Pollution + properties of pollutants 1 Flashcards
What is pollution?
Pollution is the term given to a wide variety of events and processes that do harm the planet, especially living organisms. It is the release into the environment of materials or forms of energy that do harm by causing changes that would not have normally occurred.
Name human activities that use pollution
- Resource extraction (e.g. mineral mining)
- Resource use (e.g. fuel combustion to power domestic appliance)
- Manufacturing (e.g. fuel combustion to drive factory machinery)
- Disposal of unwanted, worn out or superfluous goods (domestic waste and by-products from manufacturing)
- Food production (e.g. pesticides and fertilisers)
Name the factors that affect the behaviour of pollutants in the environment
- Mobility ( how and where they travel)
- State of matter (solid, liquid, gas)
- Chemical form ( element, inorganic compound, organic compound)
- Timescale of Action
- What they affect ( living organisms, non-living objects)
- Direct or indirect action
Name the major properties of pollutants
Toxicity Specificity Persistence Biodegradability Mobility Solubility Bioaccumulation Biomagnification Synergism Mutagenicity Carcinogenicity Teratogeniciry
What is meant by toxicity
It is a measure of how poisonous a material is. A toxic substance is poisonous and harm the biological processes that take place within living organisms.
How can a toxic substance cause harm
Most toxic substances cause harm by damaging proteins, especially enzymes that control biological reactions.
Name some toxic pollutants
Carbon monoxide Lead DDT Acids Neurotoxins
Why is carbon monoxide a toxic pollutant
Carbon monoxide binds to haemoglobin in the blood and prevents it carrying oxygen
Why is lead a toxic pollutant
Lead inhibits the enzyme in nerve cells
Why is DDT a toxic pollutant
DDT prevents the normal passage of nerve impulses between nerve cells by inhibiting enzyme action
Why are acids toxic pollutants
Acids (from acid rain or acid drainage from mine spoil heaps) change the shape of cell membrane and enzyme proteins so they do not function properly
What are neurotoxins
Toxins that damage the nervous system
Name 3 non- toxic pollutants
Sewage (causes deoxygenation of lakes and rivers)
Greenhouse gases (cause the Earth to become warmer)
CFCs (cause ozone depletion)
What is meant by deoxygenation?
The process of oxygen removal
What is meant by specificity
It is a measure of differing toxicities of a substance on different organisms. A specific substance is very toxic to some organisms and much less toxic to others. Therefore a particular dose or concentration may kill some organisms while others can survive when larger doses may have harmed them too.
