Properties and Effects of Environmental Pollutants

Vocabulary flashcards covering pollutant properties, pathways, mechanisms, toxicity, and environmental impacts based on lecture notes.

Pollution

The release of substances or forms of energy into the environment that cause harm, especially to living organisms.

Hydrogen cyanide (Bhopal, 1984)

A gas denser than air released in Bhopal, India, in $1984$ that settled close to the ground and remained near the source due to insufficient wind.

Persistence

A measure of the length of time that a pollutant remains in the environment before it breaks down chemically (degrades).

Environmental half-life ($T_{ENV}$)

The time it takes for half of a pollutant to break down in the environment under specific environmental conditions.

Biodegradation

The process of pollutant breakdown caused by living organisms, usually bacteria.

Photodegradation

The breakdown of a polluting substance caused by light.

Thermal degradation

The breakdown of a polluting substance caused by heat.

Toxicity

A measure of how poisonous a substance is to living organisms, usually caused by damage to proteins or inhibition of enzyme action.

Carbon monoxide

A toxic pollutant that prevents blood from carrying oxygen by binding to haemoglobin in red blood cells.

Cyanide

A toxic pollutant that inhibits enzymes involved in aerobic respiration.

Specificity

A property of toxic pollutants describing variations in toxicity to different groups of organisms, where specific toxins are more toxic to some groups than others.

Pyrethroid insecticides

Insecticides characterized by low persistence and high toxicity to insects and fish, but low toxicity to mammals.

Primary pollutant

A pollutant that is directly released into the environment by human activities.

Secondary pollutant

A pollutant produced by chemical reactions between one or more primary pollutants, often involving non-pollutants.

Adsorption

The process by which pollutants become attached to the surface of materials such as soil particles or aquatic sediments, temporarily immobilizing them.

Bioaccumulation

The process by which the concentration of a substance within an organism increases over time, usually involving long-term ingestion of small doses of a liposoluble pollutant.

Biomagnification

The process where bioaccumulated substances become progressively more concentrated as they pass along a food chain into smaller biomass at successive trophic levels.

Synergism

A phenomenon in pollution where the effects of two or more pollutants interact to produce a different, usually more serious effect, without creating a new pollutant.

Mutagens

Agents that cause changes in the chemical structure of DNA by damaging chromosomes through structural rearrangement.

Gonadic effects

Mutational effects occurring in an egg, sperm cell, or embryo that may cause a birth abnormality in the produced offspring.

Somatic effects

Mutational effects in general body cells that cause abnormal cellular function or lead to uncontrolled cell division (cancer).

Carcinogens

Mutagens that cause cancer by inducing cell multiplication, creating a mass of tissue called a tumour.

Teratogens

Agents that cause birth abnormalities by inhibiting protein and enzyme function to prevent normal gene expression without altering the DNA structure.

2,4,5-T

A herbicide (no longer used) that functions as a teratogenic pollutant.

Mobility

The ability of a pollutant to move within the environment, dependent upon its state of matter, density, and water solubility.