Biology - Pollution Flashcards
(16 cards)
What is pollution
Pollution is the introduction of harmful substances or energy into the environment, damaging our air, water, soil or living organisms.
Pollution affects human health, the ecosystem and the planet.
What is a pollutant
A pollutant is a substance which can harm living things when it gets into water, air or soil. Pollutants can cause illness, they can prevent organisms reproducing and can kill. Pollutants spread through food chains. They are absorbed by plants, then pass it to herbivores, then to carnivores and so on, damaging each link to the chain and sometimes destroying it altogether.
EXTRA NOTES:
Firstly, the pollutants in the soil (e.g. chemical fertilisers) are absorbed by the plants. Then it is passed on to the herbivores/primary consumers when eaten. As it is passed through the food chain, the amount of energy decreases whilst the pollutants increase as it is passed through the food chain. The pollutants remain in the bodies of the consumers as they cannot be excreted. Thus, these pollutants cause long - time harmful effects.
How is smog formed
Smog is created when pollution release from vehicles, factories and other human activities react with sunlight.
Describe air pollution and fossil fuels and random notes
The air is polluted by dust, smoke and fumes. Dust particles come from different sources - such as sawing, drilling or construction work, etc. The burning of fossil fuels creates pollutants like carbon particles which get added to the air and are harmful for our lungs. A few examples of fossil fuels are coal, natural gas from underground, crude oil, etc. These are used in industries, factories, etc. Fossil fuels were formed millions of yeats ago from dead plants and animals under the soil which have been in high pressure for too long. Crude oil is the most common/most used fossil fuel to generate electricity. Crude oil is not very pure, it cannot be used straight away and must be purified first. Some exaamples of fossil fuels are petrol, diesel, octane, kerosene. Petrol contains lead which is harmful. Diesel is the most crude. Octane is the most pure. The difference between these oils are their price/cost.
Electric energy - electric cars have disadvantages: cost of electricity, batteries, more expensive, charging points, etc.
Solar energy is not very costly to set up.
Carbon dioxide can cause global warming, hurricanes and cuclones as well as climate change (unnatural extreme heat/cold waves). This is happening due to the sea level rising and the rise in temperatures.
Harmful gases - carbon monoxide, sulphur dioxide. When mixed they can cause acid rain. when acid rain falls on Earth, it harms plants, soil and aquatic organisms. Over time the condition gets worse.
Nitrogen oxide can also cause acid rain but mainly it creates smog which is smoke and fog mixed.
When we burn fossil fuels, they release harmful gases FOR EXAMPLE carbon dioxide which mainly can cause global warming due to climate change.
What are the two main types of smog and describe them
There are two main types of smog:
1) Photo-chemical smog. This happens when sunlight reacts with gases from car exhausts like nitrogen oxide to produce ozone at ground level. It is common in cities with heavy traffic and hot, sunny weather.
2) Industrial smog. This type comes from burning coal and oil which releases smoke, sulphur dioxide and other particles into the air. This happens mostly from industries which we use coal for burning.
When gases release from cars, the air will lift the hot gases higher into the air where they will dissolve with water droplets and mix to make a weak aacid. When it falls to the ground, there will be negative effects. They can corrode stone buildings over a long period of time (erosion can happen). air can travel. The air must be controlled near the factories so as to not create such harmful gases.
What is water pollution
It is the introduction of harmful substances into water bodies which affects living organisms and aquatic organisms.
What are the types of water pollution
There are many types of water pollution because water comes from many sources. There are three main groups of pollutants:
a) chemical pollutants
b) biological pollutants
c) physical pollutants
What are some examples of water pollution
Sewage is the term used for wastewater that often contains feces, urine, laundry and kitchen waste. The sewage and wastewater that is produced by each household is chemically treated and released into the sea with fresh water. The sewage water carries harmful bacteria and chemicals that can cause serious health problems.
Short notes on chemical water pollution
Many industries and farmers work with/use chemicals that end up in the water. These include chemicals to control weeds, insects and pests.
Metals and solvents from industries can pollute water bodies. These are poisonous to many aquatic organisms.
Microbiological Pollution
In many communities in the world people drink water straight from a river or stream. sometimes there is a natural pollution caused by bacteria and protozoa. This natural pollution can cause fishes and other water organisms to die. They can also cause serious illness to humans who drink such water.
Ocean and marine dumping (a kind of waste, and pollution)
These are all the waste that we make everyday e.g.
a) Paper waste
b) Plastic, metallic and aluminium waste
In some countries these are deposited into the sea. All of these wastes take time to decompose.
ALGAL BLOOM
If decomposers find anything in water, they break it down (to carry our its function - clean up the environment as well) and the number of them increase which reduces the amount of oxygen in the water. The amount of fertilisers affect the algae in water as well (its growth increases) and it covers/spreads out all over the surface of water. There is a bad effect on the water because the oxygen reduces (and it is difficult for the marine animals/organisms to survive, so they die). This is known as algal bloom.
NUTRIENT POLUTION
Some wastewater, fertilisers and sewage contain high levels of nutrients. If they end up in water bodies, they help algae and weed growth in water (as it uses up those nutrients). This will make the water undrinkable. When there is too much algae, they will die which will be decomposed by bacteria. When bacteria increases, oxygen decreases (as they use up a lot of oxygen in the water) so other organisms in the water will die out due to oxygen starvation.
Plants in shallow water are also affected.
The harmful chemicals and pollutants enter into the food chain and stays in out body. As it goes down the food chain, the pollutants increase as it is not easily excreted and their concentration is also increased. (So it is very harmful for us).
We also have side effects if we drink water that is polluted due to the added chemicals in our body
BIOLOGY HOMEWORK QNA
Name some substances which pollute air and water and explain where they come from.
AIR -
Dust is an example of a substance which pollutes the air. These small particles come from a few sources like construction work, sawing, drilling, etc. Next, harmful gases like carbon monoxide and sulphur dioxide also pollute the air. When we burn fossil fuels in factories - such gases are produced. They spread out in the air and cause negative effects to the environment.
WATER -
Sewage and waste are two examples of substances that pollute the water. These are produced by households and industries. Plastic waste also hevily pollutes/harms the sea when they are deposited.
