Unit 4 Env. Science

Point source

Waste that comes from a single point, specified site or location. Eg. Pipe or chimney

Diffuse Source

Occurs when there is no single point where waste the emissions enter the environment. Eg. Highway or landfill

Pollutant

Something that when released into the environment causes some harm or alters the environment in a negative way.

Source

The origin or starting point where a pollutant enters the environment

Sink

A place or process that removes stores or absorbs the pollutant. Wetlands are a pollutant sink for heavy metals and other materials.

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.

Toxicity

Is the measure of harm (death or illness) a substance can cause in humans and other living things.

Chronic toxicity

Causing harm over a long period of repeated exposures.

Acute toxicity

Causing harm after a single exposure

Dispersal / Transport mechanisms

The way that a pollutant is spread or moves around the environment. Dispersal can be airborne, water borne or in soils.

Exposure

The degree of time spent near or in contact with the pollutant. The level of exposure is related to the pollutant.

LD50

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

Environmental Risk Assessment (ERA)

Identify and evaluate the environmental risks of implementing policies.

Environmental Management System (EMS)

Audit, Plan, Implement and Monitor environmental policy to assess ongoing effectiveness of environmental practises.

Life Cycle Analysis (LCA)

Implement a 'whole of lifetime' analysis of a product to increase efficiency of resource use and disposal.

Environmental Impact Assessment (EIA)

Identify and evaluate the environmentla effects of a proposed development prior to major decisions being made.

Stakeholders

People, companies and government bodies with an interest in a project or development.