1.5 - Humans And Popullations Flashcards
What does pollution refer to
Pollution refers to the introduction off harmful substances or agents into the environment
What are the three major problems of pollution
- 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
What 2 things can pollution be
- 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)
What does pollution result in
Pollution results from the release of substances that degrade the sustainable quality of air, water, and soil, negatively impacting human quality of life
What are the main sources of pollution
Pollutants can come in various forms, including:
Organic or inorganic substances
Light, sound, or heat energy
Biological agents
Invasive species
What is the biggest source of pollution
Human activities, including the combustion of fossil fuels, are the major sources of pollution
Why is the defining of pollution levels challenging
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
What are four major sources of pollution and what do they lead to
- Agriculture
- Pesticides, fertilisers, animal waste
- Bioaccumulation, biomagnification, eutrophication - Domestic waste
- Solid domestic waste, sewage, chemical waste
- Contamination of groundwater, release of methane, eutrophication, disease - Transport
- Exhaust fumes from vehicles, runoff from roads
- Air pollution, respiratory problems, climate change, contamination of streams and soils - Natural
- Volcanic ash, particulate pollution
- Respiratory problems, acid rain, habitat destruction
What criteria can pollution be classified as
-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
What is point source pollution
Point source pollution comes from a single identifiable source, such as a factory or a sewage treatment plant
What is non point source pollution
Non-point source pollution comes from dispersed sources, such as runoff from agricultural fields or urban areas
What is persistent pollution
Persistent pollution does not degrade or break down quickly, such as heavy metals or certain pesticides
What is biodegradable pollution
Biodegradable pollution can be broken down by natural processes, such as organic waste
What is the acute effect
Acute effects of pollution occur in a high concentration for a short period of time, such as an oil spill
What is the chorionic effects
Chronic effects of pollution occur over a long period of time in lower concentrations, such as air pollution from vehicle emissions
What are primary pollutants
Primary pollutants are directly emitted into the environment, such as carbon monoxide or particulate matter from burning fossil fuels
What are the secondary pollutants
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
What is DDT
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
What is DDT used for
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
What side effects does DDT have
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
What is biomagnification
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.
What has the conflict between DDT and the environment lead to
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
What does the use of DDT highlight the importance of
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
What are the major causes of pollution
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
What are the three main stages of leading to the impact of t of pollutants on the environment
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
What are the three stages for managing the impacts of pollutants
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
How can modern technology reduce the impact of pollution
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)
