature of effluent water to reduce thermal pollution and deoxygenation.

Photochemical smogs

Atmospheric pollution events in which pollutants such as hydrocarbons, NOx and tropospheric ozone interact to produce more toxic pollutants such as PANs (peroxy acetyl nitrates).

Relative biological effectiveness (RBE)

This is a measure based on the amount of energy absorbed from ionising radiation which takes into account the damaging effects of the type of radiation.

Reverse thrusters

A method used on most aircraft to slow down after landing.

Sonograms

A graph showing the volumes of sounds at different frequencies.