I/GCSE Biology - Human Impact on the Environment 

In this post, we'll talk about the human effects on the environment in I/GCSE Biology!

• Pollution of waterways and air ➡️ chemical, heat, light and noise pollution
• Harmful chemicals made which can’t be decomposed
• Destruction of animal habitats leading to endangered and extinct animals

Let's look at the graph shown below

• This graph shows the population increasing gradually from 1000 to 1800
• After 1800, it begins increasing rapidly and continues to do so until 2000 (and afterwards)

In I/GCSE Biology, it's important to remember the following points!

• Several rules when building houses/ roads etc.
• Must consider wildlife/ pollution/ ancient monuments
• Must protect rare species e.g. SSSI will have stricter building regulations
• Area must be landscaped if quarrying is included
• To maintain biodiversity

In I/GCSE Biology, it's important to know what water pollution is!

• Water pollution caused by waste disposal, untreated sewage etc.
• Too much to be decomposed by natural processes
• Encourages bacteria to multiply, which then use all the oxygen in the water
• Disease causing microbes may contaminate the water and encourage water spread diseases, such as cholera and typhoid
• This makes it dangerous to eat animals coming from the water source

In I/GCSE Biology, eutrophication is commonly asked in the exam!

• Fertilisers from agriculture (washed into waterways by the rain) or nitrates found in sewage (discharged into rivers etc.) fertilise microscopic plants in the water. This could lead to algae bloom (sudden growth in algae population).
• The algae will then prevent light from reaching the plant life at the bottom of the lake/ river
• These plants die and decompose, allowing bacteria to multiply.
• The bacteria uses up oxygen and fish and other water animals die due to lack of oxygen.

Lastly, you should also understand what bioaccumulation is!

• Pesticides, also used in agriculture, can have different negative effects on the environment:

1. If microscopic organisms, usually in water, consume a small amount of these chemicals, it won’t be harmful, however, they cannot digest them as they can normal food
2. An animal- such as a small fish- above the microscopic organisms would consume a large amount of its prey, and therefore a large amount of the chemical pesticide
3. There is therefore a higher concentration of chemical in that fish than in the microorganism
4. This chemical continues to build up throughout the food chain, until the top predator- or one of the top predators- such as a heron or other bird-, consumes too much of the chemical and it becomes toxic to that animal and the animal is poisoned and dies.

And we're done with this topic! Well Done!

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Drafted by Alyssa (Biology)

References:

1. "Water and Air Pollution", https://www.history.com/.image/ar_16:9%2Cc_fill%2Ccs_srgb%2Cfl_progressive%2Cq_auto:good%2Cw_1200/MTU3ODc5MDg1NjI5OTA4Mjk3/nature-pollution.jpg
2. "BTS", https://btsconsultant.com/uploads/courses/Environmental%20Impact%20Assessment.jpg
3. "Effects of water pollution on living and non-living things", https://eschooltoday.com/learn/wp-content/uploads/2020/10/effects-of-pollution-on-ecosystems.jpg
4. "What is Bioaccumulation?", https://images.squarespace-cdn.com/content/v1/5914f3bc3e00be9632fe1a5a/1566323267969-2Q33W9T0CT312UIVBF8J/Bioaccumulation.png?format=1000w