Pollution Flashcards
What are the properties of pollutants?
- toxicity
- reactivity
- state of matter
- density
- energy form
- persistence
- adsorption
- solubility
- synergism
- bioaccumulation
- biomagnification
- mutagenic
- carcinogenic
- teratogenic
What is pollution?
the term given to a variety of events and processes that d harm to the planet but especially living organisms
What can pollutants be?
- a material ie CO2
- forms of energy ie radiation
What is persistence?
A measure of how long it takes for a pollutant to chemically break down
What is mobility?
How easily the material can move in the environment
What is adsorption?
The process by which a solid holds molecules of a gas or liquid or solute as a thin film - how adhesive it is.
What is solubility?
A measure of the ease with which the molecules of a
material (the solute) separate and become dispersed in a liquid (the
solvent).
What is bioaccumulation
Bioaccumulation is the process by which the
amount of substance in a living organism
increases.
What is biomagnification
Results in pollutants that bioaccumulate to become
more concentrated along a food chain.
What is synergism?
Synergism is the interaction between the effects of different
substances that exaggerates the overall effect.
What is mutagenic action
A mutagen is a material or form of energy that causes chemical
changes to DNA.
What is carcinogenic action
A carcinogen is a mutagen that causes body cells to start to
multiply in an uncontrolled way.
What is teratogenic action
A teratogen causes non-inherited birth
abnormalities.
What factors affect the dispersal of pollutants
- water currents
- air and wind currents
- temperature inversions
- presents of adsorbent materials
What is meant by air, wind and water currents
- How far pollutants are dispersed
- the direction and area it will disperse over
- how much of the pollutant is dispersed
How do pollutants normally disperse
Temperatures in troposphere decline with increasing altitude, allowing pollutant gases to rise, disperse and become diluted. This is because the warm air causes the pollutants to become less dense but more buoyant
What is temperature inversion?
A break from normal troposphere temperature gradients. Air higher in the troposphere is warmer than air closer to the ground.
What factors effect the formation of
temperature inversions?
- Valleys: colder, denser air can collect.
- Low wind velocity: temperature layers do not mix.
- Cloudlessness: infrared energy radiates out, allowing the ground to
cool more quickly. - Water vapour: if mist or fog forms close to the ground this reflects
more sunlight, so the ground is cooled less. - Light surfaces reflect more heat than dark surfaces. This is called
the albedo effect.
What affect does temperature inversions have on the dispersal of pollutants
- Pollutants become trapped
by the temperature
inversion. - They remain more dense
and less buoyant. - So do not disperse and
dilute.
What is the problem with adsorption?
- Pollutants may adsorb onto materials such as clay particles or organic materials in aquatic sediments.
- Adsorption may immobilise the pollutant and stop it causing
problems.
What factors affect the degradation of pollutants
- temperature (Chemical reactions occur more rapidly when temperatures are higher)
- light levels (Light can provide the activation energy for
chemical reactions) - oxygen (Oxygen is required for many chemical and biological
reactions, including those involving pollutants) - pH (affect the solubility of substances)
- Interaction with other pollutants (Some interactions may increase the
effects of a pollutant or its toxicity)
What is a point source
a single, identifiable source of pollution, such as a pipe or a drain.
- ie industrial wastes commonly discharge to rivers and sea in this way
What is a non point source
often termed ‘diffuse’ pollution and refer to those
inputs and impacts which occur over a wide area and are not easily attributed to a single source
- ie forestry land use, urban land use
What is a critical pathway analysis
Used to predict the movement of pollution in the environment, and how it can affect living organisms, locations and the severity
