Properties Of Pollutants Flashcards
What do the properties of pollutant determine?
- the length of time it may cause a problem
- the level of harm it may cause
- where and how far it might travel
What is it important to understand properties?
They can help to anticipate what might happen and even prevent them from
Explain state of matter as a pollutant property
Whether a pollutant is a solid, liquid or gas affects its ability to be dispersed by moving water or water
what are solid pollutants more likely to do?
Be deposited close to the source
What are gas pollutants more likely to do?
They are easily transported in the atmosphere- can go further than solids
What are the different forms of energy that pollutants can be?
Noise, Heat, Ionising radiation, light
What impact does the energy form have as a pollutant property?
It has a wide variation of impacts because of the way energy behaves
How can density be an important property of pollutants?
The density will effect dispersal
Why does the density of a pollutant affect its dispersal?
Denser materials require more kinetic energy to keep them suspended so are more likely to be deposited close to the source
Name a high density pollutant
Lead dust
What impact can the density of pollutants that are gases have?
Some gases are denser than air, this means they settle close to the round if there is insufficient wind
Example of an incident where there was a high density gas pollutant involved
Hydrogen cyanide was released in Bhopal, India in 1984
It remained very close to the source
What is persistence/ how is it a property of pollutants?
It is a measure of the length of time that a pollutant remains in the environment before it chemically breaks down (degrades)
How can the persistence be measured?
As the time it takes for half a pollutant to break down
The measurement of time for pollutant to degrade is also known as what?
The environmental half life
What is the measurement of the time taken for pollutants to degrade also known as?
The environmental half-life
Why is the environmental half-life not a precise measurement?
Because the rate of breakdown can be affected by environmental conditions
E.g. light, temp, oxygen levels, PH, presence of bacteria
Give 2 examples of high persistence pollutants
-CFCs
- organochlorine insecticides e.g. DDT
Give 2 examples of low persistence pollutants
- sewage
- Pyrethroid insecticides
How can the types of degradation be categorised?
By the features that cause the break down
What are the 3 types of degradation and what is each caused by ?
Biodegradation: caused by living organisms (usually bacteria)
Photodegradation: caused by light
Thermal degradation: caused by heat
What is the toxicity of a pollutant?
A measure of how poisonous a substances is to a living organism
How does the toxicity of pollutants cause harm usually?
By damage to proteins- especially the inhibition of enzyme action
Give 4 examples of toxic pollutants
-carbon monoxide
-lead
-acids
-cyanide
Explain why carbon monoxide is a toxic pollutant
It prevents blood from carrying oxygen (or CO2 to leave the body) by binding to Hb in red blood cells
Explain why lead is a toxic pollutant
It inhibits enzyme action in nerve cells
Explain Acids as toxic pollutants
They inhibit protein action by changing the molecular shape- e.g. active site of an enzyme
Explain why cyanide is a toxic pollutant
It inhibits enzymes involved in aerobic respiration