Glossary
Absorption The contact that occurs with a pollutant – some pollutants can be absorbed through the skin or other body membranes.
Bioaccumulation The term used to describe how the effects of heavy metals and other persistent pollutants are magnified (or accumulated) as they move up the food chain.
Diffuse sources Occurs when there is no single point where the pollutant/s enter the environment. The waste is spread over a larger area, with less defined points of emission.
Dispersal The way that a pollutant is spread or moves around the environment. Dispersal can be airborne, water-borne or through soil moved by vectors (eg. machinery, footwear etc.)
Exposure The degree of time spent near or in contact with the pollutant. The level of exposure is related to the characteristics of the pollutant.
Ingestion When the pollutant is taken in via the mouth.
LD50 (Lethal Dose) Is the term used to describe the dose of a substance that is sufficient to kill a percentage (50%) of the specified test animal within a specified period. The smaller the LD50 dose the more toxic a substance is. The lethal dose figures refer to acute toxicity and do not give an indicator of cumulative effects over time.
Persistence The time that the pollutant takes to break down. Substances that are not easily broken down are said to be persistent. A pollutant is degradable if it breaks down with sunlight, soil, water or in chemical reactions.
Pollutant Is something that when released into the environment causes some harm or alters the environment in a negative way.
Point sources Occurs when waste comes from a single point, specified site or location. Atmospheric emissions from a smoke stack or a discharge pipe for liquid emissions.
Sink A place or process that removes stores or absorbs the pollutant. Wetlands are a pollutant sink for heavy metals and other materials. Atmospheric Carbon Dioxide dissolves in sea and is stored in organic matter such as plants and vegetation.
Source The origin or starting point where a pollutant enters the environment.
Toxicity Is the measure of harm (death or illness) a substance can cause in humans and other living things. Toxicity is defined as acute and chronic respectively this refers to single and repetitive exposure.
Volatile Highly flammable, evaporates easily. eg. petrol, LPG.
