1.5 - Humans And Popullations

Question 1

What does pollution refer to

Answer 1

Pollution refers to the introduction off harmful substances or agents into the environment

Question 2

What are the three major problems of pollution

Answer 2

• These substances cannot be rendered harmless by the environment at a rate that is greater than the rate of their release
• Pollution is harmful to organisms and can adversely affect normal environmental processes
• It is a major source of contamination of the Earth and atmosphere, making ecosystems and habitats toxic and unpleasant

Question 3

What 2 things can pollution be

Answer 3

• Natural (e.g. ash from volcanic eruptions) or human in origin (e.g. microplastics)
• Intentional (e.g. industrial waste discharged into rivers) or unintentional (e.g. accidental oil spills from oil tankers)

Question 4

What does pollution result in

Answer 4

Pollution results from the release of substances that degrade the sustainable quality of air, water, and soil, negatively impacting human quality of life

Question 5

What are the main sources of pollution

Answer 5

Pollutants can come in various forms, including:
Organic or inorganic substances
Light, sound, or heat energy
Biological agents
Invasive species

Question 6

What is the biggest source of pollution

Answer 6

Human activities, including the combustion of fossil fuels, are the major sources of pollution

Question 7

Why is the defining of pollution levels challenging

Answer 7

Defining pollution levels is challenging and depends on the nature of the environment. For example:
Oil slicks pose a more significant threat in Arctic areas than in tropical ones due to slower decomposition rates in colder environments
Pollution levels that do not pose a risk to healthy adults can still affect young children, the elderly, or asthmatics

Question 8

What are four major sources of pollution and what do they lead to

Answer 8

1. Agriculture
   - Pesticides, fertilisers, animal waste
   - Bioaccumulation, biomagnification, eutrophication
2. Domestic waste
   - Solid domestic waste, sewage, chemical waste
   - Contamination of groundwater, release of methane, eutrophication, disease
3. Transport
   - Exhaust fumes from vehicles, runoff from roads
   - Air pollution, respiratory problems, climate change, contamination of streams and soils
4. Natural
   - Volcanic ash, particulate pollution
   - Respiratory problems, acid rain, habitat destruction

Question 9

What criteria can pollution be classified as

Answer 9

-Point source pollution vs non-point source pollution
-Persistent pollution vs biodegradable pollution
-Acute effects of pollution vs chronic effects of pollution
-Primary pollution vs secondary pollution

Question 10

What is point source pollution

Answer 10

Point source pollution comes from a single identifiable source, such as a factory or a sewage treatment plant

Question 11

What is non point source pollution

Answer 11

Non-point source pollution comes from dispersed sources, such as runoff from agricultural fields or urban areas

Question 12

What is persistent pollution

Answer 12

Persistent pollution does not degrade or break down quickly, such as heavy metals or certain pesticides

Question 13

What is biodegradable pollution

Answer 13

Biodegradable pollution can be broken down by natural processes, such as organic waste

Question 14

What is the acute effect

Answer 14

Acute effects of pollution occur in a high concentration for a short period of time, such as an oil spill

Question 15

What is the chorionic effects

Answer 15

Chronic effects of pollution occur over a long period of time in lower concentrations, such as air pollution from vehicle emissions

Question 16

What are primary pollutants

Answer 16

Primary pollutants are directly emitted into the environment, such as carbon monoxide or particulate matter from burning fossil fuels

Question 17

What are the secondary pollutants

Answer 17

Secondary pollutants form when primary pollutants undergo physical or chemical reactions in the atmosphere, such as the formation of ozone from nitrogen oxides and volatile organic compounds

Question 18

What is DDT

Answer 18

Dichlorodiphenyltrichloroethane (DDT) was widely used as a pesticide from the 1940s until it was banned in many countries in the 1970s due to its environmental and health impacts
It is an example of a conflict between the utility of a ‘pollutant’ and its effect on the environment

Question 19

What is DDT used for

Answer 19

DDT is a powerful insecticide, so it was effective in controlling insect-borne human diseases, such as malaria (transmitted by mosquitoes) and typhus (transmitted by lice), particularly in tropical regions

Question 20

What side effects does DDT have

Answer 20

it was discovered that DDT was also causing harm to non-target organisms, such as birds and fish, through biomagnification
This means that top predators, such as eagles and falcons, were receiving high doses of DDT, which caused them to lay eggs with thin shells, resulting in reproductive failure

Question 21

What is biomagnification

Answer 21

Biomagnification, also known as biological magnification or bioamplification, is the increase in concentration of a substance, such as a pesticide, in the tissues of organisms at successively higher trophic levels in a food chain.

Question 22

What has the conflict between DDT and the environment lead to

Answer 22

The conflict between the utility of DDT in controlling diseases and its environmental impacts led to a ban on its use in many countries, including the United States
Its use has been restricted under the Stockholm Convention on Persistent Organic Pollutants
The use of DDT remains controversial, with some arguing that it should be allowed for use in disease control in areas where it is the most effective option, while others argue that the environmental impacts are too significant to justify its use

Question 23

What does the use of DDT highlight the importance of

Answer 23

DDT highlights the importance of considering the potential environmental impacts of any chemical or substance before it is used, particularly when it will be widely distributed into the environment
It also shows that sometimes a trade-off must be made between the benefits and the negative impacts of a substance

Question 24

What are the major causes of pollution

Answer 24

Human activities, such as farming and industrial practices, urbanisation, development of transport, and energy production, are the major causes of pollution
The amount of material released into the environment determines the impact

Question 25

What are the three main stages of leading to the impact of t of pollutants on the environment

Answer 25

Stage 1: Human activity producing the pollutant
Stage 2: Releasing of the pollutant into the environment
Stage 3: The impact of the pollutant on ecosystems

Question 26

What are the three stages for managing the impacts of pollutants

Answer 26

Changing human activity
Regulating and reducing quantities of pollutants released at the point of emission
Cleaning up the pollutants and restoring the ecosystem after pollution has occurred

Replace, regulate, restore

Question 27

How can modern technology reduce the impact of pollution

Answer 27

Modern technology can reduce the impact of pollution by managing these three stages of pollutant impacts, for example:
- Stage 1 could be managed by introducing electric and hybrid cars that use less fossil fuel

• Stage 2 could be managed by fitting catalytic converters to car exhaust systems or adding scrubbers to industrial chimneys to remove toxic chemicals and allow for their reuse
• Stage 3 could be managed by using synthetic membranes to capture chemical spills (e.g. mats designed to capture and hold hydrocarbons)