Glossary
- algal blooms
- A rapid increase in the population of algae in an aquatic system.
- bioaccumulation
- The accumulation of a substance, such as a pesticide or another organic chemical, in the tissues of a living organism.
- bioavailability
- Of a substance, the degree to which or rate at which that substance is absorbed or becomes available at the site of physiological activity, i.e. the extent to which it can be taken up by living organisms.
- biomagnification
- The sequence of processes in an ecosystem by which higher concentrations of a particular chemical are reached in organisms higher up the food chain.
- catalyst
- A substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.
- chemical speciation
- The chemical form or compound in which an element occurs in both non-living and living systems.
- colloidal
- Term referring to a system in which finely divided particles, which are approximately 10 × 10−10 m to 10 000 × 10−10 m in size, are dispersed within a continuous medium in a manner that prevents them from being filtered easily or settled rapidly.
- diffuse sources
- Sources of pollution (often small) that have no specific point of discharge.
- diffusion
- The movement of atoms or molecules from an area of high concentration to one of low concentration.
- dissociates
- In reference to ionic compounds (complexes or salts), to separate or split into smaller particles, ions or radicals, usually in a reversible manner.
- emulsion
- A mixture of two or more liquids that are normally immiscible.
- enzyme
- A substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction.
- homeostasis
- Maintenance of a constant internal environment.
- hydrological cycle
- The natural water cycle that describes the continuous movement of water on, above and below the surface of the Earth.
- nitrogen fixation
- The process by which nitrogen gas (N2) in the atmosphere is converted into ammonia (NH3).
- persistent organic pollutants
- (POPs) Organic compounds that are highly toxic, persist in the environment, bioaccumulate in human and animal tissue, and can be transported by wind and water. Most POPs are pesticides.
- point sources
- Single identifiable sources of pollution from which pollutants are discharged, such as a pipe.
- synergism
- Condition in which the interaction of two or more substances results in a combined effect that is greater than the sum of their separate effects.