Biology - Pollution Class Notes Flashcards
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.
Explain air pollution
The air is polluted by dust particles (which comes from different sources, such as sawing, drilling, construction work, etc). It is also polluted when the burning of fossil fuels creates pollutants like carbon particles that get added to the air (and are harmful for our lungs). When it settles on plants it blocks the stomata and reduces/slows down photosynthesis. It also causes chronic cough when it gathers in human lungs.
Fossil fuels like coal, natural gas from underground and crude oil are used in industries, factories, etc. They were formed millions of years ago from dead plants and animals under the soil that were in high pressure for too long.
Crude oil is the most common/most used to generate electricity or energy.
Other types of oil that are drilled out from underground and purified: petrol (contains lead), diesel, octane (most pure), kerosene, etc.
Their diff. is their price/cost.
Explain electric energy
Electric cars are better for the environment but they have the disadvantages of the cost of electricity, batteries, cost in general, charging points, etc.
Solar energy is not very costly to set up.
Explain the effects of carbon dioxide
Carbon dioxide causes global warming and climate change, like unnatural, extremes of weather (heat/cold waves, hurricanes and cyclones) This is happening due to the sea level rising and the rise in temperatures.
Explain the effects of a few harmful gases
When the hot gases - carbon monoxide/sulphur dioxide are mixed high in the air (with water droplets), they create a weak acid - acid rain. When acid rain falls on Earth, it harms plants, soil and aquatic organisms. Over time the condition gets worse. It also corrodes stone buildings over a long period of time.
Nitrogen oxide can also cause acid rain but it mainly creates smog (which is smoke and fog mixed). This layer of smog settles on cities.
How is smog formed
Smog is created when pollutants release from vehicles, factories and other human activities react with sunlight.
What are the two main types of smog? Explain them
Photo - chemical smog 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.
(UNDERSTAND)
Industrial smog comes from burning coal and oil which releases smoke, sulphur dioxide and other particles into the air. This happens mostly from industries that use coal for burning.
What is water pollution
It is the introduction of harmful substances into water bodies which affects living organisms and aquatic organisms.
Explain the types of water pollution
there are many types of water pollution bcs water comes from many sources. there are 3 main groups of pollutants:
a) chemical pollutants
b) biological pollutants
c) physical pollutants
What is sewage
It is the term used for wastewater that often contains feces, urine and laundry and kitchen waste.
Name some sub.s that pollute the water and where do they come from
Sewage and wastewater are two examples of substances that pollute the water. These are produced by households and industries. Plastic waste that also heavily pollutes/harms the sea when they are deposited.
What is groundwater pollution
When humans apply pesticides and chemicals to soils, these are washed deep into the soil ground by rainwater, causing water pollution underground.
